Silver recovery from dental amalgam wastes

Abstract

Alloys produced with mercury and other metals are called amalgam Dental amalgams are important alloys and contain mercury with the addition of silver tin and copper Therefore these amalgams have high economic value and need to be evaluated This experimental study deals with recovering their metal contents by physical and chemical separation techniques Within the framework of this study distilled non contact dental amalgam wastes were subjected to size reduction leaching with nitric acid and cementation with copper Leach liquor was filtered and both solution and leach residue were characterized Results have shown that leaching efficiency was above and leach solution contained g L Ag and g L Cu ions Later silver was recovered from solution by cementation with copper The basic parameters in the cementation experiments such as cementator quantity stirring speed pH and temperature were examined Cementation efficiency reached above and chemical analysis has shown that silver concentration of solution decreased from g L to mg L