EARTH

[2801-14-11] Tellurium recovery from semiconductor solid waste by means of Liquid-liquid-powder extraction

○Josiane PONOU¹, Gjergj Dodbiba¹, Toyohisa Fujita¹ (1. The University of Tokyo)

司会（Chairman）：Dodbiba Gjergj（University of Tokyo）, Shuji Owada (Waseda University)

キーワード：liquid-liquid-powder extraction, blast powder, semiconductor solid waste, Tellurium, oil droplet

Liquid-liquid-powder extraction (LLPE) is the process of transferring fine solid particles from one liquid phase to another immiscible liquid in contact with the first across the liquid-liquid boundary using surface active agent as collector. LLPE has been applied to semiconductor fine solid waste, called "Blast powder" to extract Tellurium particles from Al using dodecyl amine acetate (DAA) as collector (surfactant), kerosene as an organic liquid and ion-exchange water as aqueous liquid.
The effect of pH with respect to Al and Te concentration shows different separation patterns and indicated pH=10 as an optimum one to collect Al in water phase and Te in kerosene phase. Further experiments related to DAA dosage at pH=10 indicated that the extraction rate of Te decreases with increasing DAA dosage pointed out 0.05% of DAA dosage as an optimum one to collect 65.13±1.33% of Te in kerosene phase. Therefore, with the optimum conditions of pH=10, DAA dosage of 0.05% the grade of the blast powder in terms of Te shifts from 7.70±0.43% to 25.24±0.67% and in terms of Al shifts from 52.24±1.73% to 9.15±1.50% indicated the high separation efficiency of Te and Al and also the concentration of Te in the final product.