Research into the possibility of air separation of cake at the Pavlodar aluminum smelter

Abstract

Air separation can play a key role in the sintering process of the charge material in the alumina production at the Pavlodar Aluminum Plant. During sintering, sinter dust is formed, which must be effectively separated from the bulk material, since its fine fraction is a source of formation of a solid phase carried away with the solution, which increases the number of secondary losses of valuable components. The use of air separation will solve this problem, providing a high degree of separation of the sinter product into coarse and fine fractions, thereby intensifying the further process of hydrochemical processing of the sinter from the sintering furnaces. The main goal of these studies was to reduce the loss of valuable components from the sinter, namely aluminum oxides and alkali, which are carried away with the solid phase of the tubular apparatus effluent. This paper considers the preliminary classification of sinter dust in air separators and its separate leaching. Extensive (pilot) laboratory tests determined the separation boundary of sinter classes (– 0.25 mm), which allows increasing alumina extraction by ~ 2% and suggests a reduction in the number of operating furnace lines by 0.26 units by reducing ballast flows, and the optimal indicator of air separation efficiency was determined to be ~ up to 97%. The results demonstrate the importance of air separation in ensuring the quality of the sinter product and improving the efficiency of alumina production technology as a whole.