the drc copper belt includes some of the highest grade copper deposits in the world. in some reserves the grades are above 5%. the ore also has high grades of cobalt and may hold 34% of the world's cobalt reserves.
porphyry copper ore deposits are formed by concentration of copper within a granite stock during the ascent and crystallisation of a magma. chalcopyrite in this environment is produced by concentration within a magmatic system. chalcopyrite is an accessory mineral in kambalda type komatiitic nickel ore deposits, formed from an immiscible .
the lead–zinc concentrator could treat the copper ore with little modification, but the lead smelter required the addition of second-hand equipment lying idle at the kuridala, mount cuthbert and mount elliott mines. lead smelting ceased on 9 april 1943 and sintering of copper concentrate commenced on the same day.
the international copper study group icsg is an intergovernmental organisation of copper producing and consuming states that functions as the international commodity board for copper. its main purpose is to increase copper market transparency and promote international discussions and cooperation on issues related to copper.
in the bullion fire assay process, a sample from the article is wrapped in a lead foil with copper and silver. the wrapped sample, along with prepared control samples, heated at 1650 f temperature varies with exact method in a cupel made of compressed bone ash or magnesium oxide powder. base metals oxidize and absorb into the cupel.
a number of copper mines also contained a notable amount of silver, both in native form and naturally alloyed with the copper. halfbreed is the term for an ore sample that contains the pure copper and pure silver in the same piece of rock; it is only found in the native copper deposits of the upper peninsula of michigan. native american mining