Satbayev University, «Institute of Metallurgy and Ore Beneficiation» JSC (Almaty, Kazakhstan):

Abdulvaliev R. A., Head of Laboratory, Candidate of Engineering Sciences, rin-abd@mail.ru
Gladyshev S. V., Leading Researcher, Candidate of Engineering Sciences, gladyshev.sergey55@mail
Kenzhaliev B. K., General Director, Doctor of Engineering Sciences
Imangalieva L. A., Leading Engineer, l.imangalieva@imio.kz

Studies have been carried out to identify a streamlined method and conditions for melting the iron-bearing fraction of bauxite from the Pavlodar aluminum smelter (PAS). Based on an analysis of pyrometallurgical processing of red mud, the bloomery process was selected for the manufacture of cast iron from iron sands in tube-type rotary furnaces, which enables melting at lower temperatures. Before melting with a reducing agent, the sands were leached with the caustic module of a_c = 30 at 240 °C and with the addition of CaO in the amount for which the maximum recovery of Al₂O₃ into the solution was set at 50.2 % by the results of complex processing. The leaching process yielded hydrogarnet slimes, which were melted after the briquetting at 1300, 1350, and 1400 °C with a reducing agent and the duration of 60 minutes. The sintered material obtained at 1300 and 1350 °C contained no reduced iron particles, and subsequent magnetic separation rendered no separation into the magnetic and nonmagnetic fractions. The sintered material obtained at 1400 °C yielded reduced iron in the form of bloomery iron with particle sizes up to 5 mm and barren slag. In terms of the content of restrictive components (P < 0.01, S < 0.002, Si = 2.3), the composition of cast iron corresponds to grade L4 (GOST 4832-95). The recovery of iron into cast iron amounted to 99.4 % of its initial content in the iron sands. The yield of cast iron was 46.4 % of the weight of the hydrogarnet slime and 40.35 % of the weight of the charge.
The work was completed with the financial support of the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan under targeted funding program No. BR05236406.

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