EDUCATION - INDUSTRY TERMS - BASIC MATERIALS - GOLD

Assay
The chemical test of rock samples to determine the metal content.

Autoclave system
Oxidation process in which high temperatures and pressures are applied to convert refractory sulphide mineralization into amenable oxide ore.

Ball mill
A large steel cylinder containing steel balls into which crushed ore is fed. The ball mill is rotated, causing the balls to cascade and grind the ore.

Bench
Successive steps/horizontal increments mined as an open pit progresses deeper.

By-product
A secondary metal or mineral product recovered in the milling process such as copper and silver.

Carbonaceous
Containing carbon or coal, especially shale or other rock containing small particles of carbon distributed throughout the mass.

Carbon-in-leach (C-I-L)
A process step wherein granular activated carbon particles much larger than the ground ore particles are introduced into the ore pulp. Cyanide leaching and precious metals adsorption onto the activated carbon occurs simultaneously. The loaded activated carbon is mechanically screened to separate it from the barren pulp, processed to remove the precious metals and finally prepared for reuse.

Carbon-in-pulp (C-I-P)
A precious metals leaching technique in which granular activated carbon particles much larger than the ground ore particles are added to the cyanidation pulp after the precious metals have been solubilized. The activated carbon and pulp are agitated together to enable the solubilized precious metals to become adsorbed onto the activated carbon. The loaded activated carbon is mechanically screened to separate it from the barren pulp, processed to remove the precious metals and finally prepared for reuse.

Concentrate
A very fine, powder-like product containing the valuable ore mineral from which most of the waste mineral has been eliminated.

Contained ounces
Represents ounces in the ground before reduction of ounces not able to be recovered by the applicable metallurgical process.

Contango
The positive difference between the spot market gold price and the forward market gold price. It is often expressed as an interest rate quoted with reference to the difference between inter-bank deposit rates and gold lease rates.

Crushing and grinding
The process by which ore is broken into small pieces to prepare it for further processing.

Cyanidation
A method of extracting gold or silver by dissolving it in a weak solution of sodium cyanide.

Deferred stripping costs
Mining costs associated with waste rock removal that are deferred and amortized to operating costs over the life of an open pit mine.

Development
Work carried out for the purpose of opening up a mineral deposit. In an underground mine this includes shaft sinking, crosscutting, drifting and raising. In an open pit mine, development includes the removal of overburden.

Dilution
The effect of waste or low-grade ore which is unavoidably included in the mined ore, lowering the recovered grade.

Doré
Unrefined gold and silver bullion bars usually consisting of approximately 90 percent precious metals that will be further refined to almost pure metal.

Drift
A horizontal tunnel generally driven alongside an ore deposit, from a shaft, to gain access to the deposit.

Drilling
Core: drilling with a hollow bit with a diamond cutting rim to produce a cylindrical core that is used for geological study and assays. Used in mineral exploration.

Reverse circulation: drilling that produces rock chips rather than core. The chips are forced by air to surface through a double-walled drill pipe and are collected for examination.

Conventional rotary: drilling that produces rock chips similar to reverse circulation except that the sample is collected through a single-walled drill pipe.

In-fill: any method of drilling intervals between existing holes, used to provide greater geological detail and to help establish reserve estimates.

Geotechnical: diamond drilling targeted and utilized specifically for the collection of information used for mine stability purposes.

Exploration
Prospecting, sampling, mapping, diamond-drilling and other work involved in searching for ore.

Flotation
A process by which some mineral particles are induced to become attached to bubbles and float, and other particles to sink, so that the valuable minerals are concentrated and separated from the uneconomic or valueless gangue or waste.

Grade
The amount of metal in each ton of ore, expressed as troy ounces per ton or grams per tonne for precious metals and as a percentage for most other metals.

Cut-off grade: the minimum metal grade at which an orebody can be economically mined (used in the calculation of ore reserves).

Mill-head grade: metal content of mined ore going into a mill for processing.

Recovered grade: actual metal content of ore determined after processing.

Reserve grade: estimated metal content of an orebody, based on reserve calculations.

Heap leaching
A process whereby gold is extracted by “heaping” broken ore on sloping impermeable pads and continually applying to the heaps a weak cyanide solution which dissolves the contained gold. The gold-laden solution is then collected for gold recovery.

Layback
A single cut, in an open pit, consisting of a number of benches, mined to expose the underlying orebody.

LIBOR
The London Inter-Bank Offered Rate for deposits.

Lode
A mineral deposit, consisting of a zone of veins, veinlets or disseminations, in consolidated rock as opposed to a placer deposit.

Long-hole open stoping
A method of underground mining involving the drilling of holes up to 30 meters or longer into an ore bearing zone and then blasting a slice of rock which falls into an open space. The broken rock is extracted and the resulting open chamber is not immediately filled with supporting material.

Metric conversion
Troy ounces × 31.10348 = Grams
Troy ounces per short ton × 34.28600 = Grams per tonne
Tons × 0.90718 = Tonnes
Feet × 0.30480 = Meters
Miles × 1.60930 = Kilometers
Acres × 0.40468 = Hectares
Fahrenheit (°F-32) × 5 ? 9 = Celsius

Mill
A processing facility where ore is finely ground and thereafter undergoes physical or chemical treatment to extract the valuable metals.

Mineral reserve
See “Narrative Description of the Business – Gold Mineral Reserves and Mineral Resources.”

Mineral resource
See “Narrative Description of the Business – Gold Mineral Reserves and Mineral Resources.”

Mining claim
That portion of applicable mineral lands that a party has staked or marked out in accordance with applicable mining laws to acquire the right to explore for and exploit the minerals under the surface.

Net profits interest royalty
A royalty based on the profit remaining after recapture of certain operating, capital and other costs.

Net smelter return royalty
A royalty based on a percentage of valuable minerals produced with settlement made either in kind or in currency based on the spot sale proceeds received less all of the offsite smelting, refining and transportation costs associated with the purification of the economic metals.

Open pit
A mine where the minerals are mined entirely from the surface.

Ore
Rock, generally containing metallic or non-metallic minerals, which can be mined and processed at a profit.

Orebody
A sufficiently large amount of ore that can be mined economically.

Ounces
Troy ounces of a fineness of 999.9 parts per 1,000 parts.

Oxide ore
Mineralized rock in which some of the original minerals have been oxidized. Oxidation tends to make the ore more amenable to cyanide solutions so that minute particles of gold will be readily dissolved.

Qualified Person
See “Scientific and Technical Information”.

Ramp
An inclined underground tunnel that provides access to and throughout an orebody for exploration, ventilation or exploitation purposes in an underground mine.

Reclamation
The process by which lands disturbed as a result of mining activity are modified to support beneficial land use. Reclamation activity may include the removal of buildings, equipment, machinery and other physical remnants of mining, closure of tailings storage facilities, leach pads and other mine features, and contouring, covering and re-vegetation of waste rock and other disturbed areas.

Reclamation and Closure Costs
The cost of reclamation plus other costs, including without limitation certain personnel costs, insurance, property holding costs such as taxes, rental and claim fees, and community programs associated with closing an operating mine.

Recovery rate
A term used in process metallurgy to indicate the proportion of valuable material physically recovered in the processing of ore. It is generally stated as a percentage of the material recovered compared to the total material originally present.

Reef
A South African term for a continuous mineral deposit, especially gold-bearing quartz.

Refining
The final stage of metal production in which impurities are removed from the molten metal.

Refractory material
Gold mineralized material in which the gold is not amenable to recovery by conventional cyanide methods without any pre-treatment. The refractory nature can be either silica or sulphide encapsulation of the gold or the presence of naturally occurring carbons which reduce gold recovery.

Roasting
The treatment of ore by heat and air, or oxygen enriched air, in order to remove sulphur, carbon, antimony or arsenic.

Semi-autogenous grinding (SAG)
A method of grinding rock into fine sand, in which the grinding media consist of larger chunks of rock and steel balls.

Shaft
A vertical passageway to an underground mine for ventilation, moving personnel, equipment, supplies and material including ore and waste rock.

Stope
An area in an underground mine where ore is mined.

Strike length
The longest horizontal dimension of an orebody or zone of mineralization.

Tailings
The material that remains after all economically and technically recoverable precious metals have been removed from the ore during processing.

Tailings storage facility
A natural or man-made confined area suitable for depositing the material that remains after the treatment of ore.

Tons
Short tons (2,000 pounds).

Total cash costs
Total cash costs are calculated in accordance with The Gold Institute Production Cost Standard and include site costs for all mining (excluding deferred stripping costs), processing and administration, royalties and production taxes, but are exclusive of amortization, reclamation, financing costs, capital costs and exploration costs. See “Non-GAAP Performance Measures”.