Recovery of nickel and copper values from copper ammonium carbonate leach solutions

Claim 1

A PROCESS FOR SEPARATING AN AQUEOUS, AMMONICAL COPPER CARBONATE LEACH SOLUTION CONTAINING A MINOR PROPORTION OF NICKLE NOT EXCEEDING ABOUT 6 GRAMS PER LITER INTO A SOLID PHASE CONTAINING A HIGH NICKLE TO COPPER RATIO THAN SAID SOLUTION AND A LIQUID PHASE SUBSTANTIALLY COMPLETELY FREE FROM NICKLE, COMPRISING THE STEPS OF PREPARING AS A STARTING COMPOSITION AN AQUEOUS SOLUTION CONTAINING FROM 20 TO 100 GRAMS PER LITER OF NH3, 20 TO 80 GRAMS PER LITER OF CO2, FROM 10 TO 100 GRAMS PER LITER OF COPPER IN CUPRIC STATE AND AT LEAST 0.01 PER CENT OF NICKLE BASED UPON THE COPPER, THEREAFTER DISTILLING OFF AMMONIA TO APPROXIMATELY THE POINT OF INCIPIENT PRECIPITATION OF COPPER AND THAN REDUCING THE NH3:CO2 CONCENTRATION RATIO, WHILE MAINTAINING THE PRESSURE AT A POINT TO PREVENT PRECIPITATION OF COPPER AS OXIDE, UNTIL FROM 20 TO 50 PER CENT OF THE COPPER HAS BEEN PRECIPITATED AS BASIC COPPER CARBONATE AND SEPARATING THE RESULTING PRECIPITATE FROM THE RESULTING LIQUID PHASE WHEREBY A SUBSTANTIALLY NICKLE FREE LIQUID PHASE IS OBTAINED CONTAINING FROM 50 TO 80 PER CENT OF THE COPPER.