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

from the ground being absorbed by global warming gases.

operation via a licence, approval, consent, environmental impact assessment or other regulatory process.

Greenhouse Gases Or climate change gases, contributing to the global warming effect (carbon dioxide, methane, CFCs, ozone, dinitrogen oxide). Groundwater All water present below the ground surface. Groundwater fills the voids between soil or rock particles. Groundwater is replenished by surface water infiltration. Hazardous Material Amaterial, which as a result of its phys- ical, chemical or other properties, poses a hazard to human health or the environment when it is improperly handled, used treated, stored, disposed of, or otherwise managed. Hazardous Waste Any solid, liquid, or containerised gas that can catch fire easily, is corrosive to skin tissue of met- als, is unstable and can explode or release toxic fumes, or has harmful concentrations of one or more toxic material that can leach out. Incident An unplanned event of chain of events which has, or could have caused injury or illness and/or damage to the environment, third parties or company assets. Matte Such as nickel matte, a metallic nickel sulphide, containing approximately 75% metal. The material pro- duced by smelting a metal concentrate. Methane (CH4) A global warming gas produced by anaer- obic decay of organic material. The main component in natural gas. Is often held within coal seams. Convention- ally not included in the category of gases called volatile organic compounds. Mineral (Mineral resource) Concentration of naturally oc- curring solid, liquid, or gaseous material, in or on Earth’s crust, in such form and amount that its extraction and conversion into useful materials or items is currently or potentially profitable. Mineral resources are classified as metallic, or non-metallic. Neutral drainage A term generally referring to neutral Fe- rich water and subsequent precipitates. Acidic drainage is a common result from the exposure of sulphur con- taining coal and sulphide-bearing rocks. Acidic drainage is (generally) characterized by yellow, ferric hydroxide precipitates that drop out downstream from discharge points. However, similar precipitates also form naturally in places where Fe-bearing, anoxic (ground) waters dis- charge into streams. In these circum-neutral settings, the precipitates have red and red-orange hues. Nitrous Oxides (NOx) A general term for nitrogen oxide gases. These are generally produced by combustion proc- esses and can contribute to the formation of smog and acidification effects. Non-compliance Environmental non-compliance means to be out of strict compliance with an environmental law, regulation, or other regulatory condition imposed on an

Ore Part of a metal yielding material that can be economi- cally and legally extracted. An ore typically contains two parts: the ore mineral, which contains the desired metal, and the waste mineral material (gangue).

Overburden Soil and weathered rock which is excavated and removed to reach underlying ore.

Ozone A reactive form of oxygen. Ozone plays an impor- tant role both at ground level and in the upper atmosphere. In the upper atmosphere it acts as a filter for ultraviolet radiation but is destroyed by halogenated hydrocarbons (halons and CFCs). At ground level it is produced by reac- tions with VOCs and NOx and is a constituent of photo- chemical smog, it is an irritant, can cause breathing dif- ficulties, and can retard the growth of plants. Ozone Layer Ozone formed in the upper atmosphere (stratosphere) under the effects of solar radiation. This layer absorbs much of the harmful ultraviolet radiation and prevents it from reaching the earth’s surface. Paste Paste refers to dewatered tailings with little or no wa- ter bleed that are non-segregating in nature.The advantag- es of paste backfill over hydraulic fill include reductions in binder consumption, slimes handling, stope preparation and surface disposal together with productivity improve- ments associated with an increased mining cycle. Perfluorinated Carbon Compounds (PFCs) Also known as perfluorocarbons. Global warming gases contributed (principally) by aluminium smelting. The principal PFCs are CF4 and C2F6, their global warming potential is 6300 and 12500 CO2 equivalents respectively. While relatively small volumes are produced, a very significant environmental effect ensues. PFCs are produced during anode effects (AEs), perturbations of current flow at the anode in reduction cells. Petrochemicals Chemicals obtained by refining crude oil. Used as raw materials in the manufcture of most indus- trial chemicals, fertilisers, pesticides, plastics, synthetic fibres, paints medicine and many other products. Particulates Fine solid particles which remain individu- ally dispersed in air.

Recycling Extraction and recovery of valuable materials from scrap or used products.

Rehabilitation Treatment of disturbed areas ultimately leading to stable, vegetated land forms consistent with the previous landforms or an acceptable alternative use.

Risk – and related terms.

Risk A description of the likelihood of the harm be- coming actual. Importantly, risk is (at least) two-di- mensional and consideration of risks must encom-

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MINING FOR CLOSURE