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| 4E (Pt) |
Four elements. The grade at Anglo Platinum mines is always measured as the combined content of the four most valuable precious metals - platinum, palladium, rhodium and gold
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| A |
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| AE |
Autorisation d'Exploration |
| AEM |
Airborne electromagnetic survey |
| Ag |
The chemical symbol for silver |
| Alluvial |
Deposited by the action of running water in a stream |
| Alteration |
Changes in the composition of a rock, generally chemical or mineralogical, brought about by weathering or hydrothermal activity |
| Arisings (Pt) |
The valuable product after a stage in processing |
| Arsenopyrite |
A sulphide mineral of arsenic and iron (Fe AsS) |
| Assay |
The chemical test of rock samples to determine their mineral content |
| Assay |
To analyze the proportions of metals in an ore |
| Au |
Chemical symbol for gold |
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| B |
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| Backfill |
Waste material used to fill the void created by mining an ore body with the purpose of providing both regional and localised support |
| Below Collar |
A distance below the surface elevation of a shaft |
| Bench (Pt) |
The equivalent of a level in an underground mine most noticeable as the step-like features in an open-pit wall. The open-pit bench height is calculated to match the rock strength, pit economics and capabilities of the open-pit machinery. Typical bench heights in open-pit mines range from 10 to 20 metres. |
| Best Cut (Pt) |
The optimum stoping width for mining of the reef at prevailing metal prices and costs. |
| BIC |
Bushveld Igneous Complex |
| Birimian |
Geological Time Era, about 2.1 billion years ago in which a suite of rocks charateristic to West Africa formed |
| Boudinage |
A structure common in strongly deformed sedimentary and metamorphic rock, in which an original continuous competent layer or bed between less competent layers has been stretched, thinned and broken at regular intervals into bodies resembling boudius or sausages |
| Breccia/Brecciation |
Rock type, formed from recrystallised fragments of other rocks |
| Built-up Head Grade (Pt) |
The total 4E grams produced from the concentrating process from concentrate, metallics (where applicable) and tailings divided by the total tons milled. |
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| C |
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| Capex |
Capital expenditure |
| Carat |
From the Arabic quirrat seed, unit for measuring the mass of precious stones; it is equal to 0,2g/0,00705 oz, and is part of the troy system of weights. It is also unit of purity in gold (US karat). Pure gold is 24-carat (the purest used in jewelry, is 22 parts gold and 2 parts alloy) to give greater strength. |
| Carbon-in-leach |
A recovery process in which a slurry of gold ore, carbon granules and cyanide are mixed together. The cyanide dissolves the gold which is absorbed on the carbon. The carbon is subsequently separated from the slurry for further gold removal. |
| Carbon-In-Leach (CIL) |
Similar to the CIP plant except the gold is leached and absorbed onto carbon granules in the same circuit. The carbon granules are separated and eluted in the same way as for CIP. |
| Carbon-in-pulp |
Similar to carbon-in-leach process, but initially the slurry is subjected to cyanide leaching in separate tanks followed by carbon-in-pulp. Carbon-in-leach is a simultaneous process. |
| Carbon-In-Pulp (CIP) |
Gold is leached conventionally from a slurry of gold ore with cyanide in agitated tanks. The leached slurry passed into the CIP circuit where carbon granules are mixed with the slurry and gold is absorbed onto the carbon. The granules are separated from the slurry and treated in an elution circuit to remove to gold |
| Cash Costs |
Cash costs include site costs for all mining (excluding deferred development costs), processing and administration, but are exclusive of royalties, production taxes, amortisation and rehabilitation, as well as corporate administration, capital and exploration costs. |
| Channel Width |
The total thickness of all reef bands including internal waste. |
| Co |
Chemical symbol for cobalt |
| Concentrating (Pt) |
This is the process of separating milled ore into a waste stream (tailings) and a valuable mineral stream (concentrate) by the flotation operation. The valuable minerals in the concentrate contain almost all the base metal and precious metal minerals; these minerals are treated further by the smelting and refining process to obtain the pure metals (Cu, Ni and Platinum Group Metals). |
| Craton |
A part of the earth's crust that has attained stability and has been little deformed for a long time |
| Cu |
Chemical symbol for copper |
| Cut-off grade |
The lowest grade material that can be included in a potentially economic intersection without dropping the overall grade below a specified level, referred to as the minimum mining grade. Lowest grade of mineralised material that qualifies as ore. |
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| D |
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| Decline (Pt) |
A generic term used to describe a shaft at an inclination below the horizontal and usually at the same angle as the dip of the reef |
| Development |
The process of exposing an ore body through tunneling |
| Development (Pt) |
Any tunnelling operation which has for its object either exploration or exploitation. |
| Development waste |
All development in country rock. |
| Development-Reef |
All development on the reef horizon. |
| Diamond drilling |
A rock drilling method using a rotary diamond bit which is attached to long hollow rods. The drill cuts a cylindrical core of solid rock, recovered for geological and metallurgical examination, and assay purposes |
| Dike |
A tabular igneous intrusion that cuts across the planar structures of the surrounding rock |
| Dilution |
Mixing of ore grade material with non-ore grade/waste material in the mining process |
| Dip |
The angle that a structural surface, a bedding or fault plane, makes with the horizontal, measured perpendicular to the strike of the structure |
| Direct reduced iron (DRI) |
A process by which iron ore (65-70% Fe203) is reduced, using reformed gas, and produces metallic iron ore pellets (90-93%Fe); these pellets can be used in replacement of scrap steel in electric-arc furnaces |
| Drill-core |
The sample of rock obtained by diamond drilling |
| Dwt |
Pennyweight |
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| E |
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| Exclusive Exploration Permit |
| Exploitation Permit |
| Chemical process of recovering gold after elution process |
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| F |
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| Face Advance (Pt) |
The average distance the stope face advances per month. A measure of resource utilisation. |
| Fault |
A fracture in rock along which there has been an observable amount of displacement |
| Feasibility study |
A definitive engineering study addressing the economic viability of bringing a deposit to the production stage; taking into consideration all associated costs, revenues and risks. The study is used to support the search for project financing. |
| Flotation (Pt) |
In the flotation process milled ore mixed with water or pulp is passed through a series of agitated tanks. Various chemicals are added to the pulp in sequence to render the valuable minerals hydrophobic (water repellant) and the non-valuable minerals hydrophilic (water loving). Air is dispersed throughout the agitated tanks and rises to the surface. The hydrophobic particles attach to the rising air bubbles and are removed from the main volume of pulp as a soapy froth. In this manner various combinations of flotation cells in series are utilised to produce a concentrated stream of valuable mineral particles called the 'concentrate' and a waste pulp stream called 'tailings'. |
| Footwall |
The underlying side of an orebody |
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| G |
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| G/T |
Grammes per metric tonne gold |
| Geophysical surveys |
A survey method used primarily in the mining industry as an exploration tool, applying the methods of physics and engineering to the earth’s surface. Exploration by observation of seismic of electrical phenomena and the earth’s gravitational or magnetic fields, using specialized instrumentation |
| GIS |
A geographical information system is a computerised relational database for spatial information |
| Grade |
The amount of valuable element in each ton of ore, expressed as troy ounces per ton for precious metals and as a percentage for other metals Cut-off grade is the minimum metal grade at which an ore body can be economically mined Millhead grade is the metal content of mined ore going into a mill for processing Recovered grade is actual metal content of ore determined after processing Reserve grade is estimated metal content of an ore body, based on reserve calculations |
| Grade also "yield" |
Gold recovered per unit of rock milled or treated. Normally measured as grams of gold per ton of rock |
| Grain |
The smallest unit of mass in the three English systems (avoirdupois, troy and apothecaries’ weights) used in the UK and USA, equal to 0,0648g. It was reputedly the weight of a grain of wheat. One pound avoirdupois equals 7 000 grains; one pound troy apothecaries weight equals 5 760 grains |
| Gram |
Metric unit of mass; one thousandth of a kilogram |
| Granite |
A medium to coarse grained igneous intrusive rock in which quartz constitutes 10 to 50 percent of the felsic components |
| Granitoid |
Geological rock type |
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| H |
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| Hanging Wall |
The overlying side of an orebody |
| Hard-rock gold mining |
The mining of gold deposits in bedrock, i.e. deposits other than alluvial, colluvial or eluvial deposits |
| Head Grade |
The gold contained in material passing through the mill in grams per tonne or troy ounces per short ton milled |
| Heap leaching |
A process whereby metals are extracted by heaping broken ore on an impermeable pad, and repeatedly spraying with solutions which percolate through the heap, dissolving a high percentage of the metal content. The resulting mineral solution is then collected for metal recovery generally by electro-winning |
| Heap/dump leaching |
A process whereby gold is extracted by "heaping" broken ore on sloping impermeable pads and repeatedly spraying the heaps with a weak cyanide solution which dissolves the gold content. The gold-laden solution is collected for gold recovery |
| Heavy minerals |
Minerals with high specific gravity such as ilmenite, zircon, garnets, magnetite and rutile |
| Hedging |
Generally refers to any precaution against risk. In the context of gold mines refer specifically to measures to reduce the risk of gold price fluctuations – particularly a fall in the gold price. Hedging has almost become standard practice to "insure" funding over the duration of large capital expenditure programs. Hedging the gold price is done by forward contracts and options and has developed into quite an art form. |
| Horizon |
A plane of stratification assumed to have been once horizontal and continuous |
| Hydrothermal |
Process of injection of heated or hot acqucous-rich solutions into existing rocks |
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| I |
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| Igneous |
Formed by the solidification of hot mobile material termed magma |
| Immediately available ore reserves (Pt) |
Ground available for mining without any further development |
| Indicated Mineral Resource |
is that part of a Mineral Resource for which tonnage, densities, shape, physical characteristics, grade and mineral content can be estimated with a reasonable level of confidence. It is based on exploration, sampling and testing information gathered through appropriate techniques from locations such as outcrops, trenches, pits, workings and drill holes. The locations are too widely or inappropriately spaced to confirm geological and/or grade continuity but are spaced closely enough for continuity to be assumed |
| Inferred Mineral Resource |
is that part of a Mineral Resource for which tonnage, grade and mineral content can be estimated with a low level of confidence. It is inferred from geological evidence and assumed but not verified geological and/or grade continuity. It is based on information gathered through appropriate techniques from locations such as outcrops, tenches, pits, workings and drill holes that may be limited or of uncertain quality and reliability |
| In-Situ |
The original, natural state of the orebody before mining or processing of the ore takes place |
| Internal Waste |
Any waste within the reef channel |
| Intrusion |
The process of emplacement of magma (naturally occurring molten rock material generated within the earth) in pre-existing rock |
| IP Survey |
Induced polarisation survey |
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| K |
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| Kimberlite fissures |
Kimberlite fissures or dykes are intrusive bodies occurring along structural weaknesses in rocks. Generally economic diamond-bearing fissures in South Africa average 600mm to 800mm in width and may well be more than 5 km in strike length |
| Kriging |
An interpolation method that minimises the estimation error in the determination of mineral resources< | | | | |