An investigation of mercury stabilization techniques through hypochlorite leaching and thiosulfate/selenosulfate precipitation

The aim of this work was to develop a hydrometallurgical (or wet) technique to convert elemental mercury to stable compounds by 1) dissolving mercury in aqueous hypochlorite media, and 2) precipitating mercury as mercury sulfide or mercury selenide through controlled reaction with aqueous thiosulfate or selenosulfate ion. Different parameters such as pH, temperature, reagent concentration and rate of agitation in hypochlorite oxidation, thiosulfate precipitation and selenosulfate precipitation were studied and are reported in this work. Very stable precipitates of mercury may be formed by these methods.