Application of cupric or ferric ions as environmentally benign oxidants to the chloride leaching of platinum from spent reforming catalysts.
J Environ Manage
; 337: 117768, 2023 Jul 01.
Article
em En
| MEDLINE
| ID: mdl-36963178
ABSTRACT
Recovery of precious metals has been considered due to their limited availability and resources, and the reduction of environmental hazards. In this study, the environmentally friendly chloride leaching method was used to recover platinum (Pt) from a spent reforming catalyst. Hydrochloric acid and sodium chloride were applied as the complexing agent and ferric or cupric chloride (FeCl3, CuCl2) was used as oxidants. Response surface methodology was implemented to investigate the influences of acid concentration (1-3 M), oxidant concentration (0.5-1.3 M), and temperature (70-90 °C) on the Pt extraction at a fixed duration of 3 h using two separate Box-Behnken experimental designs. Increasing temperature and acid concentration improved the Pt recovery from â¼52% to â¼89% in the presence of 1 M FeCl3, and from â¼29% to 94% in the presence of 0.75 M CuCl2. Generally, at low acid concentrations, ferric chloride was more efficient in Pt dissolution, while, at high acid concentrations, cupric chloride performed better. Finally, the platinum content of the pregnant leach solution was precipitated by adding a saturated ammonium chloride solution. According to the results of the X-ray diffraction analysis, the obtained precipitate was mainly composed of ammonium hexachloroplatinate, sodium chloride, and ammonium chloride. Also, the Pt assay of the powder was determined as 21%.
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Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Platina
/
Cloretos
Idioma:
En
Revista:
J Environ Manage
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Irã