Rubber meets the road with new ORNL carbon, battery technologies
Recycled tires could see new life in lithium-ion batteries that provide power to plug-in electric vehicles and store energy produced by wind and solar, say researchers at the Department of Energy’s Oak Ridge National Laboratory.
By modifying the microstructural characteristics of carbon black, a substance recovered from discarded tires, a team led by Parans Paranthaman and Amit Naskar is developing a better anode for lithium-ion batteries. An anode is a negatively charged electrode used as a host for storing lithium during charging.
The method, outlined in a paper published in the journal RSC Advances, has numerous advantages over conventional approaches to making anodes for lithium-ion batteries.
“Using waste tires for products such as energy storage is very attractive not only from the carbon materials recovery perspective but also for controlling environmental hazards caused by waste tire stock piles,” Paranthaman said.
The ORNL technique uses a proprietary pretreatment to recover pyrolytic carbon black material, which is similar to graphite but man-made. When used in anodes of lithium-ion batteries, researchers produced a small, laboratory-scale battery with a reversible capacity that is higher than what is possible with commercial graphite materials.
In fact, after 100 cycles the capacity measures nearly 390 milliamp hours per gram of carbon anode, which exceeds the best properties of commercial graphite. Researchers attribute this to the unique microstructure of the tire-derived carbon.
“This kind of performance is highly encouraging, especially in light of the fact that the global battery market for vehicles and military applications is approaching $78 billion and the materials market is expected to hit $11 billion in 2018,” Paranthaman said.
Anodes are one of the leading battery components, with 11 to 15 percent of the materials market share, according to Naskar, who noted that the new method could eliminate a number of hurdles.
“This technology addresses the need to develop an inexpensive, environmentally benign carbon composite anode material with high-surface area, higher-rate capability and long-term stability,” Naskar said.
ORNL plans to work with U.S. industry to license this technology and produce lithium-ion cells for automobile, stationary storage, medical and military applications. ORNL has posted the solicitation titled, “Low-Cost, Graphite Anodes For Lithium-Ion Batteries,” in FedBizOpps (www.fbo.gov). The solicitation (#ORNL-TT-2014-08) closes Sept. 15. Other potential uses include water filtration, gas sorption and storage.
Paranthaman and Naskar, authors of a paper titled “Tailored Recovery of Carbons from Waste Tires for Enhanced Performance as Anodes in Lithium-Ion Batteries,” envision batteries featuring this technology being highly marketable. The paper is available at http://pubs.rsc.org/en/content/articlelanding/2014/ra/c4ra03888f#!divAbstract
Co-authors are Zhonghe Bi, Yunchao Li, Sam Akato, Dipendu Saha, Miaofang Chi and Craig Bridges. They are working with David Wood and Jianlin Li on a pilot manufacturing process to scale up the recovery of material and demonstrate applications as anodes for lithium-ion batteries in large-format pouch cells. Researchers expect these batteries to be less expensive than those manufactured with commercial carbon powders.
Harmony and Department of Mining Engineering at University of Pretoria launch
Mining Rock Engineering initiative
- Published on 14 June 2013
Research on a safer working environment in the hard-rock mining industry will henceforth be a very specific focus area at the University of Pretoria (UP).
This is the result of a donation of R4.7 million over 3 years by Harmony Gold Mining Company Limited (Harmony) to UP in order to establish a Chair in Rock Engineering and Numerical Modelling in the mining industry. The Harmony chair will be housed in the Department of Mining Engineering of the University’s Faculty of Engineering, Built Environment and Information Technology.
The aim of the chair will be to take part in leading research activities in the field of rock mechanics and numerical modelling in the mining industry. The chair is also aimed at producing research and learning outcomes to the benefit of Harmony, the University and the country as a whole. There will be opportunities for the development of products like software to support numerical modelling.
Apart from research and studies in the above-mentioned fields, efforts will also be made to establish a postgraduate qualification in rock mechanics. Expanding undergraduate teaching in rock mechanics and numerical modelling, specifically as a result of new research being done, will also be an important function of the chair.
Another important function of the Harmony chair will be to arrange much needed liaison between academic institutions and the industry in general, but specifically between Harmony and UP.
Harmony will further benefit from this donation through its interaction with international leaders in the field of rock mechanics and numerical modelling research, as well as the interaction with under- and postgraduate students by way of student projects.
Mr Graham Briggs, chief executive officer of Harmony, said: “Ensuring the safety of each of our mineworkers is Harmony’s top priority. Therefore, further research and development to ensure even safer underground conditions are of the utmostResearch on a safer working environment in the hard-rock mining industry will henceforth be a very specific focus area at the University of Pretoria (UP).
Scientists Discover Green Method for Mining Gold
scientists have struck gold in the laboratory. They have discovered an inexpensive and environmentally benign method that uses simple cornstarch—instead of cyanide—to isolate gold from raw materials in a selective manner.
This green method extracts gold from crude sources and leaves behind other metals that are often found mixed together with the crude gold. The new process also can be used to extract gold from consumer electronic waste.
Current methods for gold recovery involve the use of highly poisonous cyanides, often leading to contamination of the environment. Nearly all gold-mining companies use this toxic gold leaching process to sequester the precious metal.
"The elimination of cyanide from the gold industry is of the utmost importance environmentally," said Sir Fraser Stoddart, the Board of Trustees Professor of Chemistry in the Weinberg College of Arts and Sciences. "We have replaced nasty reagents with a cheap, biologically friendly material derived from starch."
Sir Fraser's team discovered the process by accident, using simple test tube chemistry. A series of rigorous follow-up investigations provided evidence for the competitive strength of the new procedure.
The findings will be published May 14 in the online journal Nature Communications.
Zhichang Liu, a postdoctoral fellow in Stoddart's lab and first author of the paper, took two test tubes containing aqueous solutions—one of the starch-derived alpha-cyclodextrin, the other of a dissolved gold (Au) salt (called aurate)—and mixed them together in a beaker at room temperature.
Liu was trying to make an extended, three-dimensional cubic structure, which could be used to store gases and small molecules. Unexpectedly, he obtained needles, which formed rapidly upon mixing the two solutions.
"Initially, I was disappointed when my experiment didn't produce cubes, but when I saw the needles, I got excited," Liu said. "I wanted to learn more about the composition of these needles."
"Nature decided otherwise," said Stoddart, a senior author of the paper. "The needles, composed of straw-like bundles of supramolecular wires, emerged from the mixed solutions in less than a minute."
After discovering the needles, Liu screened six different complexes—cyclodextrins composed of rings of six (alpha), seven (beta) and eight (gamma) glucose units, each combined with aqueous solutions of potassium tetrabromoaurate (KAuBr4) or potassium tetrachloroaurate (KAuCl4).
He found that it was alpha-cyclodextrin, a cyclic starch fragment composed of six glucose units, that isolates gold best of all.
"Alpha-cyclodextrin is the gold medal winner," Stoddart said. "Zhichang stumbled on a piece of magic for isolating gold from anything in a green way."
Alkali metal salt waste from this new method is relatively environmentally benign, Stoddart said, while waste from conventional methods includes toxic cyanide salts and gases. The Northwestern procedure is also more efficient than current commercial processes.
The research—a prime example of serendipity at work, brought to fruition by contemporary fundamental science—is poised to find technological application. This basic science has been forged by the team into a practical labscale process for the isolation of gold from scrap alloys.
South Africa’s minerals research and development organisation, MINTEK, reports it has completed commissioning its water atomisation plant; a construction intended to research and develop atomisation technology for the precious and base metals industries.
Situated at MINTEK’s Randburg campus, the water atomisation plant will provide an effective means for the production of solid metal powder from 6 ton batches of molten metal.
According to Rodney Jones, a Specialist Consultant at MINTEK, many smelting processes that selectively recover metals, yield an alloy that is too malleable to be crushed or milled. However the downstream processing of the alloy often requires it to be in powder form and atomisation provides an effective means of producing metal powder from liquid metal.
The molten alloy is tapped into a ladle furnace where its temperature is controlled before it is discharged by using a slide-gate valve into a tundish that feeds the water atomiser.
Inside the atomiser, high-pressure jets impinge on the molten stream to break it down into fine particles, which can vary in size, depending on the alloy and the pressure of the jets.
The solidified particles are initially separated from the water by a magnetic separator, followed by a dewatering screw. The final drying of the powder takes place in a rotary kiln.
These powders are well suited for subsequent leaching operations where surface area is an important consideration. It is also suitable for pneumatic conveying and other material handling systems that require accurate feed rate control.
The atomiser plant was designed and built by MDM Engineering who sourced the atomisation technology from UK-based metals processing company Atomising Systems.
The new plant will initially be used for a two-year research and development project for Anglo American Platinum. Long duration demonstration programmes are particularly valuable in pyrometallurgical processes where many important engineering issues only surface (and can then be tackled) over much longer periods than typical pilot plant tests of a month or less.
The overall aim is to demonstrate the effectiveness and safety of the technology over the next two years.
After that, it should open up opportunities in various new areas, where ever malleable metal
alloys are required in powder form.
IN MINING YOUR SAFETY IS IMPORTANT, SO IS YOUR HEALTH.
What can miners do to improve their health?
Many suffer from common ailments such as allergies, eczema, gout as well as diabetes not to mention TB and Aids
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This 100% organic nutritional supplement with its carefully formulated blend of botanical oils serves as a powerful antiseptic, bacteria killer and virucide, which detoxifies and cleanses the blood, liver, kidneys, bladder and other vital organs, and boosts the immune system. Omega Herbal48 is gentle enough to do all of this without any side effects. Users around the world have reported relief from a wide range of conditions.
WORLD-FIRST FIELD TRIAL OF ‘IN-SITU’ GOLD EXTRACTION PROCESS
A new, environmentally friendly process developed by Australia’s CSIRO, to extract gold without mining, is to be field tested for the first time - with a South Australian gold deposit chosen as the test site.
The breakthrough in-situ process - which may reduce the need for conventional, expensive open-cut mining techniques – is being taken forward through a collaboration agreement between the CSIRO and ASX-listed minerals explorer, Minotaur Exploration Limited (ASX: MEP).
Minotaur announced today that a 15-month program of field trials to confirm the process concept will take place at its Tunkillia gold deposit in the Gawler Craton, south of Tarcoola.
“The process has the potential to revolutionise the way we normally mine near surface weathered (or ‘oxide’) gold deposits, while at the same time delivering potential massive cost savings for the owners of oxide gold resources,” Minotaur’s Managing Director, Mr Andrew Woskett, said.
He said the process is specifically designed to treat oxide gold occurrences, as distinct from sulphide (or ‘primary’) gold systems.
Successful demonstration of the process at the field scale could open up the potential for any similar oxide gold deposits to be brought into production at low capital and operating costs, compared to traditional mining and processing methods.
The process involves installation of a conventional groundwater recovery bore field and injection of an appropriate solution (“lixiviant”) into the host rock. The lixiviant dissolves the gold in the rock and the gold in solution travels through the rock mass to be recovered, to surface, via nearby extraction wells, as ‘pregnant’ solution.
This differs markedly from conventional heap leach gold operations which require the ore to be mined, crushed and stockpiled on surface (as ‘heaps’) prior to irrigation with a cyanide solution.
The CSIRO has developed a non-cyanide solution that, when injected into the host rock, is expected to cause minimal alteration to groundwater chemistry. The field trials will focus on determining key objectives: the transmission characteristics of the lixiviant through the host orebody; groundwater modification; gold recovery rates and; economic feasibility of the in-situ gold recovery process.
A range of environmentally acceptable lixiviants has been trialled in the laboratory by CSIRO, with promising results. Groundwater at the Tunkillia test site is restricted in distribution, is highly saline and is not fit for human or stock consumption. The tests are expected to demonstrate no material detrimental impact on the quality of the groundwater.
Significantly, the process negates the need for traditional reliance on cyanide in solution to liberate gold from ore, thereby minimising hazardous material consumption and potential site contamination.
It obviates the need for pre-stripping, drill and blast, open-cut mining, crushing and grinding circuits, cyanide leach systems, waste dumps and tailings dams.
Mr Woskett said the process is not dissimilar to the in-situ extraction methods successfully employed for over a decade by the uranium sector – a process, until now, not able to be applied to gold as a non-cyanide based solvent had not been previously identified.
“Successful results from the lixiviant leach trials are expected to show that operating and capital investment costs are substantially lower, and implementation timelines much shorter, than for conventional gold mining and processing installations,” Mr Woskett said.
“The in-situ recovery process could potentially make many low grade oxide gold deposits economic to extract.”
Andrew Woskett Minotaur Exploration (08) 8366 6000
Dr Tony Belperio Minotaur Exploration (08) 8366 6000 | 0417 829 942
Kevin Skinner Field Public Relations (08) 8234 9555 | 0414 822 631
New Technology - Redesigning the Drill
“We’re not just selling a product, but a concept which could change how mining is done around the world,” Mr Barrows of Peterstow Aquapower commented.
At its factory, the company produces a closed-loop hydraulic drill, which it claims will revolutionise mining across the world.
At present, most of SA’s deep-level gold and platinum mines use hand-held pneumatic drills to bore holes in the underground rock face. In pneumatic drills, compressed air drives the drill bit. Explosives are then inserted into the holes to blast the rock.
“If you go underground, it’s like stepping into the Victorian era. If you had cryogenically frozen a miner from 100 years ago, the only difference would be the cellphone,” says Douglas Barrows, Peterstow founder and chairman.
The problem with pneumatic drilling is that it is very energy-and water-intensive. A compressor – which compacts the air for the drill – is on the surface, which can be thousands of meters above the actual drilling.
It is “very inefficient” mainly because of leaks in the pipes before it gets to the drill, according to Declan Vogt of the CSIR’s Center for Mining Innovation. “Of the electrical energy used, only 1% gets used in the drills,” he says.
Ian Cockerill, former CE of Gold Fields and a Peterstow board member, says: “The installed energy capacity at the average large mine is around 250MW, and something like 30% of that consumption is from compressors. If you can eliminate that energy consumption on half-dozen mines that saves enough energy to power a town the size of Port Elizabeth.”
Moreover, giant tanks of oil are attached to the compressor. This is to facilitate oil-mist lubrication for the machinery. This is part of the acid mine drainage problem and pollutes drinking water, Mr Barrow says.
“It was a crazy idea. I realised the future of the world (and mining) was not oil, but water.”
Mr Barrows developed the idea for the drill in the mid-1990s, but the technology suite did not exist at the time. “They’ve now completed the jigsaw puzzle.”
The Peterstow drill employs a patented closed-loop water hydraulic system in conjunction with modular power packs, which are taken underground.
The design dramatically reduces water and electricity usage.
It also decreases the chance of flooding, meaning that mines do not have to install and pay for additional facilities to pump water back to the surface.
The global mining industry is a big user of electricity. South African mining houses, in particular, are under pressure to cut the electricity consumption. Acid mine drainage – polluted water from mining areas – has found its way on to the national agenda.
“We can cut electricity consumption by up to 25%, and water usage by as much as 855, but the saving depends on each mining case,” Mr Barrows says.
Alan Barrows, Douglas’s son and Peterstow director, says the new leaders of mining houses are “more modern and forward thinking. We are in advanced negotiation with a number of South African mines.”
Douglas Barrows says: “There are about 34 trials and evaluations underground at this moment.”
The factory in Swaziland produces the drills and power packs – which come in 7,5kW and 15kW units – as well as road-breakers for construction. However, Peterstow has its eye on expansion, in which Alan Barrows envisions the factory producing 4 000-5 000 drills a month, from the current 100. Peterstow drills retail for about $18,5m for 1000 drills.
However, mines face a quandary as, on the one hand, the pneumatic drill infrastructure exists down the shafts but, on the other hand, the energy and water inefficiencies push up their costs.
Mr Vogt says: “I like the Peterstow technology. Redesigning drills from scratch and powering them with water has resulted in a superior drill, but you can’t predict worker preference.
“Managing the change process will dictate whether they (Peterstow) succeeds
Source: Business Day
Rio Tinto announces new global Centre for Underground Mine Construction in Canada
Rio Tinto has announced a key strategic partnership in Canada, teaming with world leading researchers to create the Rio Tinto Centre for Underground Mine Construction.
The new Centre will be based at the Centre for Excellence in Mining Innovation (CEMI) in Sudbury, Ontario, and will focus on innovative rapid mine construction and ground control for mining at depth. Rio Tinto is investing C$10 million over five years in the centre, completing a suite of five global long term Rio Tinto research centres around the world.
The work with CEMI will assist Rio Tinto’s development of new excavation systems through The Mine of the Future™ programme, focusing on significantly improving the construction and operation of underground mines.
As part of this programme, Rio Tinto will conduct a full scale performance verification trial in 2012 at Northparkes’ copper and gold mine in New South Wales, Australia, as the first of three new underground excavation systems.
Rio Tinto Head of Innovation, John McGagh, said: “In order to satisfy the global demand for minerals we will need to go deeper to access new resources. By partnering with CEMI, Rio Tinto is supporting research into high speed underground mine construction.
“This collaboration is in keeping with our long term commitment to innovation. It’s part of our strategy to collect the world’s experts and develop mutually beneficial partnerships to develop technologies which address the future requirements of Rio Tinto. Put simply, there is no other mining operation in the world attempting to take the approach that we are on this scale.”
CEMI President/CEO Doctor Peter K Kaiser said Rio Tinto’s support would enable CEMI to collaborate with recognised researchers on ground control and machine performance issues.
“With test sites, possibly on three continents, it will be of strategic importance to strengthen collaborations with expertise beyond our boundaries,” Dr Kaiser said.
“In collaboration with Rio Tinto, CEMI will be able to expand its research and development programmes and increase its global reach.”
Rio Tinto General Manager Underground Innovation Dr Fred Delabbio said: “Our partnership with CEMI provides an opportunity to combine experts from the civil and mining industries. The Centre’s research into high speed underground mine construction will include implementation of mechanised tunnelling and shaft sinking systems and CEMI will assist in the development of innovative support systems and in minimising the risks for such technologies.”
Key areas that CEMI will work on include:
• developing and designing innovative support methods for different excavation systems;
• establishing reliable predictions of rock behaviour to ensure effective construction technologies are selected and utilised;
• advanced rock mass characterisation technologies;
• performance of mechanical rock excavation based systems from an equipment and ground management perspective;
• pillar design and underground excavation stability projects such as rock fracture modelling.
More Efficient Analysis
The Anglo Platinum Group recently found it necessary to implement more efficient ways to analyse its geological assay data, and turned to Octoplus and the SAS JMP data visualisation tool.
Anglo Platinum drills between 600km and 700 km of exploration boreholes a year, with samples taken at regular intervals across reef intersections. These samples are used to evaluate the potential of future mining at various sites around the Bushveld Complex. Each sample is analysed at one of a number of a laboratories and checked for quality assurance and quality control (QAQC).
Anglo Platinum turned to Octoplus as a technology partner with the SAS JMP data visualisation tool to help it overcome the problems experienced in its old system.
The first application of the JMP tool provided Anglo Platinum with a sample tool based on a number of primitive scripts, which covered a very basic set of calculations such as a single outliner method, precision and basic statistical parameters. While all the results could be recorded in a journal file, it was not compulsory to do so to move to the next script. This meant it was possible to forget to journal, in which case one had to begin again.
Octoplus uses a customized set of scripts and tools, all grouped under an Angloplat button on the toolbar. With JMP every action is menu based and involves four separate components: evaluation of assay data; evaluation of blanks and standards; a set of useful tools and lookup tables (which can be edited by the user); and an extraction utility that allows a user to extract data from SQL based databases.
The menu system also provides an audit trail with the evaluation facility recording every action that a user makes and storing these in a separate journal file.
A user-friendly interface allows a user to extract data directly from the Anglo database into JMP. JMP can handle an almost limitless number of records.
JMP is a data visualisation and statistical discovery software tool that combines the use of graphical capabilities, the ability to manage virtually unlimited volumes of data and seamless integration with SAS Analytics tools. Traditionally used by scientists and engineers, JMP provides business users with the ability to replace static charts with motion-enabled, interactive plots that uncover hidden trends and predict the future. Through graphical data querying, enhanced script editors and project collaboration tools, data discovery is made more comprehensive.
Leppan Beech & Webber Wentzel to Combine
Leppan Beech Inc.'s multi-disciplinary Mining Team will be joining Webber Wentzel effective 1 March 2010. The combination of the LBI Mining Team with Webber Wentzel's Mining, Natural Resources and Energy Practice Group creates a team with unmatched capacity and expertise in the mining field in South Africa and Africa.
Together, we are uniquely positioned to provide mining clients with the most comprehensive offerings including commercial, mining M&A, health and safety, environmental, mining and minerals regulatory, all employment law aspects related to the mining industry and land work.
The combined team will operate under the Webber Wentzel brand and be headquartered in Webber Wentzel's Johannesburg office at 10 Fricker Road in Illovo. LBI's Eugene Phajane will continue to operate from the Rustenburg office.
The Role of Simulators in Mining
As far back as 1929, Edwin Link developed a system to simulate the experience of flying an aircraft while sitting in a replica cockpit in a training centre. About thirty years later, after a modest beginning, mines started to introduce simulators mainly for driver and safety training.
There was a period when on-the-job training was regarded as the only practical way of introducing mining recruits who completed basic training to the real work situation. On-the-job training is still vitally important but the length of training periods, and costs, can be reduced considerably by using mining simulators as a system to replicate elements of mining operations.
Today, simulators are used to teach trainee operators how to operate high capital cost machinery such as continuous miners, excavators, draglines, and haul trucks.
What is meant by simulation?
Simulation is a computer program that imitates a physical process or object by causing the computer to respond mathematically to data as though it is the process or the object itself.
Simulation software is widely used to design equipment so that the final product will be as close to design specifications as possible. In theory, any phenomenon that can be reduced to data and equations can be simulated on a computer. In practice, however, many variables are at work in natural phenomena and this can make simulation extremely difficult.
Prior to introducing new equipment or machines to the mines stringent tests are carried out by mining equipment manufacturers. In some cases the manufacturers will employ non-destructive testing and in other instances units will be tested to destruction. Published test reports often reveal that simulation played a part during the testing exercise.
Advanced computer programs can simulate many of the processes and operations that are at work on mines. It can be used in mine planning, safety training, laboratories, geophysical research, seismic event analysis, and also to test new theories. It can be used when re-training is necessary.
Simulator-trained personnel can play an important part in getting projects such as mineral or chemical processing plants, refineries, factories and complicated structures off on a safe and error-free start.
Last year Science Daily published information about a mine roof simulator, the only mine roof simulator of its kind at the time that was designed to test mine support systems and structures to prevent the roof from collapsing. Using up to 1 500 tons of vertical force and 800 tons of horizontal force, the simulator offered researchers an opportunity to test integrity, stability and performance under simultaneous loads in the vertical and horizontal directions.
This is an important step forward in dealing with falls of ground. Not only is there a threat from the sheer weight of the ground above, but also from the many layers of shifting rock. The machine enables engineers to monitor the pressure and movement to see how much a structure can withstand.
With a machine like this a dangerous job is made safer. In future, it may not be necessary to take supports underground for testing. Miners are exposed to danger when experimental supports or any newly introduced piece of equipment do not work.
In another development, seismic waves from massive rockfalls underground or collapsing mines can now be distinguished from other seismic events. If a seismic event is registered in a mining area in South Africa, scientists want to know whether it was a natural occurrence or caused by mining operations.
A useful tool for gaining insight into the source mechanism of rockbursts and control of accompanying damage is …simulation.
Sorters Reduce Mining Costs and Increase Profits
At a recent mining convention in Las Vegas, Matthias Moritz, MD of Commodas Mining GmbH in Germany, delivered a strong and positive message to delegates: sensor-based sorting machines have impacted on the mining industry to the extent that they are fast replacing the traditional, high cost methods of milling and expensive metallurgical processes. Tough economic times have led to a steady decrease in raw material prices, particularly in the mining industry. Mines using electronic sorters have reported a significant reduction in mining costs and an increase in profits. Once on stream, the benefits are almost immediately reflected in the bottom line.
“The advantages of eliminating waste and sub-economical ore from plant feed are convincing,” commented Professor Wotruba of Aachen University in Germany. He went on to say that traditional pre-concentration methods for plant feed have limited applications, whereas sensor-sorting can separate material which is impossible to treat by traditional methods. “Sorters can work, where these methods fail,” he said.
Using high speed, high tonnage sorting machines has markedly reduced beneficiation costs. The new generation of sorting machines are so sophisticated and versatile that a number of loss-making operations have been able to maintain production by mining and sorting low grade ore bodies, extending the life of the mine and preventing closure.
The current financial downturn has forced mines to lower operational expenditure (Opex) and increase output to ensure the survival of the mine.
Commodas sensor-based sorting machines detect and separate the valuable ore fraction from barren residue at high speed and at low cost, with close to one hundred percent accuracy. Increasingly, this technology is also being used in other industries, such recycling and dump reclamation.
The effectiveness of advanced process and separation technology is clearly evident at a limestone quarry in Finland, where over 220 000 tonnes of valuable white limestone was extracted from the waste rock dump, thanks to the use of optical sorting technology. This investment in sorting not only paid for itself, but also allowed the limestone plant to once again operate profitably.
According to Rosemary Falcon, Director of the Fossil Fuel Foundation and professor in the School of Chemical and Metallurgical Engineering at the University of the Witwatersrand, Johannesburg, the application of X-ray sorting on dry coal has solved a long-standing problem in the coal industry. “These sorters identify and separate torbanite from coal,” she said. “The typical method is to separate coal from the host rock using heavy media concentration with the torbanite fraction included. Since this is a mineral rich clay with a high proportion of fossil algae, and is a valuable source of high quality coal, bitumen and oil, the X-ray sorter has made an enormous difference in separating torbanite from the lower grade coal.”
Sensor-sorters represent an investment in the future, with long term advantages over traditional processes that are slow and inefficient, resulting in poor recovery rates. Updated sorting technology ensures that only the valuable mineral fraction is retained for further processing and waste or barren material discarded. Waste is removed on site before milling; pre-concentration can take place on surface or underground; and chemical usage is considerably reduced. Fast processing results in a quick return on investment, consequently, net present value is increased.
With sophisticated detection, process separation and ejection systems, sorters use a number of intelligent detection criteria to identify ore and mineral characteristics, such as colour, atomic density, transparency and conductivity. These include optical and colour recognition, X-ray transmissions, radiometry, near-infrared, fluorescence, conductivity and magnetic systems. This technology is successfully applied to a wide variety of minerals, metals and gemstones.
A focused approach to research and development guarantees ongoing optimisation of systems producing reliable, state-of-the-art machines that are at the forefront of sorting technology. Fast throughput rates, low maintenance costs and a proven global track record attest to the rising demand for sensor-based sorting machines not only in the mining industry, but also in commercial and industrial operations.
Sensor-based sorters not only increase profit by improving yield and recovery, but reduce emissions and energy consumption, thus they are environmentally friendly.
Commodas Inc. Hannie Reidel
Box 81097 Commodas (Pty) Ltd
Toronto Box 787104
Ontario M5J2G4 Sandton 2146
Canada Gauteng South Africa
Tel: +1 416 214 7737
Tel: +27 (0)11 666-4781
Fax: +1 416 369 0515 Fax: +27 (0)11 666-4647
Compact but Powerful Bead Breakers Save Time while Enhancing Safety when Changing Big Tyres
High pressure hydraulic bead breakers protect staff and machinery by dispensing with heavy, clumsy, labour-intensive equipment and replacing it with precisely applied high force from easily handled tools.
Compact but powerful 700 bar bead breakers from Enerpac can also save a lot of time during routine workshop maintenance and on-site repair operations that involve changing tyres on large trucks, tractors and implements.
The 700 bar EBB400 (45kN) and EBB180 (140kN) bead breakers are designed for heavy vehicles and implements used in the construction, civil engineering, farming, heavy industrial, mining, primary industry, quarrying and transport industries.
Weighing 15kg, the EBB400 Combi Bead Breaker handles two and three-piece, 2-5-10 hole budd, 7.50x16’s and all tubeless truck and farm tyres and rims. Simple to operate without screws, bolts or attachments, the breaker assembly clamps hydraulically to all rims in seconds and breaks beads precisely with up to 45kN (5 Ton) of force. Uses of the EBB400 include tractors, trucks, graders and implement tyres.
The EBB180 Giant Tyre/Earth Mover Bead Breaker, weighing just 14kg, is designed for use on off-road vehicles using five-piece rims of 25”- 51” in with pry bar head loosening pockets. Its 140kN (15.5 Ton) hydraulic cylinder has a long, 100mm, stroke for tough-to-break tyre beads.
Both bead breakers are compatible with some of Enerpac’s most commonly used pumps throughout Australia and New Zealand, including the PATG1102N air/hydraulic pump, PUJ1200E electric/hydraulic pump, and P392 hand pump, all with HC series hoses.
They are also highly compatible with the new generation XVARI ® XA air-over-hydraulic foot pumps being introduced by Enerpac to enable finer and safer control of tasks while completing jobs up to twice as quickly as conventional pumps.
Enerpac says the 700 bar XVARI ® XA features tremendously high oil flow, with its rotating air motor and rotating two-stage pump element giving hydraulic delivery up to 50 per cent higher than conventional pumps with linear motor and single piston.
Enerpac has been established in Australia and New Zealand as a major supplier of 700 bar hydraulic equipment for 50 years. Its ranges of lifting, pumping and professional bolting technologies are used extensively throughout industries including building and construction, civil and process engineering, energy, infrastructure, manufacturing, mining, resource development, primary production, safety, transport and water and wastewater.
For more information e-mail email@example.com.
Have we squandered our opportunities to create a world-class mining museum in South Africa?
Gerhard von Ketelhodt, author of “The Golden Crown of Johannesburg”, is on a four month tour through Europe and Canada. He will be visiting mining museums in Germany, Holland and Canada. Writing about some of the museums he has visited so far he expressed his disappointment that the greatest gold mining country in world and the “City of Gold”, Johannesburg, do not have a world-class mining museum.
During a visit to a modern museum in Weissenberg, Bavaria, he was surprised to find a substantial section of the museum devoted to the discovery of gold on the Witwatersrand. “They seem to have a better appreciation of the significance of that great discovery than we have in South Africa”, he wrote.
Von Ketelhodt, reporting on visits to other museums in Europe and Canada, found well-managed and well-equipped museums in mining towns. He was fascinated by the way modern multimedia and display techniques were employed to ensure that a visit to the museum would be a memorable learning experience.
If we were to follow the example of overseas countries where almost every mining town takes pride in its mining museum, we should encourage local mining towns to make the most of what they have.
There are mining towns in South Africa that jealously preserve their own collections in small museums. Some have outdoor museums. In some cases small towns are no longer able to protect outdoor exhibits against the elements due to lack of funds. The management of small town museums are often placed under the care or supervision of civic-minded individuals such as librarians, owners of curio shops or tourism information centre personnel.
Small town mining museums
If South Africa had a world-class museum, and if private collectors, small towns, mining companies, and cultural and educational institutions could be persuaded to contribute heritage material to a national repository of mining heritage material we could have one of the largest mining museums in the world in a central location.
As to the question where such a museum could be situated, one has to ask: “What better place than the very site where the Witwatersrand goldfields were discovered or a suitable site close to the Johannesburg mining district where the major players in the mining industry have their headquarters?” Is such a site available? I know there are a few historical sites that may be suitable.
I also happen to know that there are numerous influential people in the country who are passionate about preserving our gold mining heritage.
Destruction of relics
It is a sad fact that much of what could have stood as monuments and reminders of the greatest gold mining achievements in the world have been demolished or vandalised. When old mines closed down, treasure hunters moved in and grabbed whatever they considered to be collectors’ items: documents, photographs, maps, instruments, books, trophies, archival material, artifacts, thousands of carbide lamps, and other heritage objects.
The battle to save the number 2 Shaft headgear of Crown Mines, a magnificent landmark, was lost long ago. The headgear was dismantled. The number 5 Shaft that was used to hoist most of the gold–bearing ore produced by Crown Mines, the ‘Golden Crown” of Johannesburg’, was dismantled a few months ago. What we have lost through neglect, poor maintenance of heritage objects and sheer ignorance of restoration techniques cannot be calculated in monetary terms.
What used to be called a gold mining museum, Gold Reef City, is now a theme park. There is still a semblance of a museum but most of the local visitors, show little interest in the displays. They go there for ‘thrills and spills’ at the theme park.
In the absence of strict security measures in the past, numerous valuable objects have been stolen from the museum, the main culprits being museum personnel.
The decay started when control of the museum passed from the Chamber of Mines of South Africa to private entrepreneurs. The museum lost its character when the new owners decided to develop a theme park. Noisy theme park structures were placed right next to exhibits of magnificent hundred year old mining machines.
A remarkable model
One of the outstanding exhibits was an 18 metre long model of the CMR mine, a masterpiece of modelmaking that was a major attraction at the Empire Exhibition in 1936. That year marked the Jubilee or the fiftieth anniversary of the proclamation of the Witwatersrand Gold Fields and the foundation of Johannesburg. The model was one of the first items to be on display at the Gold Reef City museum.
For reasons not known, the new owners decided to dismantle the masterpiece of modelmaking which was complete with fine miniature hand-made replicas of mining and mineral processing equipment. The broken sections, damaged beyond repair, were dumped in a store room.
Did anyone think of taking photographs section by section with a view to at least have a record of the model before it was removed? Where are the original drawings of the model? Did they ‘do away’ with the model because no one could be found who knew how to maintain it?
Other sections of the museum have also been removed.
The replicated houses at Gold Reef City
In the mid-seventies Ken Birch, former chief architect of Anglo American, and I were engaged in recording details of historical buildings on the East, Central and West Witwatersrand in preparation for the erection of replicated houses and old mine structures at the Crown Mines’ number 14 shaft, the site where Gold Reef City museum was to be located.
We started at Springs some 60 km east of Johannesburg taking photographs and making sketches and ended at Randfontein, 40 km west of Johannesburg. There were photographs of ordinary houses designed by Sir Herbert Baker and grand, but neglected homes, formerly occupied by mine magnates and mine managers.
When I went to the museum about two years ago to find out what happened to the hundreds of photographs and Ken Birch’s architectural drawings I was told that it had probably been disposed of during clean-up operations.
Gold Reef City could have been our world-class gold mining museum. But because of a lack of vision and a poor understanding on the part of persons in control of the need to preserve our heritage wealth, we lost the ideal site for our dreamed-of museum.
In the past I have expressed the view that in just a few years it would be difficult to procure well-preserved relics and artefacts to equip a mine museum. I am in touch with several people who are so passionate about preserving what is still available that they are seriously engaged in discussions about the feasibility of developing a mining heritage centre, a training facility, and a mining research and development institution within a mining precinct.
A world-class establishment
The museum would have to be so well designed, and so inspiring that the community and tourists would want to visit again and again. People are no longer interested in staring at static museum pieces in glass cases. So, right from the start it would have to be (sorry, I have to use that word again) a world-class establishment.
In certain European countries the word “museum” is anathema. This is because there is a connotation with static and dull displays of historical objects. For the sake of brevity I have used the word museum while in the back of my mind I visualised a large area with enough space for creation of a gold mining heritage preservation centre, and a cultural and educational precinct. It would have to be a vibrant community centre of which the community would be proud.
The actual ‘museum’ would be a centre of learning, animated, entertaining, alive and engaging. Multimedia presentations and interactive stations, animated models and intelligent self-guiding systems would have to be some of the features of the entire set-up.
I am beginning to wonder, though, whether we have not squandered our opportunities to create the greatest gold mining museum in the world. Fears that the economic woes of countries abroad would sooner or later blow across to South Africa, could put a damper on further discussions. As eager as I am to see the fulfilment of the enthusiasts’ dream, I have a feeling that the climate for such an ambitious project may not be right.
It is going to be extremely difficult to persuade the government, the city council, mining companies and philanthropists to support such a venture in the present economic climate.
Yes, it is true that up to now South Africa has experienced unprecedented economic growth but there are signs that the country will come face-to-face with the same woes that led to the crash of world markets. Museums are not profit-making establishments. So there is nothing in it for investors and, besides, investor confidence in South Africa is at an extremely low ebb.
Can something be done to safeguard our heritage?
Do the foregoing observations mean that there is nothing that can be done to celebrate 120 years of the greatest mining achievements the world has ever witnessed? Is it not a shame that the greatest gold mining country in the world and the ‘City of Gold’, Johannesburg does not have a true mining museum?
People, mining people, anthropologists, geologists, archaeologists in particular, are travelling halfway around the world in the expectation that there will be a central complex where they can learn as much as possible about the mining miracle that has taken place here at the southern tip of Africa.
Developing a virtual museum
When some of the of great museums of the world, like the Guggenheim Museum in New York, for example, realised that millions of people will never be in a position to visit their magnificent establishments they decided to take the contents of their museums to the people. They created virtual museums and made it possible for people worldwide to view exhibits on the internet. Virtual museums provide ways to capture the content of a real museum in a digital (electronic) form and to make it universally available.
A virtual gold mining museum
Since it may take years before we will see a gold mining museum, is there someone interested in museology, someone with a practical mining background who wouId take the initiative to create a cyber museum, that is, a virtual museum with gold and gold mining in South Africa as a central theme?
I am pleased to mention that, under construction right now, is my website www.goldencrownminingmuseum.co.za. When completed, the cyber museum will contain my entire private collection of mining photographs, documents, papers, and stories that I have collected over a period of 40 years. It will be accessible to people on all continents to view on the internet.
A future stage of development of the Golden Crown Mining Museum would be virtual online multimedia guided tours to operating mines and an amazing volume of information about past and present mining methods.
The educational content of the Golden Crown Mining Museum will probably the most attractive feature of the website. Regular features will be contributions by anthropologists, archaeologists, geologists etc. presented in an easily digested style and a format conducive to learning. Most of the presentations will be interactive and suitable for instruction of learners.
I have scoured, and will continue scouring the archives of mining companies that have been operating in South Africa since the discovery of gold on the Witwatersrand in 1886. While I will be spending much time on populating the virtual museum website I do not intend losing sight of the desirability of having a world-class mining museum adjacent to the Johannesburg central mining district which is presently undergoing a facelift.
This will not be a one man show. I will be supported by a small team of researchers, photographers and multimedia specialists.
Under lock and key
I have communicated with a few other custodians of heritage material and have been given permission to photograph and write about some of the treasures that are being kept securely under lock and key. While it is commendable that such treasures are being preserved for future generations, something must be done to
expose it to the present generation. Now it can be done without risk of damage or loss, by medium of 3D digitization and virtual exhibits.
The cost of developing the Golden Crown virtual mining museum will not be inconsiderable. Although it is not intended to be a profit-making vehicle, funds will be needed to cover developmental and production costs. Several ways of how this could be done have been suggested and are being considered.
Professional persons representing some mining-related disciplines who share my passion for the creation of a virtual repository of mining heritage treasures have offered to contribute, free of charge, authoritative material to enhance the content of www.goldencrownminingmuseum.co.za
Following the publication of this article, companies and manufacturers of mining equipment with a long histories of serving the mining industry will be requested to allow me and members of my team to visit their archives so that we can record items that may have been hidden from the public eye for decades.
Readers interested in cooperating with us in building our virtual museum can communicate with me on firstname.lastname@example.org or by calling 083 173 5907.
Getting IT right at the mining workface
ICT systems need to be extended to operations to improve performance and enhance efficiencies
The mining industry in South Africa has played an important role in our economy. Initially, a fairly simple system was used to extract raw minerals such as gold, with a large emphasis on labour. However, this industry has since evolved into a giant and the business - which includes operations, finance, HR, stock and more - has become multi-facetted. Information Technology (IT) has been a key enabler but it's not yet the 'silver bullet' it promised to be.
Says Cassim Parak, CEO of e.com institute, a business solutions provider: "There have been a number of significant changes over the years in the mining industry, affecting the way planning is done, how the business is administered and people are managed. Accurate and timeous information that better informs decision making at an operational level is essential if operational performance and efficiencies are to be enhanced and these organisations are to remain competitive."
While the big mining companies are all in the process of converting to ERP for financials, HR and supply chain management, there is no suite that is specifically designed to cater for this industry. Thus operations, safety and some risk systems are still run separately or done manually. Says Parak: "BI tools and methodologies are being used to integrate data. Data is imported to a data warehouse to generate reports and build and populate dashboards. This may satisfy the need of top management. However, to keep a finger on the pulse of business and improve performance, more accurate and more timeous integrated information is needed."
In the world of underground mining, the 'factory' is below the surface of the earth, but with a traditional focus on management there has been little in the way of investment in IT infrastructure at the workface. Parak explains, "This has left an information gap. With no real time information to support decision making at this level, IT systems have become a runaway train, exerting undue influence on business and operational decisions. In a nutshell - mine management just doesn't have the full picture. Top down control needs to be complemented by accurate and timeous bottom up information."
A change in the way business is conducted also points to the need for new business and information support systems. Where previously planning was only done at a high level, mining executives now have to dig deep into their resources and data base to gain access to not only the geological information and historical production information, but the knowledge and skills necessary to properly manage their most precious asset, their ore resources. Added to this, the way people work and how they are managed has changed and corporate governance and compliance requirements are exponentially more stringent.
"Maintenance of underground equipment, resource management and operational planning are key instances where IT systems fall short at an operational level," Parak notes. "Planned maintenance is essential but so is a system that manages unexpected equipment breakdowns. Mines need to know not only what to do in terms of standard maintenance but, to optimise daily operations, they need to know what has broken down where and be able to deal with it timeously. At present, an outgoing shift manager will pass on this information by word of mouth to the incoming team, which may only report the problem (often inaccurately) 24 hours later."
The same issue arises with regard to resources. Explains Parak: "While HR systems contain all the necessary details to ensure staff are paid accurately, resource management functionality is limited. If someone takes ill, a verbal report may only reach the resourcing officer two days later. It takes another two days to find a replacement. Meantime, the shift is short of a full complement of people. Time is lost and production quotas suffer.
Parak adds, "Accurate planning means getting the right equipment to the right point with the right number of resources and skills mix to meet task requirements. This requires a solution that allows information to be captured as and when needed - one that will update management systems timeously to enable accurate daily planning."
Financial systems also do not cater for operations. In the last couple of years, compliance issues have driven the adoption of better financial systems. Financial accuracy is a must for reports and the validity of data has been a focus. Notes Parak: "For management, the goal has been to reach a point where they don't challenge the accuracy of the information contained in a report, they challenge the problem it represents. However, a key weakness is that financial reports still drive the organisational structure and investment decisions. Without an understanding of underlying impacts and the root causes of business performance, this leaves the IT system to drive the business. A crucial shortcoming is that financial systems are built for financial professionals, not operational staff."
Underground operations will look at processes and the cost implications of the processes. Process and activity costs are normally influenced by the depth, temperature, travelling distance and the distance to the stope face. The deeper or the further you go into the mine, the higher the costs.
Says Parak: "To accurately determine and manage costs, an operations manager will thus have to consider the area in which mining is taking place, the activities happening at any point, who is responsible for costs, and the type of costs (labour, stores, etc) incurred. While most financial systems will cater for one or two of these items, none cater for all. There is thus little true transparency. Since few mines have access to this information, averages are applied - which makes it a hit and miss affair."
ICT cannot be positioned as a business driver; it must be an enabler of the mining business, Parak reiterates. "A better approach is to identify the 'real' business requirement and find a solution that meets that requirement, ultimately improving the performance of the organisation."
As in any organisation where information begins to be applied to the advantage of the business rather than being used as a tool for individual advancement, a culture change is necessary. Advises Parak: "Everyone in the organisation - and especially those that have not previously had access to information that can assist decision making - needs to become more aware of the value of information. With broader access to more accurate information, the experiential knowledge of individuals can be better leveraged and applied to the benefit of the business. Support for this change needs to come from the top down, however, the right systems and data structures need to be put in place."
Building such a system could take as little as nine months if data structures are in place and data is accurate, Parak suggests. "However, if the business needs to start from scratch - identifying available information, cleansing it and building a system that delivers the right information at the right time to the right people - this process could take as long as five years. While this represents a considerable investment, the benefits can be enormous, not only improving performance at all levels, but increasing the sustainability and agility of the organisation."
A beautiful balancing act as Synchronous Lifter
One of the world’s most advanced heavy lifting systems has been deployed in Australia to maximise safety and precision during maintenance of a huge dredger at the largest coal mine in the Southern Hemisphere.
The PLC controlled Enerpac Synchronous Lifting system was used by Hydraulic and Pneumatic Pty Ltd of Morwell in conjunction with Plant Performance Group Pty Ltd to enhance precision and safety while monitoring the 2200-ton load’s centre of gravity during the lift on Dredger 16 at Loy Yang Power.
Dredger 16 is longer than the MCG (200 metres), as high as a 16-storey building (55 metres) and has a slew ring bearing 15,2 metres in diameter containing 177 balls of 200mm diameter each weighing 32kg. It weighs a total of more than 5.000 tons and can remove 60.000 tons of overburden a day.
This 5000 tons coal mine dredger is more than 200 metres long and 55 metres high.
The successful lifting and balancing of its huge superstructure illustrates the versatility of the Synchronous Lift system for major industrial and civil engineering tasks, including manufactured structures, buildings, bridges, oil platforms, ships, turbines, generators, mills, mining equipment and heavy but delicate computerised/electrical equipment, says Enerpac.
The Synchronous Lifting technology chosen for the task of hoisting Dredger 16’s superstructure to inspect and refurbish the giant machine’s slewing ball race uses digital synchronisation control accurate to within a 1 millimetre between leading and lagging lifting points. Accuracies are available down to 0,1mm.
Dredger 16 can remove 60.000 tons of overburden a day.
The delicate job of carrying out the lift with maximum safety and minimum downtime was carried out with the assistance of a team led by Shift Supervisor Mr David Little of Silcar, which is an asset manager and provider of maintenance services for technically complex assets.
The task involved two-stage lifting and lowering over 250mm, with the Enerpac Synchronous system governing six 630 ton hydraulic cylinders used in pairs at three lift points.
Project Manager Mr Tom Lamin of Plant Performance Engineering acting for Loy Yang Power, said the lift proceeded smoothly, with the hoisting being undertaken on May 7 and lowering on May 13. The huge task was facilitated by the accuracy and fluency of the synchronous lift operation, and the real-time centre of gravity display.
Dredger 16 is as high as a 16-storey building (55 metres).
Hydraulic and Pneumatic Sales Manager Mr Robert Lewis said the job required thorough planning to maximise safety and minimise downtime for a client operating the largest open cut coal mine in the southern hemisphere. Loy Yang operates 24 hours a day mining more than 30 million tonnes a year of the brown coal that provides more than half of the State’s electricity needs.
“Everything is on a large scale – the slewing ring is huge and the superstructure above it is bigger than many ships’, so the job had to be done with incredible care and precision to meet the client’s top world class standards of safety.”
The Synchronous Lifting system used by Hydraulics and Pneumatic was an eight-point model that can be used with multiple cylinders ranging from 10-1000 tonnes capacity each. Larger models feature up to 64 control points. The hydraulic technology involved is the same type chosen to maximise safety on some of the world’s most precise lifts, ranging from Ariane rocket launch pads and oil drilling platforms in Europe’s North Sea, to splitting coal shovels and building and weighing wharves and infrastructure in Australia.
“In addition to being precise and giving us the centre-of-gravity accuracy we needed, the technology had to be able to function flawlessly in a harsh environment, with coal dust blowing around the power unit.
“We needed to be assured – and this turned out to be exactly the case – that the technology package developed in conjunction with Enerpac would operate in total safety and reliability.”
Synchronous lifting and lowering of the 5000 tons dredger using six 630 tons hydraulic cylinders, used in pairs at three lift points.
Controlled hydraulic movement
Enerpac Engineer Ray Paasila said safety was built into the synchronous system – “During lifting in automatic mode, the software meticulously follows each lifting point and each cylinder. The software also constantly monitors which lifting points are in the highest and lowest positions and whether these are still within the set tolerances. If a correction has to be applied, the 2/2 movement valve opens briefly and the relevant (lowest) cylinder receives a short hydraulic impulse, instantly followed by a new reading. This correction process is so fast that the relays that control the valves give the effect of perfect switches.
The dredger has a slew ring bearing 15,2 metres in diameter containing 177 balls of 200mm diameter each weighing 32kg.
“The course of the lifting process can be followed on screen (per lifting point). The software also contains an extra control function, by which the system can temporarily be stopped and manually corrected. Emergency stops also built into the system. If something goes wrong, the system will stop automatically and block all points of support.
“In addition to time saving and the exceptionally accurate and virtually stress-free movement of an object, the advantages of Synchronous Lifting include its ability to record and document the entire repositioning process. All the values are stored in the control systems memory for later use. With satisfactory progression of the procedure, this provides both the contractor and the client with a clear guarantee that excessively high stresses have not occurred.”
Chipped slew ball of 32kg and 200 mm diameter from the the giant machine’s slewing ball race.
Enerpac synchronous lifting technology has been used in Australia for integrated solutions involving ultra-precision civil, mechanical, industrial and maintenance engineering tasks, including the splitting of a dragline at Curragh coal for maintenance and during vital stages of the ongoing .2 billion expansion of the Dalrymple Bay Coal Terminal near Mackay, where it was used to lift and weigh 80-tonne sections of wharf.
“In addition to time saving and the exceptionally accurate and virtually stress-free movement of an object, the advantages of Synchronous Lifting include its ability to record and document the entire repositioning process.
“All the values are stored in the control systems memory for later use. With satisfactory progression of the procedure, this provides both the contractor and the client with a clear guarantee that excessively high stresses have not occurred.”
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CONCARGO NOW MEMBER OF THE HEAVY WEIGHTS
Concargo, experts in Supply Chain Management activities, have successfully qualified in becoming the first African member of “The Heavy Lift Group” (THLG), a group of specialist heavy transport companies that combine to offer the best expertise and service in Abnormal Out-of-Gauge Project Cargo according to customer needs. This means that Concargo will facilitate all heavy lift transport and overland, outsize cargo movements, mobile crane operations, rigging, machinery installation, and large scale project forwarding into Africa on behalf of THLG’s members.
THLG (www.theheavyliftgroup.com) was founded in 1987 by a number of West European Heavy Lift Operators in anticipation of the single European Market, and has since expanded into a worldwide group having members in the U.S.A. Latin America, the CIS, the Middle East, Asia and now South Africa and into the rest of Africa by sea, air and road.
Furthermore Concargo Sub-Saharan Africa in Zambia has been accepted as a member of Worldwide Project Consortium (WWPC) (www.wwpc.eu.com). As the world’s largest dedicated Project Freight Forwarding and Logistics Management Organization, they operate under a strict Code of Conduct. Only the most dedicated, experienced and viable experts in project forwarding, with a proven track record, are admitted as members. They only choose the most experienced and viable experts in project forwarding and with a proven track record, to be admitted as a member. Concargo will assist them in project management and logistics planning of large, extra heavy, dangerous and difficult cargo.
“We are extremely proud to have qualified and been accredited by two of the most prestigious Abnormal Out-of-Gauge Heavy Lift organizations on the globe as their strategic partners and members of their network for South and Sub-Saharan Africa. With 21 years of Logistical services to Forwarding Agents’ and General business in Southern Africa, we can provide the Supply Chain Solutions and Logistics Planning our clients have come to rely on,” says David Kruyer, Concargo CEO.
IF YOU CAN'T MEASURE IT, YOU CAN'T MANAGE IT
Increasingly, companies are waking up to the challenges of delivering sustainable objectives, especially in light of our current energy crisis. From emissions trading to proving cost reductions - businesses need reliable and accurate information.
According to Douglas Weinrich, Regional Executive at Johnson Controls Global WorkPlace Solutions South Africa: "The first step in any corporate energy management programme is to determine total energy usage and spend. This is not only necessary to set realistic goals. It is also critical to document the success of the programme both internally and for external stakeholders."
But identifying the amount of energy being used is not as easy as it sounds. Historically, energy meters have been manually read at variable times. This method of data collection is time consuming, costly and susceptible to human error. Using a central database of utility consumption can help.
"If businesses want in-depth, accurate energy usage information, smart metering is the way forward. By recording energy consumption on a regular basis, every half hour for instance, new metering technologies allow the user to establish a true pattern of energy usage and help identify any unusual trends," says Weinrich.
With this information, businesses can identify quick wins to reduce electricity, gas and water consumption, such as stopping water leaks. Metering also highlights malfunctioning equipment, areas of wastage, unusual peak loads and unauthorised usage. In trials with major multi-site businesses one smart metering solution detected errors of over 60% on some gas bills and nearly 50% on some electricity demands. There is, of course, a cost associated with this type of technology, but for as little as a R294,000 investment, metering can produce annual savings of hundreds of thousands of rands running into millions of rands.
After clarifying energy consumption, the next step in an energy management programme is bill validation. Often, when companies are asked for the last year's energy bills, the request is often met by a stunned silence. But it's a worthwhile process and the facts speak for themselves.
It is expected that energy prices are going to increase significantly in South Africa. It is therefore prudent for businesses to look towards responsible energy management.
Global Workplace Solutions South Africa
Regional Executive: South Africa
Tel: 011- 4381600
The Golden Crown of Johannesburg
By Gerhard von Ketelhodt
Central Rand Gold (CRG), South Africa’s newest gold mining company is planning to reopen old worked out areas on the Central Witwatersrand where 120 years ago the largest and richest deposit of gold was discovered.
It is estimated that there are still millions of ounces of gold to be gained from the very site where gold was mined following the discovery of the Witwatersrand Goldfield.
How can one be sure that there are so much gold to be won and how is it going to be possible to determine precisely where the best places are to start operations?
One man, the author of The Golden Crown of Johannesburg, Gerhard von Ketelhodt, knows the answer. Von Ketelhodt, who was the last mine overseer at Crown Mines to work in the area about to be opened, knows where the millions of ounces of gold to be mined are located.
The ‘Golden Crown’ was Crown Mines, in its heyday the world’s greatest and richest mine. That old mine was the lifeblood of Johannesburg, a city which grew from a mining camp into a great metropolis in just a few decades. In his book, a new release, the author relates how Crown Mines was established, its heyday, its decline and its hard fought battle for survival.
How Gerhard Freiherr von Ketelhodt, a man of noble rank, a Baron from Germany, came to join Crown Mines in 1956 is part of an incredibly fascinating story. Von Ketelhodt emigrated to South Africa from Germany to manage a farm in the Eastern Cape, but having qualified as a coalminer in the Ruhr district in Germany subsequently joined Crown Mines as a learner miner in 1956. He describes his life and experiences on the mine and how he had to overcome not only the difficulties and hardships inherent in the job but also the problems of communication when he arrived without a knowledge of English, Afrikaans or Fanagalo.
In relating his experiences during his twenty years of active underground mining deep under Johannesburg’s bustling skyline, where he personally experienced the pick-and-shovel heartbeat that kept the industry going he pays tribute to the unsung heroes of mining, the men who went deep down in mineshafts at some considerable risk to break hard gold-bearing rock and to deliver it to gold processing plants.
The Golden Crown of Johannesburg’ is an unusual book in many respects. It is factual, informative and entertaining.
Written in the matter-of-fact style of a practical mining man, the book should appeal to anyone who has ever had anything to do with mining and to readers who are fascinated by gold and stories about the real heroes of mining, the mineworkers who risk their lives by going deep down the earth
The Golden Crown of Johannesburg contains more than 100 historical mining photographs; more than twenty true stories about acts of bravery carried out by mine rescue teams; narrow escapes and disasters; humorous incidents, and even witchcraft.
In his description of his family life in a mining community he also mentions how, because of living in close proximity of Crown Mines ‘native’ labour quarters, the family from Germany was introduced to the African way of life.
As a member of the stringently selected Chamber of Mines Proto Team, he took part in numerous emergency and rescue actions involving trapped and injured miners on the Reef mines in and around Johannesburg and Free State mines.
There is a section devoted to frequently asked questions about gold, gold mining and gold products.
Ros Adams, Editor, Mining Africa Yearbook
“THE GOLDEN CROWN OF JOHANNESBURG”
A Book Review
The resumption of mining operations on the Central Rand by Central Rand Gold (Modern Mining, January 2008) will be celebrated through the launch of a new book about South Africa’s – and the world’s – most famous gold mine, Crown Mines. However, this is no conventional history of a mine; this is the story of his life as a miner on Crown Mines of a German nobleman Baron Gerhard von Ketelhodt. Von Ketelhodt did not choose the easy road in life; he chose the road least travelled, that of a miner in the most hostile working environment on earth – a deep South African gold mine.
Yet far from complaining about a difficult life under arduous conditions, Von Ketelhodt lived his new life in South Africa as an adventure filled with excitement and discovery, camaraderie and triumph in adversity. He recounts his story with freshness and verve and it is a tribute to all those who have worked on the South African gold mines and contributed so much to the building of modern South Africa and our great city, Johannesburg.
Despite these difficulties, von Ketelhodt thrived in his new environment. He married his wife, Erika, also a German immigrant in the Friedenskirche in Hillbrow and they had four sons. Not content with the daily challenges of his job, he sought further service to the industry through joining the Proto Team at Crown Mines, a fire and rescue team which was available at all times for rescue operations on any gold mine in South Africa.
The stories and anecdotes in the book will resonate with all those who have worked underground on the South African gold mines and will fascinate those who haven’t. The author also sketches the background to the Crown Mine’s operations within the context of the industry and the life of the times and he describes with nostalgia and sadness how the relics of the past glories of the mining era such as shaft headgears have been replaced by the mundane features of modernity such as motorways and factories.
This is a valuable contribution to Africana and our cultural heritage. However, there remains much scope for further research and it is hoped that the work will be expanded in a subsequent edition to add a more formal and detailed history of the mine to Von Ketelhodt’s personal experiences.
NON-MINING TECHNOLOGY TO TACKLE MINE SAFETY
The mining industry is unlikely to achieve its safety targets unless it looks beyond mining for solutions.
That's the view of Inus Dreckmeyr, MD of Proudly South African electronic research and development house, Netshield SA, who believes that advances in the Information and Communications Technology (ICT) sector - particularly in the wireless arena - could provide some answers.
Dreckmeyr notes that the Mine Health and Safety Council's (MHSC's) latest annual report which was tabled in parliament recently lists machinery and transport accidents as responsible for the second highest number of fatal accidents on mines, after rock-related incidents. Factors that influence the contribute to the high number of accidents include an increase in the number of seismic events and the amount of moving machinery being used on the mines, as well as human behaviour.
"Much of the focus on mine safety, most research and a high proportion of the safety budget, is directed at reducing rock-related accidents. But mines also need to direct more attention at reducing locomotive and transport accidents. Using radar, wireless and smartcard technology innovatively, could go a long way towards reducing - if not eliminating - many of these accidents," he says.
According to Dreckmeyr, mines use warning signs and signals to indicate the existence of collision danger zones. This, he feels, is not enough as there may be a problem with visibility.
"In addition, when someone sees something often enough - such as a warning sign - its impact wanes. And if the driver is not concentrating, he may not see it at all," he says.
A solution, he suggests, would be to install a system that provides an audible and visual signal of impending danger - to be activated only when such danger exists. In other words, instead of drivers having to stop at a particular spot every time they pass it in order to check for oncoming traffic, a system could be implemented that will sound and flash a warning only if there is traffic approaching.
The same technology could be employed to force drivers to slow down when travelling too fast or approaching danger zones, or to prevent them from inadvertently getting too close to other objects or people.
"Netshield is currently developing such a system which we expect to launch later this year," Dreckmeyr concludes.
For additional information contact:
WINNERS OF NEDBANK'S CAPITAL GREEN MINING AWARDS
The winners of the second annual Nedbank Capital Green Mining Awards, which seek to acknowledge and celebrate the contribution that responsible mining and mineral beneficiation makes to the economic development of Southern Africa, were announced last night at a ceremony at Nedbank's head office in Sandton.
The winners are: Amandelbult Platinum Mine for its Amandelbult Environmental Management System in the Environmental category; Ekapa Mining for its Flamingo breeding island at Kamfers Dam in the Limited Resources category; Anglo Coal for its Basa Njengo Magogo Vosman alternative fire-lighting project in the Socio-economic category; and Anglo Coal and BHP Billiton Energy Coal South Africa (BECSA) for the Emalahleni Water Reclamation project in the Sustainability category.
Mark Tyler, head of Mining & Resources at Nedbank Capital says: "We were encouraged by the standard of the winning projects for this year's awards - Ekapa Mining's Kamfers Dam and Anglo Coal's Emalahleni Water Reclamation projects in particular, are world class. Entries were welcomed from the entire African continent this year, but for now, the winners' trophies remain on South African soil.
"The response to this year's awards indicates that awareness around sustainability has increased, and that more and more mining companies are striving towards a more sustainable future for their mines and those communities affected by them. We encourage and look forward to entries from the junior, mid-tier and major mining companies for the awards next year," said Tyler.
The Environmental category winner, Amandelbult Platinum Mine's Environmental Management System, was recognised for the positive impact it has had on both the mine and the community. Since 2000, Amandelbult Mine has implemented a sustainable Environmental Management System (EMS) to continually improve on its environmental risk identification and impact management. This initiative reaches beyond compliance; the EMS has been integrated into the entire operation and has been extended to benefit communities beyond the mine boundaries. This has resulted in more sustainable practices both at the mine and within the community. Other positive elements of the EMS include effective education of employees, contractors and local school learners; environmental and species protection; partnerships and the inclusion of community input and involvement; and job creation.
Ekapa Mining received the Socio-Economic Award for its exceptional Flamingo Breeding Island at Kamfers Dam Project. This majority black-owned junior mining company, based in the Northern Cape, sponsored, designed and constructed an artificial flamingo breeding island, the first such structure in Africa, in order to contribute to the conservation of the continent's threatened Lesser and Greater Flamingos. The project is a unique, world-class contribution to saving a threatened species. Other commendable aspects of the project include the strong partnership approach which involved local government and local community organisations; an innovative approach to the design of the artificial breeding sites; positive socio-economic impacts, such as tourism and strong biodiversity benefits, principally species protection; and the fact that the project has research, education and tourism potential which Ekapa Mining could consider enhancing further.
Anglo Coal's Basa Njengo Magogo Vosman Alternative Fire-lighting Project, winner of the Socio-economic category, was recognized as an exemplary example of a simple, low technology solution to a major health and social issue. High levels of air pollution associated with household coal burning are known to create severe health and environmental problems, especially during the winter months when coal is not only used for cooking, but as an essential heating source. Although it does not sell coal to households, Anglo Coal elected to promote a low-cost coal burning intervention that teaches families to make fires in a much healthier, more cost effective and environmentally friendly way. Anglo Coal adopted an innovative approach to awareness raising by using a community member as the role model. This together with appropriate, effective communication tools and good community engagement has ensured a high adoption rate from people exposed to the method. Household cost savings, reduced air pollution and reduced health impacts have also resulted from the initiative.
Anglo Coal and BHP Billiton Energy Coal South Africa (BECSA), the winners of the Sustainability Category, were lauded for their Emalahleni Water Reclamation Project, labeled a 'world-class project and an exemplary model for development in the Nedbank Capital Green Mining Awards Sustainability Category' by the adjudicators. The companies, in a pioneering private-public partnership also involving the Emalahleni Local Municipality, initiated a project to remove water from the underground workings of four mines and to desalinate it to potable quality for supply to the water-stressed municipality's final reservoirs. The project addresses the mining and environmental liabilities associated with polluted underground water, and benefits the local community by supplementing the currently low domestic water supply. Once operating at full capacity, the plant will meet 20% of the local authority's daily water requirements. With substantial growth taking place in the Witbank region, this project assists in meeting growing municipal, commercial and industrial water needs
Issued by Nedbank Media Relations
Thabazimbi Projects R2.5 Million Savings Using Locally Developed Dust Suppressant
Thabazimbi mine anticipates a saving in excess of R50 000 per month as a locally developed dust suppressant product is being utilised on the pit's road surfaces in their Kwaggashoek East open pit section.
The product, Roads Environmental Dust Suppressant (REDS) developed locally by Samchem, is being tested over a six month period.
The tests, which began a month ago, are already showing impressive results at the Kwaggashoek East open pit, one of four pits.
On water usage alone there are savings of up to ninety six percent, saving over 5,5-million litres of water per month.
"Using water as a dust suppressant needed 128 trips per month in a bowser truck, with each trip having a distance of up to six kilometres and 45 000 litres of water used on each trip. We now only do one trip a week, over weekends, which does not disrupt the normal days work," says mine pit superintendent Grant Crawley.
"The monthly savings of R50 000 exclude water usage and only covers diesel savings, vehicle maintenance and tyre wear and tear. If we included water savings the figure would be significantly higher."
"There are benefits also to the environment, to employee health and overall safety. The product bio degrades in thirty days."
"In terms of safety, high levels of dust have been known to cause vehicle collisions, and excessive dust affects employee health," says Crawley.
"Water is currently being applied in the other pits. It needs to be applied up to six times a day. REDS is also more cost effective than other products which are not biodegradable, are more expensive, use more water, require a specially developed douser vehicle and can cause damage to vehicle paintwork and tyres."
"Overall, using REDS at all four pits could see savings of over 2.5-million per annum," says Crawley.
Contact: Belinde Mans
Administration & Marketing Manager
Samchem Drilling Fluids & Chemicals
Tel: + 27 11 908-5595
Fax: (011) 908-5887
Andrew Evans, Industrial Lubricants Marketing Manager at Shell Lubricants South Africa discussed how the changing needs of the coal mining industry are putting the spotlight on effective lubricant management to help maintain productivity.
Lubrication has long been the hidden hero of the coal mining industry; essential to the smooth running of the mine, yet rarely seen as key to productivity.
Over the past three years however, with the soaring price of coal and the resulting pressure on operators to increase output, effective lubrication has become more important than ever. And the challenge to lubricant suppliers is to address the sector’s changing needs with on-the-ground technical support, ancillary services and targeted product development.
“The rising price of coal is great news for the coal mining industry and has led to lots of investment,” explains Evans “but essentially it means that operators are using the same equipment to produce coal at a much more intensive rate.
“Equipment utilisation, reliability and availability are key factors in gaining optimum operating hours between service intervals, which put extra pressure on the lubricant to perform. It is also prompting operators to try to run machinery for longer without a service break.”
Shell Lubricants SA have discovered that many coal mine operators are now attempting to increase certain component life from 16,000 hours to 20,000 hours. “A 25% increase in the working life of components is an extremely ambitious target and, where it is achievable, it can have significant cost benefits,” Evans continues. “However, it also carries considerable risks, including component failure and oil break down. Either of these scenarios can result in unscheduled and expensive production stoppages/losses that may outweigh the financial gain of extending component life, increasing rebuild intervals and driving greater throughput.”
In addition to achieving production efficiencies by driving component life to its limits, operators are also trying to maximise production rates by extending service intervals and, therefore, extending oil drain intervals. “On the face of it, extending oil drain intervals can help achieve significant production efficiencies as it reduces stoppages. However, it also increases the risk factors,” comments Evans. “The lubricant is required to work harder and longer to protect components over a longer time period, so its effectiveness will decline, just as the need for effective lubrication of components increases. Unless the right lubricant is used and carefully monitored, the end result can be unscheduled stoppages – just the opposite of what the operator is trying to achieve.
“As one of the essential elements of equipment efficiency, effective lubrication management must be factored in to production efficiency programmes, and more and more mine operators are calling on the expertise of their lubricant supplier to help them achieve their output goals.”
The first step in pushing equipment longer and harder to increase productivity is to ensure the lubricants used have the high performance capabilities to cope with more intense production levels.
“Even with a high quality lubricant, the risks of extending oil drain and service intervals and increasing component life are high if the lubricant’s effectiveness is not carefully and regularly monitored. Oil Condition Monitoring (OCM), not only allows the operator to identify any shortcomings in the lubricant’s efficiency, it can pinpoint any abnormal trending or wear rates, giving the operator an indication of whether they might be pushing their equipment too hard.”
OCM involves the analysis of oil samples taken at specific points in the equipment at regular intervals to monitor changes in the lubricant that could indicate current or potential problems with the equipment. Evans explains: "When studied by Shell Lubricants experts, the condition of the oil, the pace of its deterioration and the presence of contaminants can all provide indicators of equipment performance. This analysis can be used to provide a simple traffic light status of the equipment's condition and recommendations of what preventative action needs to be taken and when."
Implementing an OCM regime supports extended oil drain and service intervals by reducing the risk of resulting maintenance problems going unnoticed. Evans continues: “While avoiding scheduled downtime can help increase production levels, unscheduled downtime can have an adverse affect on overall output, particularly where mines are remote and may have to wait for a service engineer or new components to arrive on site. OCM allows operators to manage this risk by picking up potential problems early enough that maintenance can be scheduled in before unplanned stoppages and reactive maintenance is required.”
The effectiveness of OCM relies on the sampling methodology and the accuracy of the resulting data. Shell’s mining specialists work with customers to ensure that they get this right from the very beginning. This process usually begins with a Shell Lubricants expert recommending the right product for the equipment and operational requirements. With the correct products in place, the next step is to ensure operators are trained to carry out the lubrication programme correctly. In addition, operators are extensively trained in sample-taking methods and Shell Lubricants recommend the appropriate set of tests for each application to establish a suitable OCM programme.
Results of OCM analyses provide to the operator with risk alert; allowing them to know whether the lubricant and equipment are working effectively, alerting them to a potential problem highlighting an existing issue that must be addressed immediately.
Evans continues: “OCM programmes are tailored to meet the customer’s specific needs. We discuss the operator’s productivity objectives with them and design a lubrication management system that will help support their goals so that any risks they take in driving their equipment are calculated and carefully monitored.”
For as long as operators can benefit from the high demand for coal by increasing production levels, the question of how to drive productivity without damaging profitability through unnecessary reactive maintenance will continue to challenge the industry.
“There is no single answer to how intensively a mine can produce before it runs into problems, as every site is different,” adds Evans “but for operators that understand the vital role that lubricants can play in both enhancing equipment efficiency and revealing potential faults, lubrication can play an important role in managing the risks of extending component life, and increasing service and oil drain intervals.”
Issued For: Shell SA
Contact: Andrew Evans, Industrial Lubricants Marketing Specialist: 011 996 7264
Email: email@example.com Website: www.shell.com
AO Safety Shed a Little Light on the Subject
Leading safety company, MSA Africa, is the first in South Africa to launch the all new AO Safety Light Vision LED safety spectacle, the first industrial eyewear designed with integral hands-free lighting.
This innovative safety spectacle provides the benefit of safety and lighting, Light Vision eyewear can be used in all industries where extra light is required, including machinery or automotive repair, medical, emergency services and lab work, wire junction boxes, night rescue and police search.
The glasses are designed to offer all the protection of standard safety eye-wear. They provide wide coverage, and their wrap-around shape protects against flying particles. The lens is made from impact resistant polycarbonate with anti-fog coating and the soft rubber temples and nose pads offer comfort for extended wear.
The hands-free lights, conveniently positioned on the temples of the glasses, comprise an ultra-bright LED system. They have a swivel mechanism to facilitate directional lighting, and a long battery life of up to 50 hours. For extra convenience the batteries are also easily replaceable.
For further information, please contact MSA Africa on (011) 610 2600 or visit www.aosafety.com.
Ingenious Air Suspension Helps Multi Axle Specialist Break the Sub-4.5 ton Load Barrier
A Brisbane-based vehicle conversion specialist is employing an ingenious air suspension to overcome load capacity problems faced by both fleet operators of big trucks and individual operators of smaller work and recreational vehicles including 4wds.
Multi Axle Conversions of Brendale has teamed with air spring and air suspension innovators Airbag Man to produce suspensions that enable sub-4.5 tonne vehicles to handle up to double their normal payload - yet be outstandingly tractable and safe on the roughest mine, construction and farm sites.
The ruggedly re-engineered 4wd and specialist vehicles fitted with twin rear axles can be driven by people with a standard licence that permits them to operate vehicles up to 4.5 tons.
For further information about this media release, please contact Airbag Man: firstname.lastname@example.org or
Vein' Reading Could Save SA Mines Millions
Failsafe new technology allowing people to be identified by their veins can save South African mines millions of rands each year. Vein scanners are faster and more effective than fingerprinting.
The scanner "reads" a person's veins through a photo and heat process. Just as everyone's fingerprints are unique, their heat emission and vein patterns are similarly unique.
"The greatest advantage of this sophisticated and affordable system is the speed and accuracy with which people can be identified," says DexGroup Informatix's Jans Wessels. It is possible to identify a person in less than half a second, and the system is 99% accurate.
There are also the time saving advantages - the number of people underground can quickly be determined in cases of mine accidents or earth tremors.
Vein scanners can also be used to ensure that miners have undergone medical examinations. The new technology can deny a miner access in the canteen or a shaft if he has not gone for a medical examination.
Biometric or fingerprint technology is also difficult to apply because of "damaged" fingerprints or grimy fingers.
The new technology can play an important role in cost saving in mining, fraud committed by wages paid to ghost workers, unauthorised use of mine canteens and the management of equipment and clothing handed out free by the mine.
Although most mines in South Africa exercise relatively strict first phase access control, they are often vulnerable when the first point of control has been passed. Industrial espionage is also possible owing to unauthorised entry. Vein scanners prevent "buddy clocking" and can be applied in conjunction with conventional clock systems. The technology is also highly effective in conjunction with card access systems.
The system is currently being tested at some of the largest mines in the country.
Optical Sorting of Tanzanite Concentrate
The advancements made in the development of electronic sorting technology have made it very versatile in its applications. In 2003/4 one such application was commissioned at the TanzaniteOne mine in Merilane, Tanzania.
The uniqueness of this application is underlined by the fact, that the world’s only known source of Tanzanite is situated in the Simanjiro district of Tanzania, 70km south-east of Arusha and 16km south of Kilimanjaro International Airport.
Tanzanite is located in a relatively complex geological environment and is found in ‘chocolatetable’ boudin structure, typically located in the hinges of isoclinal folds (folds dipping in the same direction) present in the ore body. The Tanzanian government demarcated the tanzanite mining area into 4 Blocks: A, B, C and D, measuring approximately 5km by 2 km in total. The TanzaniteOne Group owns the mining licence for the largest area, Block C.
Geological tests have revealed that the supply of gemstones will be exhausted within approximately 15 – 20 years.
Tanzanite is a gemstone variety of the mineral zoisite. Zoisite’s occurrence in the presence of vanadium (and hence the formation of tanzanite) is exceptionally rare.
Tanzanite Grades A, B/C and D
2. Processing of Tanzanite Concentrate
Tanzanite is mined underground, via production drives that extend from decline shafts, running on dip of the ore body. The ore is hoisted to surface from where it is transported by truck to the plant.
A screening and crushing process reduces the material to a -30mm size fraction, before it enters into a dense media separation (DMS) process to recover the denser tanzanite (SG 3,35). The DMS floats are discarded, whereas the DMS sinks is collected in a skip which tips the concentrate onto a slide entering the recovery room.
Picture 4: TanzaniteOne processing plant
Picture 5 shows the block plan of the sorting plant. The DMS concentrate is screened on a tripledeck Sweco washing screen, so that the feed for the sorting machines is in a size range ratio of not more than 3:1. The washing of the feed material is very important as it removes all the dirt and dust off the particles, so that the true surface colours of the stones are exposed to the camera system of the sorters. These size fractions are then fed to two MikroSort ConcSort BSX-063 machines via two 600 mm wide pan feeders. The first ConcSort BSX-063 processes 240 kg/h of material with a size range of -30 mm +12 mm. The second unit incorporates two tracks, one to sort 210 kg/h of material with a size range of -12 mm +5 mm, and the other to sort 150 kg/h of -5 mm +2 mm.
The fine material (-5mm +2mm) is dried by means of hot air blown onto the feeder. This prevents lumping of the feed material which would have a marked impact on the sorting efficiency in this size range. The coarse +5mm material is fed to the sorting in a drip dry condition. The moisture on the stones in this case is important, as it enhances the natural colours of the ore.
3. Flow sheet and Equipment
The sorting plant comprises of the following main equipment:
• 2 off MikroSort ConcSort BSX-063 machines
• 2 off electromagnetic pan feeders for feeding the MikroSort machines
• Dust extraction system
• Compressor and air receiver
• 4 off conveyor belts for the supply of the feed material to the MikroSort machines
• 1 off conveyor belt for the removal of the sorted material
• 1 off air knife drier for the drying of the -5 +2 mm fraction
The working range of the compressor station is set between 4.5 and 7.4 bar. The two sorters are set at different pressure level: Sorter 1 (-30mm +12mm) at 6,5 bar; Sorter 2 (-12mm+2mm) at 5 bar.
The belt speed of both sorters are set at 2,75 m/s. The total power requirement for the sorting plant is approximately 60kW.
4. Sorting Process
The sorters are fitted with a dual illumination system to utilize the reflected light properties as well as the transparency properties of the particles.
The example of the sorting algorithm is illustrated in picture 12. It shows the settings to separate the above rock types by using a combination of colour and brightness of both the reflected and transparent light properties of the material.
Two MikroSort machines have been commissioned in the sort-house at TanzaniteOne Mining Ltd, producer of the world’s rarest coloured gemstone, tanzanite. The mine is located in the foothills of Mount Kilimanjaro in Tanzania. The opto-electronic sorting technology is substantially improving recovery efficiencies, throughput and security within the sort-house at the mine.
The sorting plant is used for separating tanzanite fractions from waste by colour and transparency, two of the many optical properties that can be used to programme the MikroSort machines.
Tanzanite bearing material from the heavy media separation plant is washed and screened on a tumbler screen before being fed to two MikroSort ConcSort BSX-063 machines via two 600 mm wide pan feeders. The first ConcSort BSX-063 processes 240 kg/h of material with a size range of -30 mm +12 mm. The second unit incorporates two tracks, one to sort 210 kg/h of material with a size range of -12 mm +5 mm, and the other to sort 150 kg/h of -5 mm +2 mm. TanzaniteOne Mining sort-house’s MikroSort system is meeting the production requirement for which it was developed. 80% purity with a 98% recovery rate is being achieved. The product lost is low grade tanzanite that has no colour or crystal structure.
Lütke von Ketelhodt, Johan Jacobs
Firma/Hochschule – IMS Engineering (Pty) Ltd – MikroSort Division
Straße – 6 Eastern Services Road
PLZ, Ort – Eastgate Ext. 3, Sandton 2199, South Africa
 HARTWIG, I. (2002): Test Report, Separation of Tanzanite (High and Low Grade) from Concentrate Tailings, Wedel
 WIEHL, K. (2004): MikroSort Machines for AFGEM, Product Function Specification.
 BROOK BROWDE COMMUNICATIONS, (2005): MikroSort – Unique Recovery Process for Rarest Gem.
 BANCROFT P. (1984): Gem&Crystal Treasures, Western Enterprises/Mineralogical Record, Fallbrook, CA, 488 pp.
 JACOBS J. (2005): Machine Upgrade and Service Report 18-25August 2005