Recovering and recycling Hg from Chlor-Alkali plant wastewater sludge

摘要

Montana Tech of the University of Montana and Universal Dynamics of British Columbia have developed a hydrometallurgical process for recovering and recycling mercury from chlorine plant wastewater sludge materials (U.S. Environmental Protection Agency [EPA]hazardous-waste classification K106). The hydrometallurgical process is also applicable for the treatment of mercury-contaminated soils (EPA hazardous waste classification D009) and other mercury-bearing waste materials. The process, which is capable of lowering the mercury content in the K106 solids from 10% to <50mg/kg Hg, has been commercialized and utilized at three U.S. plants. This paper describes the fundamental chemistry of the process, the flowsheet being used, and operating plant case histories.