A controlled dust generation whereby the dustgenerated would be enriched with specific metals wouldconsiderably facilitate the possibilities of recovering metalsfrom such dusts. A basic understanding of the dust formingmechanisms is of fundamental importance to achieve acontrolled dust generation. The present study deals with dustformation in a copper converting process. Dust samplescollected from various places in the gas cleaning system werecharacterised for chemical and mineralogical composition usingchemical analysis as well as microprobe analysis.Thermodynamic calculations were used to predict the formationof chemically formed dust at various temperatures and amountsof leakage air to the gas system. The results show that aseparation of mechanically formed dust, e.g., SiO_2, Cu andchemically formed dust, e.g., Pb, Zn, As, Bi, could, to someextent, be obtained due to their different particle sizes. Aselective condensation of Pb, Zn and As at various temperaturescould, according to thermodynamic calculations, be possible athigh temperature. A selective condensation of metals requires anairtight gas cleaning system or a gas cleaning system with alimited amount of leakage air in order to maintain the desiredtemperature level.
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