A-Z of Copper Ore Leaching

Melbourne, Australiawww.altamet.com.au

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Notes: 1. A basic knowledge of the solubilities of copper minerals, and the reaction chemistry involved, lays the

foundation for the evaluation of ores for leaching. 2. A basic knowledge of the behaviour of gangue minerals in contact with the lixiviant is another key in

assessing ores for leaching. 3. CO2 can benefit bio-leaching of sulphide minerals and mixed oxide/sulphide ores, as it promotes bacterial

growth. On the debit side, release of CO2 can hinder solution percolation in heap leaching, and is a potential hazard particularly in agitated and vat leaching plants due to accumulation in enclosed and low lying areas.

4. High silica in the leach solution can cause leach solution clarification problems and phase disengagement and crud problems in associated solvent extraction facilities.

5. The presence of chloride in the leach solution above about 1 g/L can render 316 stainless steel unsuitable for use in equipment, and result in the need to use more expensive alloys. High chloride can also result in the need for additional equipment in SX to keep it out of the associated EW.

Table 2 Composition of Some Copper Oxide Minerals

MINERAL COMPOSITION %Cu SG

AZURITE 2Cu2CO3.Cu(OH)2 55.3 3.7

MALACHITE CuCO3.Cu(OH)2 57.6 3.6-4.1

CHRYSOCOLLA CuSiO3.2H2O 36.1 2-2.4

TENORITE CuO 79.7 6.5

CUPRITE Cu2O 88.8 6.1

DIOPTASE CuSiO3.H2O 40.3 3.2

BROCHANTITE CuSO4.3Cu(OH)2 56.2 4.0

ATACAMITE CuCl2.3Cu(OH)2 59.5 3.8

PSEUDO MALACHITE Cu5(PO4)2(OH)4.H2O 53.5 4.3

NATIVE COPPER Cu 100 8.96

7 A-Z of Copper Ore Leaching

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FIG. 9 SEPON FLOWSHEET (“Sepon Hydromet”, S. Keokhounsy, T. Moore and M. Liu, ALTA Copper

2006)

34 A-Z of Copper Ore Leaching

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