Study on Application Potential of Waste Cake from Secondary Zinc Industry

Zinc extraction process generates hazardous waste cake during the recovery of electrolytic grade zinc and copper. The characteristics of the waste with reference to basic properties viz. ignitability, corrosivity, reactivity and EP toxicity are important parameters that define the magnitude of hazard of a waste. The waste under study falls under Schedule-I of Hazardous Waste (Management & Handling) Rules, 2003. The Toxicity Characteristics Leachate Procedure (TCLP) test was carried out for extraction of waste cake leachate and subsequently toxic heavy metals present in the waste were estimated. The physic-chemical parameters along with particle size analysis, differential thermal analysis and X-ray diffraction analysis were carried out which provide information on the major constituents present in the hazardous zinc waste cake before and after stabilisation/stabilisation of the waste. The approach would be helpful in safe disposal and exploring application potential of zinc waste through adoption of suitable binder mechanism.