Mercury Leaching Behavior from Sulfurized and Solidified Waste Mercury under Alkaline Condition

Abstract

The Minamata Convention on Mercury has come into effect in August 2017. As a result, intermediate treatment of waste mercury and waste mercury compounds is obligatory for "purification, sulfurization, and solidification," and it is essential to evaluate the long-term stability of waste mercury in final disposal facilities. In this resarch, we conducted a series of leaching tests to clarify the pH dependence of mercury leaching from mercury sulfide (HgS) and sulfurized and solidified waste mercury under alkaline conditions. It was indicated that the mercury leaching characteristics of HgS differed depending on the degree of sulfurization. The mercury containment effect of the solidification treatment with modified sulfur was demonstrated up to around pH 13 for waste mercury. It was suggested that the modified sulfur solidification can be suppressed.