Technology demonstration for reducing mercury emissions from small-scale gold refining facilities.

Abstract

Gold that is brought from artisanal and small-scale gold mining areas to gold shops for processing and sale typically contains 5-40% mercury. The uncontrolled removal of the residual mercury in gold shops by using high-temperature evaporation can be a significant source of mercury emissions in urban areas where the shops are located. Emissions from gold shop hoods during a burn can exceed 1,000 mg/m 3. Because the saturation concentration of mercury vapor at operating temperatures at the hood exhaust is less than 100 mg/m 3 , the dominant component of the exhaust is in the form of aerosol or liquid particles.

Policies and regulations for Brazil’s artisanal gold mining sector: analysis and recommendations

“…The retort promoted by the GMP, as mentioned in Sousa and Veiga (2009), had an efficiency of 90% according to tests performed by the local supplier ("CIMAQ da Amazonia"). Moreover, the fume hood developed by the USEPA (United States Environmental Protection Agency), as also described by Sousa and Veiga (2009), presented an efficiency of 80%, as demonstrated by Habegger et al (2008).…”

International guidelines on mercury management in small-scale gold mining

“…4 The guidelines address both mercury in gold mines as well as in gold shops, and it should be noted that a significant amount of research and experimentation has recently gone into designing and building fumehoods and condenser/filter systems for gold shops; some designs are discussed by Habegger et al (2008) in the context of a collaboration between the Global Mercury Project and the United States Environmental Protection Agency [72]. While solutions to technical challenges in the field require discussions with miners and gold shops operators, in many cases, the guidelines themselves do leave much to the imagination and should provide grounds for asking questions such as: What should miners or gold shop owners do with recycled mercury?…”