Recycling of solids in oxidative pressure leaching of metals using halide ions

A process for improving the recovery of a precious metal from a host material comprising a base metal and the precious metal, comprising the steps of:

• subjecting the host material to an oxidative pressure leach process, in the presence of a leach solution bearing a halide ion constituent which is reactive with the precious metal and the base metal, at a temperature sufficient to cause at least a portion of the base metal and only a portion of the precious metal to be extracted into a leachate solution to provide leached solids;
• separating the leached solids from the leachate solution to provide separated leached solids;
• recovering precious metal and base metal from the leachate solution;
• and
• recycling, after separating the leached solids from the leachate solution, at least 50% of the separated leached solids comprising at least a portion of the precious metal to the oxidative pressure leach process step, so as to increase the portion of precious metal recovered from the leachate solution,
• wherein the precious metal comprises at least one of gold, platinum or palladium, and
• wherein the base metal comprises at least one of nickel, copper, zinc or cobalt.