Preparation of zinc electrolytes

Claim 1

IN A METHOD OF ELECTROWINNING ZINC INVOLVING ELECTROLYZING A ZINC SULFATE ELECTROLYTE WITH AN INSOLUBLE ANODE, AND CYCLICALLY REFORTIFYING THE SPENT ELECTROLYTE FROM THE ELECTROLYSIS AND REMOVING DISSOLVED IRON FROM THE REFORTIFIED ELECTROLYTE UNDER NON-REDUCING CONDITIONS BY A PROCEDURE INVOLVING LEACHING AN OXIDIC ZINCIFEROUS MATERIAL WITH SAID SPENT ELECTROLYTE TO REFORTIFY THE LATTER, PARTIALLY NEUTRALIXING THE REFORTIFIED SOLUTION WHILE OXIDIZING FERROUS IRON THEREIN TO THE FERRIC STATE TO PRECIPITATE THE IORN CONTAINED IN THE SOLUTION WITHOUT SUBSTANTIAL PRECIPITATION OF DISSOLVED ZINC, AND FILTERING THE REFORTIFIED SOLUTION TO SEPARATE THEREFROM THE THUS PERCIPITATED IRON, SAID PARTIALLY NEUTRALIZED SOLUTION BEING CHARATERZIED BY VARIATIONS IN ITS FILTERING RATE, THE IMPROVEMENT COMPRISING INTRODUCING A SOLUBLE PENTAVALENT ARSENATE COMPOUND AT A POINT IN SAID PROCEDURE AFTER SAID ELECTROLYSIS STEP AND PRIOR TO SAID FILTRATION STEP THEREBY REDUCING CARIATONS IN THR FILTERING RATE OF THE PARTIALLY NEUTRALIZED SOLUTION AND THE NET FILTERING TIME THEREOF.