Detoxification of Waste Containing Mercury Using Chemical Methods

Chloro – Alkali Industry is the major consumer of mercury as these types of Industry using the conventional Mercury Cell process where a large quantity of Solid waste containing Mercury and Chlorinated mercury compounds are generated. Disposal of these solid waste are very difficult throughout the world as well as India also. Primary experiment shows that the sludge disposed by a Choloro Alkali Industry situated in West Bengal, India contain around 130 mg/kg of total mercury. To extract mercury from the sludge, chemical oxidation and complex formation to dissolve mercury in aqueous phase from brine sludge is used. From the aspects of economic consideration and effectiveness of mercury recovery, it is observed that chlorine treatment is suitable over the other. By chlorine treatment about 65% of mercury can be recovered in normal temperature from the sludge. Using Hydrochloric acid about 76% of mercury can be recovered but chlorine treatment process would be both cost effective and technically feasible for commercial purposes as Chloro – Alkali Industry produced chlorine and it is rejected as istage in the Chloro – Alkali Industry.