How to recover mercury from mercury contaminated soil

摘要

PROBLEM TO BE SOLVED: To recover by separating mercury as metallic mercury from mercury- contaminated soil by a method wherein a reaction accelerating additive of sulfides or the like of iron and peroxide are mixed in mercury-contaminated soil, the contaminated soil is treated by heating, and the removed mercury transferred into exhaust gas phase is collected as metallic mercury. SOLUTION: A reaction accelerating additive is mixed by stirring in a soil contaminated with mercury compounds, which is heated at a temperature lower than a boiling point of mercury. Thereby, mercury being generated in a gas phase is taken as metallic mercury not as a compound form, and mercury is separated by quenching the heating air. By heating by mixing sulfides of iron as the reaction accelerating agent, a sufficient removal rate can be obtained. However, since it is discharged as black mercury sulfide difficult to collect, by adding by mixing preliminarily peroxides as a metallic mercury recovery agent in heating, mercury can be recovered as the metallic mercury.