Solvent extraction of chromium(III) from alkaline media with quaternary ammonium compounds. Part I

For the first time, it has been experimentally demonstrated that hydrophobic quaternary ammonium compounds dissolved in hydrocarbons are able to effectively extract chromium(III) from alkaline aqueous solutions. Experimental investigation has been performed on extraction of chromium(III) with benzyldodecyldimethylammonium bromide (BDDMA-Br), trioctylmethylammonium chloride (TOMA-Cl) and trioctylmethylammonium hydroxide (TOMA-OH). The yield of chromium(III) extraction was studied at various contact times of the aqueous and organic phases, the composition of the phases, and ageing time of the initial aqueous phase. Under optimal conditions, the extraction of chromium(III) goes quickly with Cr(III) removal exceeding 99%.