Recuperação de ouro e prata em resíduo de joalheria em escala laboratorial a partir de processos hidrometalúrgicos com ácido nítrico, água régia e solvente orgânico acidificado

Abstract

Precious metals have been desired by humanity since its beginning, having a strong connection with the economy and monetary policies of the societies that inhabited and still inhabit the planet. Jewelry is one of the economic sectors that makes extensive use of gold and silver, therefore, its wastes are a material with great potential for recovering of these metals. This study sought to obtain jewelry polishing wastes in different shops to verify the possibility of recovering silver using nitric acid leaching and the possibility of recovering gold using two different methods: aqua regia leaching and acidified organic solvent leaching, and also verify the purity of recovered metals with SEM-EDS. All methods were able to extract the desired metals in some quantity, although most did not performed as high as reported in the bibliography. Even so, one of the samples resulted in silver chloride with a high degree of purity and two of the samples resulted in gold with a purity degree higher than 95.0%, by the leaching with aqua regia, showing how this method stands above the alternative technique of acidified organic solvent.