LOW Eh LEACH WITH SULFUR RECYCLE

摘要

A process for leaching nickel and/or cobalt containing laterite or partially oxidised laterite ore including the steps of : a) providing a laterite or partially oxidised laterite ore; b) leaching the ore in a leach step with an acid in the presence of a reducing agent, to produce a leach discharge containing nickel and/or cobalt values; c) recovering the nickel and/or cobalt from the leach discharge leaving a nickel and/or cobalt barren discharge liquor; and d) treating the discharge liquor to recover at least a portion of any sulfur present as sulfur dioxide and/or sulfuric acid; wherein the reducing agent is present in a sufficient amount to lower or maintain the Eh of the leach step such that the majority of the iron (III) present in the leach process is converted to the iron (II) state.