Mining terminology 101
Mineral symbols:
| Precious metals | Primary ore | Base Metals | Primary ore mineral |
| Au: Gold | Native | Cu: Copper | Chalcopyrite |
| Ag: Silver | Native | Zn: Zinc | Sphalerite |
| Pt: Platinum | Native/Sperrylite | Pb: Lead | Galena |
| Pd: Palladium | Native/Sperrylite | Mo: Molybdenum | Molybdenite |
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| Fe: Iron | Hematite/Magnetite | |
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| Ni: Nickel | Pentlandite |
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| Sn: Tin | Cassiterite |
Units/Conversion factors:
Precious metals are typically reported in grams per tonne (metric) or ounce per ton (Imperial).
Base metals are typicall reported in percantages of element within a specified amount of the ore.
OPT: ounces per ton
g/t : Grams per tonne
Terminology:
Drift
A horizontal mine working which allows access to the ore body. Also allows for transport and logistics within a mining operation.
g/t Au
Grams per tonne. 1 g/t = 0.03 OPT (ounces per ton). A measure of gold content within an ore. Signifies the average number of grams of gold (Au) contianed within one metric tonne of rock.
g/t typically used to indicate precious metal content within an ore.
OPT Au
Ounces per ton. 1 OPT = 34.2818 g/t (g/t = grams per tonne). A measure of gold content within an ore. Signifies the average number of ounces of gold (Au) contained within one imperial ton of rock.
OPT typically used to indicate precious metal content within an ore (High grade deposits).
Resuing
a. A method of stoping wherein the wall rock on one side of the vein is removed before the ore is broken. Employed on narrow veins, less than 30 in (76 cm), and yields cleaner ore than when wall and ore are broken together.
b. A method of stoping in which the ore is broken down first and then the waste or vice versa; usually the one which breaks easier is blasted first. The broken waste is left in the stope as filling, and the ore is broken down on flooring laid on the fill to prevent admixture of ore and waste. Resuing is applicable where the ore is not frozen to the walls and works best if there is considerable difference between the hardness of the ore and of the wall rocks.
- U.S. Bureau of Mines Dictionary of Mining, Mineral, and Related Terms
Shaft
a. An excavation of limited area compared with its depth; made for finding or mining ore or coal, raising water, ore, rock, or coal, hoisting and lowering workers and material, or ventilating underground workings. The term is often specif. applied to an approx. vertical shaft, as distinguished from an incline or inclined shaft. A shaft is provided with a hoisting engine at the top for handling workers, rock, and supplies; or it may be used only in connection with pumping or ventilating operations..
- U.S. Bureau of Mines Dictionary of Mining, Mineral, and Related Terms
Shrinkage stoping
A vertical, overhand mining method whereby most of the broken ore remains in the stope to form a working floor for the miners. Another reason for leaving the broken ore in the stope is to provide additional wall support until the stope is completed and ready for drawdown. Stopes are mined upward in horizontal slices. Normally, about 35% of the ore derived from the stope cuts (the swell) can be drawn off ("shrunk") as mining progresses. As a consequence, no revenues can be obtained from the ore remaining in the stope until it is finally extracted and processed for its mineral values.
The method is labor intensive and cannot be readily mechanized. It is usually applied to orebodies on narrow veins or orebodies where other methods cannot be used or might be impractical or uneconomical. The method can be easily applied to ore zones as narrow as 4 ft (1.2 m), but can also be successfully used in ore widths up to 100 ft (30 m).
- U.S. Bureau of Mines Dictionary of Mining, Mineral, and Related Terms
Stope
An area where ore has been removed or is being prepared to be remove. Sizes of stopes are related to the ore body and mining method. Access to the stopes are via the drifts.
Winze
a. A vertical opening driven downward connecting two levels in a mine. When one is standing at the top of a completed connection the opening is referred to as a winze, while when standing at the bottom, the opening is a raise, or rise. Syn:winds
b. A subsidiary shaft that starts underground. It is usually a connection between two levels.
- U.S. Bureau of Mines Dictionary of Mining, Mineral, and Related Terms
