The determination of residual anionic surface-active reagents in mineral flotation liquors

Abstract

A method is described for the determination of residual amounts of anionic surface-active reagents, used as flotation promoters, in mineral flotation liquors. The method is equally effective for the long carbon chain carboxylates and the anionic non-soapy surface-active agents. The reagent used is the cationic copper(II) triethylenetetramine complex, which reacts in alkaline solution with anionic surface-active agents to give an adduct that can be extracted into an isobutanol-cyclohexane mixture. The copper associated with the surface-active anion in the extract is determined photo-metrically as the coloured complex using diethylammonium diethyldithiocarbamate. Long chain carboxylates with carbon numbers from C₁₄ to C₂₂, as well as anionic non-soapy surface-active reagents, can be determined in the range 0·2 to 10 p.p.m. The effect of a number of likely interferences has been investigated.