Method of producing copper metal powder

Claim 1

IN A METHOD OF PRODUCING COPPER METAL POWDER FROM AQUEOUS SOLUTIONS AND SLURRIES WHICH CONTAIN DISSOLVED SALTS OF COPPER AND AT LEAST ONE OF THE METALS OF THE GROUP CONSISTING OF NICKEL AND COBALT BY REACTING SUCH SOLUTIONS AND SLURRIES IN A REACTION VESSEL WITH A SULPHUR-FREE REDUCING GAS AT ELEVATED TEMPERATURE AND PRESSURE WHEREBY DISSOLVED COPPER VALUES ARE REDUCED TO AND PRECIPITATED FROM THE SOLUTION AS COPPER METAL POWDER; THE IMPROVEMENT WHICH COMPRISES CONDUCTING THE REDUCING REACTION IN A CYCLE OF REDUCING STEPS IN WHICH, FOLLOWING INITIAL PRECIPITATION OF COPPER METAL PARTICLES AND PRIOR TO THE FINAL STEP OF THE CYCLE, A CHARGE OF FRESH SOLUTION IS REACTED WITH SAID REDUCING GAS IN A STEP OF THE CYCLE IN THE PRESENCE OF PREVIOUSLY PRECIPITATED COPPER METAL PARTICLES UNTIL THE SOLUTION IS SUBSTANTIALLY DEPLETED OF DISSOLVED COPPER VALUES; EACH STEP OF THE CYCLE COMPRISING AGITATING AND HEATING THE CHARGE OF FRESH SOLUTION AT A TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 200* F. TO ABOUT THAT AT WHICH THE REDUCING REACTION IS CONDUCTED PRIOR TO THE INTRODUCTION OF THE REDUCING GAS UNTIL DISSOLUTION OF DISSOLVED METALS OF THE GROUP CONSISTING OF NICKEL AND COBALT IS OBTAINED; REACTING SAID SOLUTION WITH A SULPHUR-FREE REDUCING GAS UNTIL THE SOLUTION IS SUBSTANTIALLY DEPLETED IN DISSOLVED COPPER VALUES; DISCHARGING REACTED SOLUTION FROM THE REACTION VESSEL; AND, IN THE FINAL STEP OF THE CYCLE, TERMINATING THE REDUCING REACTION PRIOR TO PRECIPITATION FROM THE SOLUTION OF A METAL OF THE GROUP CONSISTING OF NICKEL AND COBALT; AND THEREAFTER SEPARATING AND RECOVERING PRODUCT COPPER METAL POWDER OF HIGH PURITY FROM THE FINAL STEP OF THE CYCLE.