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IH 2010-001 Reply Impacts of Gold Extraction in the EU

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IH 2010-001 Reply Impacts of Gold Extraction in the EU European Commission (EUROSTAT) Eurostat 50304.2009.001-2009.846 Information Hub Enquiry 2010-001 Impacts of Gold Extraction In the EU April 2nd , 2010 Contact Bio Intelligence Service S.A.S. Shailendra Mudgal – Louise Slater ℡ + 33 (0) 1 56 20 28 98 [email protected] [email protected] Disclaimer: The project team does not accept any liability for any direct or indirect damage resulting from the use of this report or its content. This report contains the results of research by the authors and is not to be perceived as the opinion of the European Commission. European Commission - EUROSTAT 2 April 2010 Information Hub – Impacts of Gold Extraction in the EU Contents 1. CONTEXT ................................................................................................................... 5 1.1. Background of gold extraction ................................................................................... 5 1. 1. 1. Cyanidation and gold extraction methods ................................................................... 5 1. 1. 2. Terminology .................................................................................................................. 6 1.2. Impacts of cyanide on human health and the environment ........................................ 6 1. 2. 1. Toxicity and health impacts of cyanide compounds .................................................... 6 1. 2. 2. Environmental impacts of cyanide ............................................................................... 7 1.3. EU cyanide disasters and subsequent legislation ........................................................ 8 1. 3. 1. EU cyanide accidents .................................................................................................... 8 1. 3. 2. EU Mining Waste Directive ........................................................................................... 9 1. 3. 3. EU legislation on cyanide............................................................................................ 10 1. 3. 4. EU cyanide bans ......................................................................................................... 11 1.4. Objectives of the report............................................................................................ 12 2. ECONOMICS OF GOLD IN THE EU .............................................................................. 13 2.1. Gold production in the EU ........................................................................................ 13 2. 1. 1. EU gold mining production compared to world production ...................................... 13 2. 1. 2. Main EU gold producers ............................................................................................. 14 2.2. Gold consumption in the EU ..................................................................................... 15 2. 2. 1. Financial services and monetary exchange ................................................................ 15 2. 2. 2. Jewellery ..................................................................................................................... 15 2. 2. 3. Industry and electronics ............................................................................................. 15 2. 2. 4. Dentistry ..................................................................................................................... 16 2. 2. 5. Medicine ..................................................................................................................... 16 2. 2. 6. Food and drink ............................................................................................................ 17 2.3. Gold trade in the EU ................................................................................................. 17 2. 3. 1. Gold imports ............................................................................................................... 17 2. 3. 2. Gold exports ............................................................................................................... 20 2.4. Gold recycling in the EU ............................................................................................ 20 2. 4. 1. Sources of gold ........................................................................................................... 21 2. 4. 2. Recycling potential in the EU ...................................................................................... 21 2. 4. 3. Reworking of mines .................................................................................................... 22 2.5. Possible economic consequences of a ban on gold extraction activities in the EU ....... 23 European Commission - EUROSTAT April 2010 3 Information Hub – Impacts of Gold Extraction in the EU 2. 5. 1. EU gold mines using cyanide ...................................................................................... 23 2. 5. 2. The NGO perspective ................................................................................................. 23 2. 5. 3. The industry perspective ............................................................................................ 24 3. GOLD EXTRACTION TECHNIQUES .............................................................................. 25 3.1. Gold leaching using conventional cyanidation: Best available techniques .................. 25 3. 1. 1. BATs for gold leaching using cyanide ......................................................................... 26 3. 1. 2. Minimising cyanide addition ...................................................................................... 27 3.2. Gold leaching using alternative reagents to cyanide ................................................. 27 3. 2. 1. Thiosystem (thiosulphate, thiourea, thiocyanate)..................................................... 30 3. 2. 2. Polysulphide system ................................................................................................... 30 3. 2. 3. Ammonia system........................................................................................................ 31 3. 2. 4. Halide system (chlorine, bromine and iodine) ........................................................... 31 3. 2. 5. Bio-leaching ................................................................................................................ 34 3. 2. 6. New research ............................................................................................................. 35 3.3. Carbon-extraction processing ................................................................................... 36 3. 3. 1. Carbon in column ....................................................................................................... 36 3. 3. 2. Carbon in leach .......................................................................................................... 37 3. 3. 3. Carbon in pulp ............................................................................................................ 37 3.4. Environmental protection: cyanide destruction, recycling and remediation ............... 38 3. 4. 1. Cyanide destruction ................................................................................................... 38 3. 4. 2. Recycling using membrane technology ..................................................................... 38 3. 4. 3. Recycling using ion exchange resins .......................................................................... 39 3. 4. 4. Phytoremediation of contaminated soils, sediments and water............................... 39 4. CONCLUSIONS AND RECOMMENDATIONS ................................................................ 41 4.1. Alternatives to cyanidation ...................................................................................... 41 4.2. Costs of extractive techniques .................................................................................. 41 4.3. Recommendations ................................................................................................... 43 European Commission - EUROSTAT 4 April 2010 Information Hub – Impacts of Gold Extraction in the EU 1. CONTEXT 1.1. BACKGROUND OF GOLD EXTRACTION 1. 1. 1. CYANIDATION AND GOLD EXTRACTION METHODS Leaching with sodium cyanide (cyanidation) is currently the most widely used method for gold processing operations because of its availability, effectiveness, and economics. More than half of all gold and silver mines in the world rely on the use of cyanide. First used on a large scale in the 1970s, cyanide heap leaching allows miners to extract microscopic gold flecks from low-grade ore. In a typical heap leach operation, vast quantities of rock are crushed and piled onto clay and plastic liners in huge decks. A sodium cyanide solution is sprayed onto the mound, passes through the rock layers, and in doing so extracts the gold out of the ore. Up to 97% of the gold is thus extracted, enabling the most microscopic bits of gold to be extracted from low grade ore 1. The technique of open leaching is not used in Europe however, and should not be recommended, because of the potential impacts on human health and the environment (see section 1.2). At least three main types of gold extraction methods exist and are used worldwide 2: • Pretreatment of refractory gold ore: Bacterial oxidation Pressure oxidation Roasting Emerging technologies: thiosulphate leaching, resin-in-pulp, Augment, the Albion process, Activox and others. • Leaching: Conventional cyanidation, 1) Using agitated pachuca
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