En effet il y a des gisements de Cuivre qui ont en "prime" un peu d' Or, mais ou exploiter l' Or seul ne serait pas rentable (trop peu concentré).
Par exemple le minier Freeport exploite en Indonésie du Cuivre dans du minerai à 1% de Cuivre et ..... 1.1 gramme d' Or par tonne !
L' Or est peu concentré, mais les gisements trés vastes, de sorte que des millions d' once d' Or peuvent étre récupérés chaque année.
http://www.mineweb.net/mineweb/view/min ... tail&pid=1
et au Canada (en Colombie Britannique) il y un projet d' explotation de Cuivre à seulement 0.18% et un infime 0.33 gramme d' Or par tonne.Copper bottom for global gold mining
As new pure gold resources become scarcer, gold mining majors are increasingly trending to developing large copper/gold deposits.
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One of the largest porphyry mines is Freeport McMoRan's 90%-owned Grasberg mine, in Indonesia, which milled at an average rate of 238,000 t/d last year. This mine is relatively rich with average grades of 0.98 % copper and 1.1 g/t gold in 2009 and produced 1.64 Blb of copper and 2.98 Moz of gold in the year.
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Bon, .... tout ca demande une énergie bon marché, sinon adieu veaux vache cochons .........
Sticking with the copper/gold porphyry theme, one region where such deposits abound is Canada's British Columbia province, another region within the geologically active Pacific Rim, and here there are signs that a softer Provincial government stance may lead to the eventual development of some of the well-defined projects there. Most recently, a junior company, Terrane Metals, received approval to build a mine at its Mt Milligan project. Mt Milligan hosts resources of 7.5 Moz of gold and 2.8 Blb of copper but at grades of only 0.33 g/t gold and 0.18% copper. Goldcorp holds almost 60% of the equity of Terrane.
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