Vìsnik Odesʹkogo Nacìonalʹnogo Unìversitetu: Hìmìâ (May 2017)
THIN EMULSIFIED SOLUTIONS OF TRIALKYLAMINE IN KEROSENE AS COLLECTORS FOR FLOTATION–EXTRACTION OF THORIUM (VI) COMPOUNDS
Abstract
The principle possibility of using the thin emulsified solutions of trialkylamine in kerosene as collector of thorium compounds for their flotation extraction has been established. The colloid- chemical properties of the collector water emulsions were defined. The average radius of the emulsion droplets is equal to 1.36·10-7 m, and their electrokinetic potential is equal to +38 mV. The optimal conditions of thorium compounds flotation-extraction process have been determined. These are temperature 293 K, the initial thorium concentration 20 mg/dm3, collector consumption 2 mol TAA/mol Th, flotation time 15 min. The degree of thorium removal is 98%, the degree of emulsions dispersed phase removal is 96% under optimal conditions for floatation-extraction. The kinetics of flotation-extraction is described by the first-order equation. The rate constants and apparent activation energy of flotation-extraction process have been calculated in the temperature range 29-323 K. The rate constants are equal to (3.0-10.5)∙10-4 s-1 and apparent activation energy is equal to 33 kJ/mol. Тhe interaction mechanism for of thorium compounds with the collector at different pH has been proposed. According to this mechanism the thorium compounds such as [ThSO4]2+, [Th( SO4)2]0, [Th(OH)3] +, Th(OH)4, interact with the amino groups of trialkylamine and naphthenic acids of kerosene both on the surface and in the volume of the collector emulsions droplets.
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