mercury

During the past three decades, the global mercury use has declined; there are still various major uses. One major use is in the artisanal mining of gold and silver by millions of artisanal miners across Asia, Africa, and Latin America. The amount of mercury used could be 200 to 3,000 t/yr, potentially a very large quantity. Yet this is very difficult to estimate with any certainty because there are no reliable statistics for this type of economic activity. Supply of mercury: There are five major sources of supply. First, there are industrial-scale mines that receive public subsidies, located in four countries: Spain, Algeria, Kyrgyzstan, and China. Second, there are anecdotal accounts of artisanal miners of mercury near demand “hotspots”, e.g., near artisanal gold/silver mining areas in China, Mexico, Mongolia, Peru, and Russia. Third, an increasing supply (300 t/yr) results from byproduct capture by industrial-scale metal producers (e.g., gold, silver, zinc, copper, lead, aluminum). Fourth, secondary supplies are significant, including hundreds of tons of mercury that become available after closure of a chlor-alkali factory; this may yield 500 to 1,000 tons/yr on a global basis.