FERROALLOY FROM CHROMIUM PLATING SLUDGE WASTE

SLUDGE WASTE CONTAINING CR(VI) FROM CHROMIUM PLATING OPERATIONS IS CLASSIFIED AS HAZARDOUS AND ITS DISPOSAL IS A MAJOR CONCERN. IT CAN BE RECOVERED FOR FUTURE METAL USE IN REMELTING OPERATIONS, CAN BE STORED, OR CAN BE DISPOSED AFTER MODIFICATION TO A LEGALLY ACCEPTABLE FORM. IN PHASE I, THE CONVERSION OF SLUDGE WASTE FROM CHROMIUM PLATING OPERATIONS INTO FERROCHROMIUM ALLOYS IS PROPOSED. BY MEANS OF AN ALUMINOTHERMIC REACTION IN AN INERT ATMOSPHERE UNDER A CALCIUM OXIDE AND ALUMINA SLAG, CHROMIUM HYDROUS OXIDES FROM SLUDGES WILL BE REACTED WITH ALUMINUM POWDER, IRON OXIDE AND CARBON. THE REACTION PARAMETERS WILL BE DETERMINED USING STATISTICAL EXPERIMENTAL DESIGNS AND RESPONSE SURFACE ANALYSIS TO MAXIMIZE YIELD AND MINIMIZE SLAG INCLUSION IN INGOTS. THE PRODUCT WILL BE CAST INTO FERROCHROMIUM INGOTS FOR USE AS AN ALLOYING ADDITIVE IN THE CAST IRON AND STAINLESS STEEL FOUNDRY INDUSTRIES. THE FERROCHROMIUM PRODUCT PROCESS HAS THE POTENTIAL TO RECYCLE A CONSIDERABLE QUANTITY OF THE CHROMIUM PLATING SLUDGE WASTE CURRENTLYBEING GENERATED AND DISCARDED NATIONALLY, AND TO RETURN IT IN AN ECONOMIC AND USABLE PRODUCT FORM TO FOUNDRIES. SINCE PLATING COMPANIES MUST CURRENTLY PAY TO DISPOSE OF THIS WASTE, THE PROPOSED PROCESS THAT CAN TURN THIS WASTE INTO A SOURCE OF ECONOMIC GAIN FOR BOTH PLATER AND STEELMAKER IS HIGHLY ATTRACTIVE.