Sorption recovery of platinum(II, IV) from chloride and sulfate-chloride solutions

The sorption preconcentration of platinum (II, IV) ions was investigated in presence of accompanying copper (II) and zinc (II) ions from chloride solutions on the new ion exchangers CYBBER (Russia), previously unexplored. The initial concentrations of platinum and accompanying ions were 0.25 mmol L-1 and 2.0 mmol L-1, respectively, and the acidity of medium was 0.001 - 4.0 mol L-1. It was shown that the resins investigated - strong and weak basic anion exchangers as well as chelate ion exchangers - possess good sorption and kinetic properties. The simultaneous sorption of investigated ions results in the complete recovery of platinum, while the non-ferrous metal ions are sorbed at less than 20%. Followed by the selective elution of platinum by thiourea (80 g L-1) solution in 0.3 M H2SO4, the quantitative isolation of platinum was achieved (more than 90%). Therefore, the studied ion exchangers can be recommended for recovery and separation of Pt(II,IV), Cu(II) and Zn(II) ions.

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Sorption Recovery of Platinum Metals from Production Solutions of Sulfate-Chloride Leaching of Chromite Wastes

Metals ◽

10.3390/met11040569 ◽

2021 ◽

Vol 11 (4) ◽

pp. 569

Author(s):

Georgiy Petrov ◽

Irina Zotova ◽

Tatiana Nikitina ◽

Svetlana Fokina

Keyword(s):

Ion Exchange ◽

Chloride Solution ◽

Sorption Isotherms ◽

Complete Recovery ◽

Platinum Group Metals ◽

Platinum Metals ◽

Chloride Solutions ◽

Kinetic Curves ◽

Sorption Recovery ◽

Platinum Group

This paper discusses the scientific rationale for methods of platinum metals sorption centralization from saturated solutions with a high content of macrocomponents. Methods of sorption centralization of platinum and iridium using local anionites such as AH-31, AB-17-8, Purolite S985 are described. The sorbents used were conditioned to remove organic and mineral impurities. The sorption isotherms of platinum group metals 1/EC=f(1/Cp) at a temperature of 20 °C and a duration of 24 h were plotted. The data on the sorption recovery of platinum and iridium from individual and combined sulfate-chloride solutions were determined. Isotherms of iridium sorption from sulfate-chloride solution are formed. Results of the apparent sorption equilibrium constant and values of standard Gibbs energy (ΔG, kJ/mol) of ion exchange for sorption of platinum and iridium from individual and combined sulfate-chloride solutions are presented. Linearized isotherms and kinetic curves of joint sorption of platinum and iridium from sulfate-chloride solution are described. Comparative sorption of the platinum-group metals (PGM) by anionites AB-17-8 and Purolite S985 from sulfate-chloride solutions is shown. The sorption diagram of platinum and iridium from sulfate-chloride product solutions is presented. It has been revealed that complete recovery is achieved using chelation ion-exchange resin Purolite S985, with recovery of Pt up to 95% and Ir more than 73%. The sorption process is accompanied by intradiffusion constraints that are confirmed by the analysis of kinetic curves using Schmukler and Boyd–Adams models.

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