Process of separating zinc from ammoniacal solutions of copper and zinc

Claim 1

IN A PROCESS OF RECOVERING ZINC FROM ZINCIFEROUS MATERIAL CONTAINING COPPER, WHEREIN SAID MATERIAL IS LEACHED WITH AMMONIACAL-AMMONIUM CARBONATE LIQUOR TO DISSOLVE A FINITE AMOUNT OF ZINC IN A SOLUTION CONTAINING AT LEAST 20 GRAMS PER LITER OF DISSOLVED ZINC, A LARGER AMOUNT OF DISSOLVED COPPER BUT LESS THAN ABOUT FOUR TIMES THE AMOUNT OF DISSOLVED ZINC, AND NH3 IN EXCESS OF THAT REQUIRED TO HOLD SAID DISSOLVED COPPER AND DISSOLVED ZINC IN SOLUTION; THE IMPROVED METHOD OF TREATING SAID SOLUTION TO SELECTIVELY PRECIPITATE ZINC VALUES WHICH COMPRISES: OXIDIZING AT LEAST THE DISSOLVED CUPROUS COPPER IN EXCESS OF ABOUT 20 GRAMS PER LITER TO CUPRIC COPPER; HEATING RESULTANT SULTION AT FROM ABOUT 60*C. TO ABOUT 90*C. FOR SUFFICIENT TIME TO VOLATILIZE SUFFICIENT AMMONIA, CARBON DIOXIDE AND WATER VAPOR THEREFROM TO INITIATE PRECIPITATION OF WHITISH SUBSTANTIALLY COPPER-FREE ZINCIFEROUS SOLIDS; CONTINUING SAID HEATING AND PRECIPITIATION FOR SUFFICIENT TIME TO PRODUCE A RESIDUAL WEIGHT RATIO OF DISSOLVE ZINC TO DISSOLVED COPPER OF FROM ABOUT 1:4 TO ABOUT 1:8; STOPPING SAID HEATING AND COLLECTING RESULTANT PRECIPITATE IN WHICH ZINC IS SUBSTANTIALLY ONLY METAL.