Treatment of aqueous alkali cyanide electrolytes

Claim 1

IN THE PROCESS OF TREATING AN AQUEOUS ALKALI COPPER CYANIDE ELECTROLYTE HAVING AN EXCESS OF CARBONATE, CONTAINING ORGANIC IMPURITIES AND HAVING A DEFICIENCY OF FREE ALKALI METAL CYANIDE, THE IMPROVEMENT WHICH COMPRISES ADDING TO THE AQUEOUS ELECTROLYTE A COMPOSITION COMPRISING FROM 85% TO 5% BY WEIGHT OF CALCIUM CYANIDE, AND FROM 5% TO 45% BY WEIGHT OF CALCIUM CYANIDE, AND FROM 10% TO 50% BY WEIGHT OF CALCIUM OXIDE, THE COMPOSITION BEING ADDED IN AN AMOUNT SUFFICIENT (1) TO REACT WITH ONLY THE EXCESS OF CARBONATE TO FORM A PERCIPITATE OF CALCIUM CARBONATE, THERE REMAINING AT LEAST ABOUT 4 OUNCES PER GALLON OF CARBONATE IN THE ELECTROLYTE, AND (2) TO PROVIDE ADDITIONAL FREE ALKALI METAL CYANIDE TO REMEDY THE DEFICIENTY THEREOF; AND COMPOSITION MAINTAINING THE PH OF THE AQUEOUS ELECTROLYTE AT A LEVEL OF NOT OVER SUBSTANTIALLY 16 OUNCES PER GALLON OF ALKALI HYDROXIDE TO PROMOTE THE RAPID SETTLING OF THE CALCIUM CARBONATE PRECIPITATE IN THE FORM OF A MASS OF RELATIVELY COARSE EASILY FILTERABLE PARTICLES WHICH PRECIPITATE OCCLUDES THE ORGANIC IMPURITIES IN THE ELECTROLYTE, AGITATING THE ELECTROLYTE AND THE ADDED COMPOSITION UNTIL THE PRECIPITATE-FORMING REACTION IS SUBSTANTIALLY COMPLETE AND SEPARATING THE TREATED ELECTROLYTE FROM THE PRECIPITATE.