METHOD FOR PROCESSING ELECTROPLATING SLUDGE

摘要

IMPROVED RECOVERY OF TIN FROM SLUDGE FORMED DURING A HALOGEN-TYPE ELECTROLYTIC TINPLATING OF STEEL SHEET COMPRISES LEACHING THE SLUDGE WITH WATER AT A PH OF 7 OR LESS, SEPARATING AN IRON-CONTAINING SLUDGE REMAINING AFTER THE LEACHING, ALKALIFYING THE FILTRATE OBTAINED IN THE FIRST SEPARATION STEP TO DEPOSIT TIN-CONTAINING SLUDGE, SEPARATING AND RECOVERING THE TIN-CONTAINING SLUDGE DEPOSITED IN THE FIRST ALKALIFYING STEP, REDISSOLVING THE TIN-CONTAINING SLUDGE IN AN ALKALINE SOLUTION. HIGH PURITY METALLIC TIN IS RECOVERED FROM SLUDGE, AT A HIGH YIELD. OTHER MATERIALS ARE ALSO RECOVERED FOR REUSE FROM THE FILTRATE AND PRECIPITATION, WHICH ARE FORMED DURING THE PROCESS, WITHOUT POLLUTION, WHICH ARE FORMED DURING THE PROCESS, WITHOUT POLLUTION OF THE OPERATIONAL ENVIRONMENT.