Palladium Extraction from Nitrate Solutions with the Disulfide of Bis(2,4,4‐trimethylpentyl)dithiophosphinic Acid

Abstract

This work presents data on palladium recovery from nitrate solutions with the disulfide of bis(2,4,4‐trimethylpentyl)dithiophosphinic acid (L) in toluene. Extraction of palladium with the disulfide is slow but it increases as the concentration of L in the organic phase increases. At a concentration of L equal to 0.01 mol/L, almost complete extraction of palladium (99.7 %) is achieved within 20 minutes. The extraction efficiency also increases with increasing temperature. Maximum palladium recovery occurs at an HNO3 concentration of 1.0 mol/L in the aqueous phase. Analysis of the interphase palladium distribution showed that the extraction of palladium with the disulfide in toluene is due to the formation of the complexes of variable composition [(Pd(NO3)2)n⋅L] in the organic phase where n=1–4. The disulfide can be used to recover palladium from nitric acid solutions containing metal impurities. The degree of palladium extraction in one‐stage is 98.2 %, therefore the extractant is highly selective toward Pd(II) in the presence of Ni(II), Cu(II), Co(II), Zn(II), and Fe(III). Almost complete palladium stripping from the organic phase is achieved with a mixture of thiourea and hydrochloric acid solutions.

2-Mercaptobenzimidazole derivative of chitosan for silver sorption – Contribution of magnetite incorporation and sonication effects on enhanced metal recovery

“…However, hydrometallurgy remains one the most frequent strategies for metal recovery; involving leaching process for metal recovery from solid wastes [7,8]. The removal of metals from leachates may involve different processes such as solvent extraction [8][9][10][11][12], associated with electro-winning and redox processes [13,14], especially when the concentrations are high enough to make these processes competitive. For more dilute solutions (containing less than 200 mg Ag L −1 ), sorption processes may be more appropriate.…”