Patent ID: 11572605

Abstract:
A process for leaching a mineral particulate material comprising the steps of feeding the mineral particulate material to a leaching step (10) in which at least one valuable metal in the mineral particulate material is leached into a leach solution to form a pregnant leach liquor and a solid residue containing undissolved mineral matter, the leaching step being conducted under conditions such that elemental sulphur is formed in the leaching step, wherein beads or particles that take up elemental sulphur are added to the leaching step such that elemental sulphur is taken up by or collects on the beads or particles, and separating the beads or particles from the pregnant leach liquor and the solid residue. The beads or particles may be treated to remove sulphur and the beads or particles are returned to the leaching step. Alternatively the mineral doesn't need to comprise a soluble component and can be a refractory sulphide of iron and/or arsenic containing precious metals that require oxidation before downstream conventional processes such as cyanidation.