Premium
Palladium Extraction from Nitrate Solutions with the Disulfide of Bis(2,4,4‐trimethylpentyl)dithiophosphinic Acid
Author(s) -
Grigorieva Natalya A.,
Fleitlikh Isaac Y.,
Logutenko Olga A.
Publication year - 2020
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.202003660
Subject(s) - palladium , chemistry , extraction (chemistry) , nitric acid , hydrochloric acid , thiourea , inorganic chemistry , toluene , aqueous solution , nuclear chemistry , chromatography , organic chemistry , catalysis
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 HNO 3 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(NO 3 ) 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.