Recovery of copper and zinc from complex chloride solutions
AssigneeCanadian Patents and Development Limited
InventorsGordon M. Ritcey, Kenneth T. Price, Bernard H. Lucas
Life of this patent
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Abstract
The solvent extraction separation and recovery of copper and zinc from complex chloride liquors; e.g. those resulting from the low temperature chlorination and leach of a copper-lead-zinc sulphide ore or concentrate; are described, including the selection of sequence, conditions, extractants, scrubbing and stripping media and adaptations for electrowinning and recycle. High purity copper sulphate and zinc chloride electrolytes are produced for subsequent direct electrowinning. Lead may also be recovered.
Claims16
A process for separating and recovering copper and zinc from aqueous chloride solutions containing lead, copper, zinc and impurities, comprising:
- (a) separating lead from the aqueous chloride solution by at least one of crystallization, precipitation, and solvent extraction;
- (b) solvent extracting the resulting aqueous solution with a first water-immiscible organic liquid comprising a copper-chelating extractant reagent to load copper into the organic phase;
- (c) scrubbing the Cu-loaded organic phase with at least one aqueous liquid selected from water and Na.sub.2 SO.sub.4 solution to remove impurities;
- (d) stripping the Cu from this first organic phase with aqueous CuSO.sub.4 -H.sub.4 SO.sub.4 solution and passing the Cu-containing sulphate strip solution to a Cu electrowinning stage;
- (e) scrubbing this stripped organic phase with water to remove sulphate, and recycling this organic liquid to extraction stage (b);
- (f) solvent extracting the remaining aqueous chloride solution with a second water-immiscible organic liquid comprising tributylphosphate to load zinc thereon;
- (g) scrubbing the Zn-loaded organic phase with aqueous ZnCl.sub.2 -NaCl solution to remove impurities;
- (h) stripping the Zn from this second organic phase with aqueous ZnCl.sub.2 -HCl solution and passing the Zn-containing chloride strip solution to a Zn electrowinning stage;
- and
- (i) separating impurities from the residual aqueous phase sufficiently to avoid detrimental build-up thereof, and recovering chloride solution for recycle.
Dependencies are inferred from the claim text.