Zh. Abishev Chemical and Metallurgical Institute (Karaganda, Kazakhstan):

E. Zh. Shabanov, Ph. D. (Metallurgy), Head of Laboratory of Ferroalloys and Reduction Processes
A. S. Baisanov, Cand. Eng., Prof., Head of Pyrometallurgical Processes Laboratory
R. T. Toleukadyr, Master, Junior Research Assistant, Laboratory of Ferroalloys and Reduction Processes, corresponding author, e-mail: ruslan-94kz@mail.ru
I. S. Inkarbekova, Master, 1^st Category Eng., Laboratory of Ferroalloys and Reduction Processes

The article presents the results of a study of phase transformations occurring during gradual heating of briquetted mono-charge. A complex of physical and chemical studies aimed at establishing the possibility of monocharge use for smelting of standard carbon ferrochromium was carried out in the laboratorial conditions on the basis of the Chemical and Metallurgical Institute named after Zh. Abishev. In order to study the phase transformations occurring in a mono-charge for smelting of high-carbon ferrochromium, thermograms of chromium briquettes of different variants were obtained in air oxidizing atmosphere and nitrogen inert atmosphere. Among them the following variants are mentioned: chromium fines mixed with a reducing agent, option I - Shubarkol coal; option II - Borlinsky coal; option III - China coke; as well as option IV - pure dust from Aktobe ferroalloy plant gas cleaning; option V - dust from pellet production site at Donskoy GOK with China coke and option VI - flash from production of briquettes with China coke. As a result of processing of thermograms, the peak temperatures and temperature intervals of behaviour of the thermal effects of chromium oxide interaction with used reducing agents were established. The method of differential thermal analysis (DTA) is based on the most important properties of a substance which are related to its chemical composition and structure and are reflected in the thermal changes of a substance when heated. The reason for the widespread use of this method of non-isothermal kinetics is that one experiment can determine all the kinetic constants, including the activation energy. Analyzing the calculated data on the activation energy, it is possible to assume the diffusion nature of inhibition of the reduction reaction for all studied chromium ore materials. Based on the values of the activation energy of the process, briquettes with Borlinsky coal and complex reducing agent have the highest reducibility.

This research was funded by the Committee of science of the Ministry of education and science of Kazakhstan Republic (Grant No. AP14871610).

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