Mining for Closure: Policies, practises and guidelines for sustainable mining and closure of mines

glossary of mining/environment terminology

respiration. Liberated when vegetablematter rots, burns and when oil and gas are burnt. Bound when plants grow.

For the context of this report, the following definitions are provided for general mining and minerals sector related terminology: Acid Deposition The falling of acids and acid-forming compounds from the atmosphere to the Earth’s surface. Acid deposition is commonly known as acid rain, a term that refers only to wet deposition of droplets of acids and acid-forming compounds. Acid deposition includes the fallout of dry acid-forming compounds. Acid Drainage Also referred to as Acid Mine Drainage (AMD) or Acid Rock Drainage (ARD). Acid drainage arises from the rapid oxidation of sulphide minerals and often oc- curs when such minerals are exposed to the atmosphere by excavation from the earth’s crust. Incident rainfall or surface water is acidified when acid-forming compounds dissolve. Effects include acid drainage fromwaste rock stockpiles and tailings, development of acid conditions in exposed surface materials, increased solubility and or release of metals, and increased salinity or solute loads in waters. Acidic Water Referring to water with a pH below 7 but generally referring to pH values of 4 and below. Any water solution where the concentration of hydrogen ions (H+) is greater than the concentration of hydroxide ions (OH-). Aquifer Porous, water-saturated layers of sand, gravel, or bed rock that can yield an economically significant amount of water. Backfill Material used to fill areas in underground mines made void by the extraction of ore. This material generally comprises coarse sand, rock and cement. Bioavailability A measure of the availability (number of available pathways for exposure) for toxic substances (such as certain metallic compounds) to contact and af- fect humans, fauna or flora. Biodiversity Variety of different species (species diversity), genetic variability among individuals within each species (genetic diversity), and variety of ecosystems (ecological diversity). BOD Biological Oxygen Demand Amount of dissolved ox- ygen needed by aerobic decomposers to break down the organic material in a given volume of water at a certain temperature over a specified time period. Beneficiation The process of separation of an ore mineral from the waste mineral material.

Chlorofluorocarbons (CFCs) Abbreviation for various chemical compounds containing chlorine, fluorine and carbon. CFCs are produced in industrial processes, con- tribute to ozone layer depletion and are green house gases in the lower levels of the atmosphere. COD, Chemical Oxygen Demand An indicator of the poten- tial environmental impact of effluents to water. The COD is a laboratory measure of the quantity of oxygen required to oxidise the constituents of a liquid effluent. The lower the COD, the lower the potential for reduction in the concen- tration of dissolved oxygen in the receiving water. Concentrate Concentrate is the product of ore treatment and contains metal at a higher concentration than the source ore. In metallurgical processes for the production of nickel and copper, concentrate is smelted to produce a metallic compound suitable for further refining. Cuttings Earth and rock removed during a drilling opera- tion to make an exploration hole. Cuttings are invariably contaminated with oil from drilling fluids (oil based and other muds). Discharge This is used as a general term for all releases of contaminants into the environment, be they gas, liquid, or solid, or a combination thereof. The term “emission is used exclusively for releases in the atmosphere, “effluent” is restricted to releases into surface waters and “waste” is used for remaining releases, such as disposal to landfill or treatment by incineration. A contaminant is a compound which is present in the environment in concentrations higher than the background level, but not necessarily causing a negative impact.

Environmental Audit A programme to evaluate compli- ance with regulations, systems, programs and policies

Environmental Compliance When an organization is in strict compliance with an environmental law(s), regula- tion, or other regulatory condition imposed on an opera- tion via a licence, approval, consent, environmental im- pact assessment or other regulatory process.

Fauna Animal life characteristic of a particular region or environment.

Flora Plant life characteristic of a specific geographic re- gion or environment.

Carbon Dioxide (CO2) A colourless, odourless, tasteless gas, approximately 1.5 times the density of air. The basis for plant

Greenhouse Effect Warming of the lower level of the atmosphere (troposphere) as a result of heat radiating

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MINING FOR CLOSURE