Methods and compositions for stripping nickel

Claim 1

A NICKEL STRIPPING COMPOSITION FOR USE IN AQUEOUS SOLUTION, WHICH CONTAINS ESSENTIALLY OF: (A) AN OXIDIZER SELECTED FROM THE GROUP CONSISTING OF THE SODIUM, POTASSIUM, CALCIUM AND LITHIUM SALTS OF HYPOCHLORITE, NORMAL CHLORITE, BROMATE AND HYPOBROMITE; (B) A NICKEL-COMPLEXING AGENT SELECTED FROM THE GROUP CONSISTING OF AMMONIA AND AMMONIUM CARBONATE, CHLORIDE, FLUORIDE, PHOSPHATE, SULFATE, NITRATE AND ACETATE; ETHYLENEDIAMINE, ETHLENEDIAMINE TETRAACETIC ACID; NITRILOTRIACETIC ACID; GLYCINE, GLYCOLIC, GLUCONIC AND TARTARIC ACIDS WITH SALTS THEREOF; AND (C) A DIVALENT SULFUR ION-SUPPLYING COMPOUND AS A NICKEL-ACTIVATING AGENT, SAID COMPOUND BEING SELECTED FROM THE GROUP CONSISTING OF SODIUM, POTASSIUM, CALCIUM BARIUM, MAGNESIUM, ALUMINUM AMMONIUM, HYDROGEN SULFIDES AND CARBON DISULFIDE; THIOCYANATES, THIOACETATES, THIOAMIDES, THIOANLIDS, THIOCARBAMIDES AND THE SALTS THEREOF; SAID OXIDIZER BEING PRESENT IN AMOUNT TO PROVIDE IN SOLUTION FROM ABOUT 0.1 MOL PER LITER TO NEAR SATURATION; SAID COMPLEXING AGENT BEING PRESENT IN A MOL RATIO OF AT LEAST 1:1 RELATIVE TO THE NICKEL TO BE DISSOLVED; AND SAID ACTIATING AGENT BEING PRESENT IN SMALL BUT EFFECTIVE AMOUNT UP TO ABOUT 0.23 MOL PER LITER.