Krasnoturinsk branch of Federal State Autonomous Educational Institution of Higher Professional Education «Ural Federal University named after the first President of Russia B. N. Yeltsin»

M. V. Belousov, Senior Lecturer, e-mail: MetAlMg@yandex.ru

D. F. Rakipov, Assistant Professor

E. A. Nikonenko, Assistant Professor

M. P. Kolesnikova, Assistant Professor

Magnesium production by silicothermal method is constantly increasing in the world. Here we present the research results of dolomite thermal dissociation of Boytsovsk and Chernorechensk deposits of the Middle Ural region. The research is carried out using modern methods of thermal X-ray analysis, as well as thermogravimetric, differential-thermal analysis. Mechanism of dolomite ore thermal dissociation is defined and it coincides with the dissociation mechanism of coarse-crystalline dolomite. It is established that dolomite decomposition is taking place in two stages which were registered in the temperature intervals of 733–813, 877–969 ^оС correspondingly. There were defined two points at which the process of dolomite dissociation takes place with the maximum velocity: the first is at 770 ^оС and the second is at 925 ^оС for Chernorechensk dolomite, and the temperatures of 790 and 930 ^оС correspondingly show this for Boitsovsk dolomite deposit. The research carried out showed no formation of solid solutions. Due to peculiarity of magnesium production by silicothermal method, dolomite baking was being conducted till complete decomposition of carbonates and СО₂ elimination. It is established that carbonates are dissociated completely in the temperature range 970–980 ^оС. The results of thermal X-ray analysis of dolomite ore confirm the data obtained by thermogravimetric differential-thermal analysis. The results obtained during the research enable us to carry out thermodynamic analysis of the process of dolomite thermal dissociation and to define the temperature required to carry out commercial baking of dolomite of Boitsovsk and Chernorechensk deposits with the purpose of full decomposition of carbonates and СО₂ elimination.

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