Comprehensive processing of converter slag

Abstract

At the present time actually all plants changed over to autogenous melting of copper-containing concentrates use the flotation of converter slags (CS) dropping in tails about 0.55-0.90 % Cu; it is higher than copper content in commercial ore. The most part of iron, zinc, lead, and silicate component of CS is also dropping with flotation tails. The concentrate resulted from converter slag (CCS) contains magnetite and this fact affects negatively on running of smelt-furnace; moreover at magnetic separation of resulted concentrate a certain part of copper is dropping too. Goal of this work is to develop pyrometallurgical technique of CS processing with its complete utilization. The methodology of studies is to implement the crucible melting to select best parameters of reduction melting of burden material based on CCS. The technological solution of two-stage process has been shown: during the first stage at temperatures 1250-1300 ^оC copper is separated to metallized middling product and slag composition is corrected; the latter at the second stage – at temperatures 1450-1500 ^оC, it is used for iron reduction with subsequent iron conversion into pig iron. The technique permits utilize completely all slag components. So 95 % of copper moves to metallized alloy, the slag of second stage of reduction contains only 0.02 % Cu, 2-5 % Fe, and 0.2 % of sulfur. Copper-containing alloys go to conversion; lead and zinc pass to fumes. Resulted demetallized slag can use in construction products. Moreover, the hot slag after second stage of degrading can use as excellent flux for conversion; it is particularly true in reprocessing of rich mattes to produce blister copper since this process runs with heavy heat balance.