Abstract: An improved hydrometallurgical process for the recovery of metallic copper, elemental sulfur, compounds of molybdenum and other valuable materials from copper sulfide ore concentrates, such as chalcopyrite. The process, comprising a reduction stage, metallic copper recovery stage, and a combined regeneration-purge-oxidation stage, is improved by the addition of a second reduction stage following the first or primary reduction stage, and by the addition of a by-product recovery stage after the second or secondary reduction stage. The secondary reduction stage also enhances overall process performance by allowing more flexible operating practices.

Abstract: Cuprous chloride, which is contained in a reduced leach solution or pregnant liquor, can be recovered as a complex salt of alkali metal chloride, such as potassium chloride, or alkaline earth metal chloride or ammonium chloride. The salts are produced by oxidation of a copper ore, such as chalcopyrite, with ferric chloride and cupric chloride, and after removal of insolubles, by adding sufficient metallic copper to the solution to reduce cupric ions to cuprous ions so as to provide a solution containing 1.5 to 2.5 molal potassium chloride, or other metal or ammonium chloride, and cooling the resultant saturated solution to precipitate the potassium chloride-cuprous chloride complex salts and recovering the complex salts. Also provided as a method for recovery of pure copper metal by electrolysis of solutions derived from the complex salts wherein the impurities are diverted to an anode loop which is separated from the cathode loop by a diaphragm.

Abstract: Cuprous chloride, which is contained in a reduced leach solution or pregnant liquor, can be recovered as a complex salt of alkali metal chloride, such as potassium chloride, or alkaline earth metal chloride or ammonium chloride. The salts are produced by oxidation of a copper ore, such as chalcopyrite, with ferric chloride and cupric chloride, and after removal of insolubles, by adding sufficient metallic copper to the solution to reduce cupric ions to cuprous ions so as to provide a solution containing 1.5 to 2.5 molal potassium chloride, or other metal or ammonium chloride, and cooling the resultant saturated solution to precipitate the potassium chloride-cuprous chloride complex salts and recovering the complex salts. Also provided as a method for recovery of pure copper metal by electrolysis of solutions derived from the complex salts wherein the impurities are diverted to an anode loop which is separated from the cathode loop by a diaphragm.

Abstract: A process is described for recovering metal values from a zinc-containing complex sulphide material comprising leaching the material in a first leaching stage under non-oxidative conditions with a controlled amount of an aqueous chloride lixiviant solution containing cupric chloride in an amount which is selected so as to solubilize at least a part of the zinc in the material and to precipitate a quantity of cupric sulphide substantially equivalent on a molar basis to the zinc leached from the material, the lixiviant solution further containing sufficient of a source of chloride ions other than cupric chloride to ensure solubilization of metal chlorides present, recovering from the first leaching stage a zinc chloride-containing leach liquor, recovering metal values from said leach liquor in a metal recovery section, treating solids from the first leaching stage under oxidizing conditions in a second leaching stage with a liquor containing hydrochloric acid and metal chlorides thereby to solubilize further me