A process for the recovery of nickel and/or cobalt from an impure nickel,
cobalt or mixed nickel/cobalt material including the steps of: a)
providing a nickel, cobalt or mixed nickel/cobalt material; and b)
contacting the nickel, cobalt or mixed nickel/cobalt material with a feed
ammoniacal ammonium carbonate solution and a reductant in a leach step.