Separation of platinum(IV) and palladium(II) from concentrated hydrochloric acid solutions by mixtures of amines with neutral extractants

Abstract

Separation of platinum and palladium from concentrated HCl solutions by extraction with mixture of amines (Aliquat 336/Alamine 336/TOA) and neutral extractants (TBP/TOP/MIBK) have been investigated. The mixture of Aliquat 336 and TBP led to higher Pt(IV) separation factor at 6 M HCl solution. McCabe–Thiele diagram for the extraction of Pt by this mixture was constructed. Low concentration of thiourea in the HCl solution resulted in selective stripping of Pd from the loaded organic. Pt solution with 99.9% purity was obtained by extraction and stripping from the solution containing Pd. A process was proposed to separate the two metals.