US 4,097,271 AGranted

Hydrometallurgical process for recovering copper and other metal values from metal sulphides

AssigneesCominco Ltd., Sherritt Gordon Mines Limited

InventorsGodefridus M. Swinkels, Edward F. G. Milner, Roman Michael Genik-Sas-Berezowsky

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Abstract

A hydrometallurgical process for the separate recovery of non-ferrous, ferrous, and precious metal values and sulfur from metal sulfide ore concentrates by leaching of metal sulfides with a lixiviant containing ferric chloride, cupric chloride and chlorine, precipitating cuprous chloride from the leach solution with butadiene, separating and decomposing the formed addition compound to recover the cuprous chloride, oxidizing and hydrolyzing the cuprous chloride to precipitate cupric oxychloride, converting the cupric oxychloride to cupric oxide, and reducing the cupric oxide with hydrogen for the recovery of copper. The leach residue is treated for the recovery of elemental sulfur and gold. Brine solution resulting from the conversion of cupric oxychloride to cupric oxide is electrolyzed for the production of sodium hydroxide for the cupric oxychloride conversion, hydrogen for the cupric oxide reduction and chlorine, which is partly used in the recovery of gold and partly recycled to the concentrate leach. Silver is recovered as silver iodide from the mother liquor from the cuprous chloride precipitation with butadiene. A portion of the solution from the silver recovery is treated for recovery of Cu, Zn, Co and Ni, and the remaining portion and residual solution from Cu, Zn, Co and Ni recovery are treated with oxygen at elevated temperature and pressure for the regeneration of ferric chloride and precipitation of excess iron as anhydrous ferric oxide.

A process for the recovery of non-ferrous, ferrous and precious metal values and sulphur from concentrates containing metal sulphides which comprises the steps of:

(1) subjecting said concentrates to a leach at a temperature in the range of about 80.degree. to 110.degree. C under autogenous pressure with lixiviant containing ferric chloride, cupric chloride and chlorine to form a leach solution containing cuprous chloride and a leach residue;
(2) treating said leach solution with gaseous butadiene at a temperature in the range of about -35.degree. to +40.degree. C under autogenous pressure to form a precipitate of cuprous chloride-butadiene addition compound and residual solution;
(3) decomposing precipitated addition compound at a temperature of up to about 80.degree. C. at atmospheric pressure for the separate recovery of cuprous chloride and butadiene;
(4) returning recovered butadiene to step (2);
(5) slurrying recovered cuprous chloride and treating the slurry with an oxygen-bearing gas at a pressure in the range of about atmospheric to 250 psi and at a temperature in the range of about 50.degree. to 150.degree. C to form a precipitate of cupric oxychloride and a solution containing cupric chloride;
(6) returning solution containing cupric chloride to step (1);
(7) electrolyzing brine solution for formation of sodium hydroxide solution, hydrogen gas and chlorine gas;
(8) converting precipitated cupric oxychloride to cupric oxide and brine solution with an approximately stoichiometric amount of formed sodium hydroxide solution at a temperature in the range of about 80.degree. C to the boiling point of the reaction mixture, under autogenous pressure, to give a final pH in the range of 7 to 11;
(9) returning brine solution to step (7);
(10) reducing cupric oxide to metallic copper with formed hydrogen gas;
(11) passing formed chlorine gas to step (1);
(12) treating residual solution from step (2) with an oxygen-bearing gas at a partial pressure of oxygen in the range of from about 100 to 200 psi and at a temperature in the range of from about 135.degree. to 165.degree. C for the regeneration of ferric-chloride and the simultaneous precipitation of anhydrous ferric oxide;
and
(13) returning regenerated ferric chloride to step (1).

11 more elements

Abstract

Claims19