Aqueous Pretreatment Effect to Improve Au, Ag, and Pt Recovery from Spent Automotive Catalysts

Autor: Adriana Vargas, Johana Borda, Robinson Torres
Jazyk: English<br />Spanish; Castilian
Rok vydání: 2023
Předmět:
Zdroj: Revista Científica, Vol 47, Iss 2 (2023)
Druh dokumentu: article
ISSN: 23448350
0124-2253
2344-8350
DOI: 10.14483/23448350.20875
Popis: Automotive catalysts represent a secondary source for precious metals recovery. These elements are usually obtained from minerals. Recently, methods have been sought to recover them from waste materials. The main route consists of pyrometallurgical treatments at high temperatures with the generation of other pollutants and very high energy consumption. With hydrometallurgy, routes can be developed which favor the aqueous extraction of said elements at room temperature. In an automotive catalyst, there are different metals which can interfere in the recovery process. In this study, sodium citrate (Na3C6H5O7•H2O), nitric acid (HNO3), and hydrochloric acid (HCl) were evaluated as a hydrometallurgical pretreatment to dissolve Fe, Zn, and Pb contained in a spent automotive catalyst and to improve the subsequent extraction of the precious metals contained therein (Au, Ag, and Pt). Afterwards, the aqueous extraction of precious elements with thiourea (SC(NH2)2) was carried out, comparing the effect of the pretreatment reagents. Finally, the feasibility and effect of each pretreatment as a route for precious metals recovery were analyzed with the aim to avoid processes at high temperatures.
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