Solvent-in-pulp extraction of copper and nickel from ammoniacal leach slurries

DETAILED DESCRIPTION We claim: 1.
A process for the recovery of base metal values selected from the group consisting of copper and nickel from a manganese containing ore comprising introducing a stream of said manganese containing ore into a reaction vessel containing cuprous ions in an aqueous ammoniacal ammonium carbonate solution to enable the cuprous ions to reduce the manganese oxides in the ore and solubilize the metal values therein, delivering reduced manganese ore slurry from the reaction vessel to a mixer/settler, lowering the pH of the slurry to at least 10.
0, but not lower than 8.
5, maintaining the amount of solid in the slurry in the mixer at 20% by weight or less, introducing an organic extractant capable of extracting copper and nickel values from aqueous ammonical ammonium carbonate solutions at pH's between 8.
5-10 into the mixer/settler, the volume of slurry and organic extractant being maintained at a ratio so that the organic extractant in the mixer is in the continuous phase and extracting the base metal values from the slurry with the extractant, the control of pH, solid content of the slurry and mixer operation enabling metal values to be extracted from slurries with losses of organic reagents held to 100-200 parts per million.
2.
The process as set forth in claim 1 wherein an oxime extractant is introduced into the mixer/settler to extract the base metal values from the slurry.
3.
The process as set forth in claim 1 wherein the slurry and extractant are mixed in the mixer at speeds sufficiently slow so the formation of emulsions are avoided.
4.
The process as set forth in claim 3 wherein an oxime extractant is introduced into the mixer/settler to extract the base metal values from the slurry.
5.
The process as set forth in claim 3 including the step of oxidizing the slurry to convert the cuprous ions to cupric ions said oxidation being performed prior to the extracting step.
6.
The process as set forth in claim 5 wherein an oxime extractant is introduced into the mixer/settler to extract the base metal values from the slurry