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Dr Gavin M Mudd Institute for Sustainable Water Resources (Civil Eng). Sustainable Mining : An Evaluation of Changing Ore Grades and Waste Volumes. Agricola (1556) :.
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Dr Gavin M MuddInstitute for Sustainable Water Resources (Civil Eng) Sustainable Mining : An Evaluation of Changing Ore Grades and Waste Volumes
Agricola (1556) : “… the strongest argument of the detractors is that the fields are devastated by mining operations … Also they argue that the woods and groves are cut down, for there is need of an endless amount of wood for timbers, machines, and the smelting of metals. And when the woods and groves are felled, then are exterminated the beasts and birds, very many of which furnish a pleasant and agreeable food for man. Further, when the ores are washed, the water which has been used poisons the brooks and streams, and either destroys the fish or drives them away. Therefore the inhabitants of these regions, on account of the devastation of their fields, woods, groves, brooks and rivers, find great difficulty in procuring the necessaries of life … Thus it is said, it is clear to all that there is greater detriment from mining than the value of the metals which the mining produces.”
Sustainable Mining ? • Debate about the impact of mining is old indeed : debate is healthy • There is now renewed debate about, termed “sustainable mining” • But what is this concept ? • Need to look at history of mining and mineral production
Presentation Outline • Mining and milling ‘101’ • Data : From production to sustainability • Mining industry position • Trends in Australian mineral production • Future directions & needs
Mining & Milling ‘101’ • Essentially, ore with the mineral of interest is excavated from the earth, processed, refined and ‘consumed’ • Ore grades vary widely, eg. : Gold ~2 g/t Iron ~60% Copper ~2% • Excavation may be underground or open cut • ‘Solution Mining’ is also used (small though)
Data : From Production to Sustainability • To assess the production performance of a mine plus the sustainability of the mining industry, various data needs include : • mining data, esp. %open cut v underground • MUST include waste rock (AMD ?) • ore milled (recovery?) – impurities (As, Hg?) • water & energy use & management • extent & success of rehabilitation • emissions (eg. greenhouse gases) • Most of this data is already collected
Mining Industry :Reporting & Sustainability • In Australia, the mining industry now has a voluntary code for environmental matters • Many companies now publish annual environment reports under this code (increasingly including social issues) • Globally, as part of the 2002 WSSD, the mining industry published the ‘Minerals Mining & Sustainable Development’ (or MMSD) reports – acknowledging many major issues facing the industry
Mining : Some Key Issues • Some of the major issues facing the future of mining include : • Declining ore grades • Increasing waste rock / tailings volumes • Resources versus depletion • Land use / conservation • Extrapolating rehabilitation performance • These and other issues all affect the overall sustainability of mining
Australian Mining Industry :Compiling the Production History • To assess the trends in ore grades and waste rock, a detailed compilation of mineral production in Australia was undertaken, including : • Ore milled – Ore grade • Production – Waste rock • Open cut v underground mining
Data Gaps & Future Directions :Towards Sustainable Mining • Some mining companies do report wide-ranging mining-milling data - many do not • To be meaningful, all relevant data should be publicly reported by mining companies and collated on an industry basis • The “environmental burden” of modern mining is increasing per unit of production • Mining’s “sustainability” – depends on ones’ perspective : jury still out
Acknowledgements • Numerous state Mines’ departments, libraries, mining companies, some consultants and several other people have helped with the research to date • Mineral Policy Institute (Sydney, NSW)
