Abstract: Calcium (Ca), manganese (Mn) and magnesium (Mg) carbonate plus lead (Pb) and zinc (Zn) sulphide minerals in a permeable host, crushed ore, concentrates or as mine discharge tailing are selectively solution mined (in-situ or ex-situ) with a selected acid e.g. acetic acid to extract Ca, Mn, and Mg followed by multivalent oxidizing salts e.g. ferric salts to extract Pb and Zn sequentially. For in-situ leaching, an inter relationship has been identified between pressure, temperature, target depth and leachate concentration such that carbonate leaching is performed in a manner to prevent carbon dioxide gas (CO2) discharge thereby plugging host rock permeability avenues to preclude further leaching. This requires controlling the rate of acetic acid leaching to be in step with availability of solution to dissolve the resulting discharged CO2. Sulphide leaching is subsequently conducted on the carbonate-depleted host.

Abstract: Calcium (Ca), manganese (Mn) and magnesium (Mg) carbonate plus lead (Pb) and zinc (Zn) sulphide minerals in a permeable host, crushed ore, concentrates or as mine discharge tailing are selectively solution mined (in-situ or ex-situ) with a selected acid e.g. acetic acid to extract Ca, Mn, and Mg followed by multivalent oxidizing salts e.g. ferric salts to extract Pb and Zn sequentially. For in-situ leaching, an inter relationship has been identified between pressure, temperature, target depth and leachate concentration such that carbonate leaching is performed in a manner to prevent carbon dioxide gas (CO2) discharge thereby plugging host rock permeability avenues to preclude further leaching. This requires controlling the rate of acetic acid leaching to be in step with availability of solution to dissolve the resulting discharged CO2. Sulphide leaching is subsequently conducted on the carbonate-depleted host.