Environmental Code of Practice for metal mines: glossary

Glossary of Terms


A substance containing hydrogen; when this substance is dissolved in water, it tends to provide hydrogen ions (protons). Or a substance having a tendency to lose protons.
Acidic drainage:
Acidic water (and possibly water that contains metal(s)) resulting from the chemical weathering of rock or soil material primarily caused by the oxidation of sulphide minerals. Also referred to as acid mine drainage ( AMD) or acid rock drainage ( ARD).


Base metals
Industrial non-ferrous (non-iron) metals excluding precious metals.
Bulk sampling
A method whereby a sample (also called a gross sample) is taken from a deposit lot for analysis. The bulk sample is intended to be representative of the deposit.


The clean or final ore product recovered in the concentration or separation stage of the milling process.
Any physical, chemical or biological substance that is introduced into the environment. Does not imply an effect. Usually refers to substances of anthropogenic origin.
A method of extracting exposed gold or silver grains from crushed or ground ore by dissolving it in a weak cyanide solution. May be carried out in tanks inside a mill or in heaps of ore out of doors.
A chemical inorganic salt of hydrocyanic acid ( HCN) used in the milling process to dissolve precious metals such as gold and silver.


Mineral deposit or ore deposit used to designate a natural occurrence of a useful mineral, or an ore, in sufficient extent and degree of concentration to invite exploitation.
The process of dissolving a solid substance into a solvent to yield a solution (a stage in leaching).


A dynamic complex of plant, animals and microorganism communities and their non-living environment interacting as a functional unit.
A complex waste material that is a by-product of human activity (i.e., liquid industrial discharge or sewage) and is discharged to the environment.
Prospecting, sampling, mapping, diamond drilling and other work involved in searching for ore. In some cases exploratory miningis conducted in whichsmall-scale mining activities are carried out to study potential ore deposits.


A milling process in which valuable mineralparticles are induced to become attached to bubbles and float as others sink.


The study of the chemical properties of rocks.
The science concerned with the study of the rocks that compose the Earth.
A hydrated calcium sulphate mineral ( CaSO4·2H2O).


A geographic area that can provide for the key activities of life.
Heavy metal
Metallic elements with relatively high atomic weights (> 5.0 specific gravity) such as lead, cadmium, arsenic and mercury. Generally toxic in relatively low concentrations to plant and animal life.
A branch of extractive metallurgy that involves the use of aqueous chemistry for the recovery of metals from ores, concentrates, and recycled or residual materials (leachingis a sub-process.)


A chemical process for the extraction of valuable minerals from ore. Also, a natural process by which groundwaters dissolve minerals, thus leaving the rock with a smaller proportion of some of the minerals than it contained originally.
The behaviour of sediments that, when loaded, suddenly go from a solid state to a liquefied state. Or having the consistency of a heavy liquid.


A facility in which ore is treated and metals are recovered or prepared for smelting. Also, a revolving drum used for the grinding of ores in preparation for treatment.
The part of the mining process by which minerals of economic value are recovered by crushing and grinding ore, by ore separation or concentration, and by dewatering the ore. The objective of milling is to separate minerals of economic value from the rock in which they occur.
A naturally occurring homogeneous substance having definite physical properties and chemical composition and, if formed under favourable conditions, a definite crystal form.
Excavation for the purpose of extracting valuable minerals from an economic ore deposit. Can be a surface or open pit mine or an underground mine.


A substance, element or compound necessary for the growth and development of plants and animals.


Open pit mining
Term used to differentiate this form of mining from extractive methods that require tunnelling into the earth. Open pit mines are used when deposits are found near the surface, where the overburden is relatively thin or the material of interest is structurally unsuitable for tunnelling. Also commonly referred to as strip mining.
A natural mineral deposit in which at least one mineral occurs in sufficient concentrations to make mining the mineral economically feasible.
Generally means the material overlying the oredeposit, including rock as well as soil and other unconsolidated (loose) materials. For this document, the term overburden is restricted to unconsolidated materials, including soil, glacial deposits, sand, and sediment.
A chemical reaction in which electrons are lost from an atom and the charge of the atom becomes more positive. Normally, oxidation involves the addition of atmospheric oxygen or water. Oxidation occurs concurrently with reduction.
Oxide minerals
A group of minerals whose fundamental unit is oxygen, O -2. The common cations in oxides include Cu +2, Mg +2, Al +3, Fe +2, Mn +2, Ti +2, Cr +2 and Sn +2.
See Oxide minerals.


A measure of the acidity or alkalinity of water, sediment or soil. The measure is based on the concentration of hydrogen ions and gives the negative logarithm of the hydrogen ( H+) ion, corresponding to 10 -7. A pH value of 7 is neutral. All values higher are considered alkaline, and all values lower are considered acidic.
Soil at or below 0°C for two or more years. Here there is not sufficient heat during the warming months to thaw the frozen soil completely. Ice may or may not be present. The active layer is the top layer of soil that thaws during the summer and freezes again during the autumn. Liquid water cannot flow below the active layer, with the result that permafrost environments tend to be very poorly drained and boggy.
The condensation of a solid from a solution (a stage in the leaching process).
A branch of extractive metallurgy consisting of the thermal treatment of minerals and metallurgical ores and concentrates to bring about physical and chemical transformations in the materials to enable the valuable metals to be recovered (smelting is a sub-process).


The process by which lands disturbed as a result of mining activity are returned to a beneficial land use. Reclamation activity may include the removal of buildings, equipment, machinery, other physical remnants of mining, closure of tailings impoundments, leach pads and other mine features, and contouring, covering and revegetating waste rock piles and other disturbed areas.
A chemical reaction in which electrons are gained by an atom and its charge becomes more negative. Reduction occurs concurrently with oxidation.


Solid fragmental material that originates from weathering of rocks and is transported or deposited by air, water or ice, or that accumulated by other processes, such as chemical precipitation from solution or secretion by organisms. The term is usually applied to material held in suspension in water or recently deposited from suspension and to all kinds of deposits, essentially of unconsolidated materials.
A fluid mixture of liquids and solids.
A sub-process of pyrometallurgy; its main use is to produce a metal from its ore. This includes the extraction of iron from iron ore (for the production of steel) and the extraction of copper and other base metals from their ores. Smelting uses heat and a chemical reducing agent, commonly a fuel that is a source of carbon such as coke, to change the oxidation state of the metal ore. The carbon or carbon monoxide derived from it removes oxygen from the ore, leaving just the metal.
A group of plants, animals or microorganisms that have a high degree of similarity and generally can interbreed only among themselves.
Sulphate mineral
A mineral characterized by the bonding of a sulphate anion with a metal such as barium, calcium, lead or copper. Sulphates may or may not include water in their structure. Common examples include barite ( BaSO4) and gypsum( CaSO4·2H2O).
See Sulphate mineral.
Sulphide mineral
A metallic mineral characterized by the covalent bonding of sulphur with a metal or semi-metal, such as iron, copper, lead, zinc, nickel or molybdenum. An example of a common sulphide mineral is pyrite, which has the chemical formula FeS2. Sulphide minerals occur in a wide range of geological environments. When occurring in sufficient concentrations, sulphide minerals can be important oreminerals for a range of base metals, including copper, lead, zinc and nickel.
See Sulphide mineral.
Suspended solids
A solid substance present in water in an undissolved state, usually contributing directly to turbidity.


The waste material and water mixture that is left over after the mill removes the valuable rocks. The rock material in tailings is usually the size of sand grains or smaller.
Tailings Management Facility
All components and facilities functionally pertaining to tailings management, including dams, spillways, decant structures, tailings lines, as well as settling and polishing ponds.
The inherent potential or capacity of a material to act on a group of selected organisms, under defined conditions. An aquatic toxicity test usually measures the proportion of organisms affected by their exposure to specific concentrations of chemical, effluent, elutriate, leachate, or receiving water.
Toxicity test
The means by which the toxicity of a chemical or other test material is determined. A toxicity test is used to measure the degree of response produced by exposure to a specific level of stimulus (or concentration of chemical).
A long, narrow excavation dug through overburden, or blasted out of rock, to expose a vein or orestructure.


Waste rock
Rock which does not contain any minerals in sufficient concentration to be considered ore, but which must be removed in the mining process to provide access to the ore.
Any water that has been adversely affected in quality by anthropogenic influence. In the case of operations at a mine or mill site, wastewater includes all water generated as part of a process prior to discharge as an effluent, including any mine and site runoff water. Domestic wastewater refers specifically to wastewater from non-industrial sources such as laundry and other wash water and sewage.
Water body
Any significant accumulation of water, including oceans, seas, lakes, ponds, wetlands, rivers, streams, canals, and other geographical features where water moves from one place to another.
Habitats where the influence of surface or groundwater has resulted in the development of plant or animal communities adapted to such aquatic or intermittently wet conditions. Wetlands include tidal flats, shallow subtidal areas, swamps, marshes, wet meadows, bogs, muskeg, and similar areas.
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