Abstract: A method of recovering copper from a copper bearing sulphide mineral which includes the steps of subjecting the slurry to a bioleaching process, supplying a feed gas which contains in excess of 21% oxygen by volume, to the slurry, and recovering copper from a bioleach residue of the bioleaching process.

Abstract: A process for recovering nickel and copper from a concentrate which includes the steps of subjecting the concentrate to a treatment phase to produce a first leach solution which contains predominantly copper and a second leach solution which contains predominantly nickel, subjecting the first leach solution to a process for copper recovery which includes a solvent extraction step to produce a raffinate which is high in sulphuric acid, recycling at least a portion of the raffinate to the aforementioned treatment phase and subjecting the second leach solution to a process for nickel.

Abstract: A process for the recovery of copper and nickel from a copper and nickel sulphide concentrate in slurry form. The slurry is subjected to a biological oxidation turning the copper sulphide to soluble copper sulphate and the nickel to nickel sulphate. The liquid containing the sulphates is separated from the slurry and treated with a solvent extraction reagent so that copper ions are exchanged by the reagent for hydrogen ions to produce a raffinate which is high in sulphuric acid and low in copper sulphate. The solvent extraction reagent is then stripped from the raffinate with a sulphuric acid solution. Copper is electrically harvested from the sulphuric acid solution and a portion of the copper depleted raffinate is returned to form a slurry with additional ore for subsequent biological oxidation. Nickel is recovered from the remaining portion of the raffinate.