The use of an intermediate temperature (the spouted bed temperature) permits to improve the efficiency of metal separation from dusts injected in a plasma jet.
It is shown experimentally that separation of metals from a dust conaining Pb, Sn, As, Zn and In is affected by the oxygen partial pressure in the plasma jet, and by spouted bed temperature.
Under oxidizing and CO/C02 conditions in the jet, the best results have been obtained with a high bed temperature (1250K). Under reducing conditions (Ar-H2), the separation index of Indium exhibits a maximum at 930K bed temperature. A vapor containing respectively 6 and 4 times the In and As initial concentrations is collected in the fume, whereas the concentrations of Zn and Sn decrease 3 times.