Abstract: The present invention discloses a new process for leaching sulfide minerals consisting of leaching crushed ore in a vat reactor, wherein the leaching solution is fed with an ORP value close to the upper limit suitable for leaching and the exiting leaching solution leaves the reactor with an ORP above the lower limit suitable for leaching the ore. The output leaching solution that leaves the leaching reactor goes through an iron oxidation stage outside the leaching reactor, with the iron oxidation producing soluble ferric sulfate that is mixed with a recirculated portion of the output leaching solution to increase its ORP up to a value close to the upper limit of the redox potential range that is suitable for the ore leaching.

Abstract: Small magnetic particles are introduced into a solution which is subjected to a bioleaching process. The particles are coated with a substance which has a selective affinity for, and which interacts with, a metal in the solution. The particles are taken from the solution and the metal is recovered from the particles.

Abstract: A heap bioleaching process wherein carbon, in the form of a carbonate, carbon dioxide or organic carbon, is added to the heap when the temperature in the heap is in the range of 45° C. to 60° C. to increase microbial activity and thereby raise the heap temperature to about 60° C.

Abstract: A method for optimizing a bioleaching process, at least in respect of heat generation and primary copper sulphide leaching, by actively monitoring and controlling inorganic and organic compounds in a raffinate solution, produced in the process, to levels below that which could be inhibitory to microbial activity of bioleaching strains used in the process.

Abstract: Small magnetic particles are introduced into a solution which is subjected to a bioleaching process. The particles are coated with a substance which has a selective affinity for, and which interacts with, a metal in the solution. The particles are taken from the solution and the metal is recovered from the particles.

Abstract: A heap bioleaching process wherein carbon, in the form of a carbonate, carbon dioxide or organic carbon, is added to the heap when the temperature in the heap is in the range of 45° C. to 60° C. to increase microbial activity and thereby raise the heap temperature to about 60° C.

Abstract: A method of operating a tank bioleaching process of a concentrate, which includes the step of supplying carbon in a non-gaseous form to microbial cells used in the process.

Abstract: A method of heap leaching wherein a gaseous suspension which contains a microbial inoculum or nutrients is introduced into the heap.

Abstract: A method of recovering microbial cells in a bioleaching process which includes the steps of subjecting a slurry produced in a bioleaching plant to a solid/liquid separation process, and extracting microbial cells from the resulting liquid.

Abstract: A method of producing bioproducts which includes the steps of establishing an environment wherein microorganisms oxidise a slurry containing metal sulphide minerals, supplying a feed gas containing in excess of 21% oxygen by volume to the slurry, and extracting bioproducts from the slurry.