Abstract: A method of adaptation of a bacterial culture, the method comprising the method steps of: Exposing the bacterial culture to increasing levels of pH over a period of time. A leaching process is also described.

Abstract: A leach process (70) comprising the following steps: i) Passing a metal containing waste material (72) from a mineral processing operation (96) to a biological leach step (74) in which a proportion of the metal is extracted into a pregnant leach solution (76); and ii) Passing the pregnant leach solution (76) from step i) to downstream metal recovery.

Abstract: A process for the heap leaching of multiple ores, the process characterized by the process steps of: (i) the agglomeration or wetting of an ore feed; (ii) exposing the agglomerated or wetted ore to an inoculum containing one or more bacterial species capable of biooxidizing sulphide minerals in that ore; (iii) forming one or more heaps from the ore of step (ii); (iv) dispersing further bacterial inoculum over at least a portion of the or each heap; and (v) recovering leach solution draining from the heap and passing a portion thereof to a means for metal recovery.

Abstract: A process for the heap leaching of multiple ores, the process characterized by the process steps of: (i) the agglomeration or wetting of an ore feed; (ii) exposing the agglomerated or wetted ore to an inoculum containing one or more bacterial species capable of biooxidizing sulphide minerals in that ore; (iii) forming one or more heaps from the ore of step (ii); (iv) dispersing further bacterial inoculum over at least a portion of the or each heap; and (v) recovering leach solution draining from the heap and passing a portion thereof to a means for metal recovery.

Abstract: A process for bacterial oxidation of sulphide ores and concentrates in which the ore or concentrate is leached with a bacterial culture containing one or more strains of both Sulfobacillus and Thermoplasma.

Abstract: An improved heap leach process for the bacterial heap leaching of base metal sulphide ores, the process including the addition of elemental sulphur to the ore, whereby sulphur oxidising bacteria indigenous to, or added to, the ore may oxidise the elemental sulphur and generate heat within the ore heap.

Abstract: A method for the bacterially assisted heap leaching of chalcopyrite includes providing a chalcopyrite containing ore heap to oxidize sulphide minerals therein, the heap containing and/or being inoculated with a sulphide oxidizing bacterial culture that either does not oxidize ferrous to ferric, or is inefficient at doing so. At least a first leach solution pond (or other suitable container) is provided, from which feed solution is fed to the heap, and which receives leach solution from the heap. A portion of the leach solution is bled and passed to metals recovery.

Abstract: A bacterially assisted heap leach characterized by the steps of: providing an ore heap to oxidize sulphide minerals therein; providing a biological contactor inoculated with ferrous iron oxidizing bacteria; providing at least one leach solution pond to feed solution to, and receive leach solution from both the heaps; and bleeding a portion of the leach solution and passing same to a means for metals recovery.