Lipetsk State Technical University, Lipetsk, Russia

V. G. Mikhailov, Cand. Eng., Associate Prof., Dept. of Metallurgical Technologies, e-mail: valentinmikhailov@yandex.ru
A. V. Karpov, Cand. Eng., Associate Prof., Chair for Metallurgical Technologies, e-mail: antonkrpv@rambler.ru
A. A. Eremeev, Graduate Student, Dept. of Metallurgical Technologies

Converter sludge is a by-product of steelmaking and is formed in quantities of 10–30 kg/t steel. This sludge can be considered as a valuable technogenic raw material for the production of cast iron and steel and can be used as iron flux in sintering, blast furnace and steelmaking processes, since the total content of Fetot and CaO is 65–80 %, while the mass fraction of SiO₂ does not exceed 3 %. The reuse of converter sludge in metallurgical production is limited by the high zinc content (up to 4 %). The possibilities of involving converter sludge in recycling in metallurgical production are considered. The nature of the formation of converter sludge, its granulometric and mineralogical compositions are given. Examples of industrial implementation of technology for rolling various materials during the pelletizing process at sintering factories of domestic and foreign enterprises are shown. In laboratory conditions, a study was carried out of the effectiveness of rolling converter sludge (sludge was used after dehydration and drying, 26% of particles with a particle size of >2.5 mm), both separately and with additives onto the surface of pelletized granules. The sludge supply technology simulated the process of dosing it into the tail part of the pelletizing drum 30 s before the end of the pelletizing process. The greatest efficiency was achieved when using a mixture for rolling of converter sludge (75%), lime (15%) and coke (10%) in an amount of 9% of the total mass of the charge. The use of such a mixture made it possible to increase the productivity of the sintering process by 17.5% due to an increase in the vertical sintering rate, with a slight decrease in the yield of suitable agglomerate.

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