Comparison of liquid–liquid extraction studies on platinum(IV) from acidic solutions using bis(2,4,4-trimethylpentyl) monothiophosphinic acid

Modified leaf biomass for Pb(II) removal from aqueous solution: Application of response surface methodology

“…The treatment of heavy metals bearing effluents has been studied by several methods such as solvent extraction, reduction, precipitation, ion-exchange, electro-chemical reduction, evaporation, precipitation, reverse-osmosis and adsorption (Mc Donald et al, 1996;Kumar et al, 2008). Among these existing methods adsorption has becoming the most popular and effective technique due to its better performance, availability of various adsorbents, ease of handling, low cost, low sludge generation, short operation time, and no production of secondary compounds which might be toxic (Ramakul et al, 2012).…”

Recovery of platinum from spent catalysts by liquid–liquid extraction in chloride medium

“…Some extractants for platinum from spent samples or standard chloride solutions have been reported in the last years, but these extractants fall into only two basic groups: (i) organophosphorus compounds such as tributyl phosphate (TBP) [16], 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC-88A) [17], try-octyl phosphine oxide (Cyanex 921) [6,18] and bis(2,2,4-trimethyl-pentyl)monothiophosphinic acid (Cyanex 302) [19]; (ii) amines such as tri-octyl/decylamine (Alamine 308) [15], tri-octyl/decylamine (Alamine 336), [16,20] mixtures of trioctylamine and tridecylamine [21] and ammonium quaternary salts such as Aliquat 336 [22]. Amines are of interest because Pt can be extracted without the interference of metals such as Fe and Al [15,20].…”

Liquid–liquid extraction/separation of platinum(IV) and rhodium(III) from acidic chloride solutions using tri-iso-octylamine

“…The extraction mechanism corresponds to an anion exchange, in which a complex of stoichiometric formula (R 3 NH + ) 2 PtCl 6 2− is formed in the organic phase liberating at the same time Cl − ions in the aqueous phase [9]. Some extractants are reported for extraction separation of platinum from palladium [10][11][12][13][14][15][16][17][18][19][20] but very less number of extractants is utilized for separation of platinum from rhodium [21,22]. The LLE literatures reviewed showed that, despite a large number of studies, no system has been identified as yet to yield quantitative extraction of rhodium from concentrated solutions [23][24][25][26][27].…”