Mixed copper sulphide oxide ores

Mixed copper sulphide oxide ores. These contain varieties of both sulphide and oxide minerals, and are the most complex copper-bearing ores from a beneficiation point of view. The major copper minerals present in this ore type include bomite, chalcocite, covellite, malachite, cuprite and chrysocolla. In some cases, significant amounts of cobalt minerals are also present in this ore. 

This method is the most commonly used in beneficiation if oxide copper-bearing ore. The reagent schemes used to treat oxide copper ores, mixed copper sulphide oxide ores and oxide copper cobalt ores varies from one ore type to the next, mainly by type of collector and sulphidizer used. 

The plant metallurgical results achieved in these concentrators are presented in Table 19.12. In most cases, the results obtained on mixed copper sulphide oxide ores are better than those obtained on oxide ores. The floatability of oxide copper from mixed ore is usually better than the floatability of copper from oxide ores. 

Plant results from mixed copper sulphide oxide ores... 

The mixed sulphide oxide ores usually contain two or more oxide minerals, including cuprite, malachite and tenanntite. The sulphide copper minerals are represented by covellite and bomite. Examples of this type of operation are located in the former Republic of Zaire (Komoto, Dima 1 and 2 plants), and the Nchanga open pit plant in Zambia. 

In general, the reagent schemes used in these plants depend largely on the type of ore being treated. The following sections describe the operating practices of the major plants that treat oxide and mixed oxide sulphide copper ores. 

Hydrometallurgical methods can be applied when low-grade oxidized (oxide) or mixed (oxidized and sulphidic) ores are available. These methods have advantages of high selectivity disadvantages are the relative slowness of leaching and the large volume of solution per unit mass of copper. 

Tenorite (CuO Cu = 80%, SG = 6.5) is usually present in mixed copper oxide and sulphide ore. The flotation properties of tenorite are similar to that of cuprite. 

Most operating plants that treat oxide copper and copper-cobalt ores are found in Central Africa and Southern Africa regions. A few operations exist in Chile, Brazil and Peru, where they treat mixed oxide sulphide ores or oxide copper gold ore. 

MM. Hallett and Btetthousis process —A natural oxide of antimony, or an ore in which the sulphide and the oxide are associated together, is used. The mineral is pulverised and is separated from the gangue by washing or by some mechanical device. The heavy portion thus obtained is calcined in a reverberatory furnace, and from it the sulphur is driven off as sulphuric acid. The residue consists mostly of antimonious acid, which, after being further powdered, is mixed with oil or varnish. The product may occasionally contain a little lead, copper, or iron, which has the effect of diminishing its whiteness. Hence it is mostly used for inferior painting. 

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