Bentonite of Khakassia Ltd., Chernogorsk, Russia¹ ; Research Institute of Comprehensive Exploitation of Mineral Resources named after Academician N. V. Melnikov of Russian Academy of Sciences (ICEMR RAS), Moscow, Russia²
D. A. Vetyugov, Mineral Processing Technologist¹, Postgraduate Student², e-mail: vetug7@gmail.com

Research Institute of Comprehensive Exploitation of Mineral Resources named after Academician
N. V. Melnikov of Russian Academy of Sciences (ICEMR RAS), Moscow, Russia
T. N. Matveeva, Dr. Eng., Deputy Director for Research, Head of the Dept. of Complex Extraction of Mineral Components from Natural and Technogenic Raw Materials, e-mail: tmatveyeva@mail.ru

The results of experimental studies of a bentonite-polymer composites (BPC) in the process of pelletizing high-quality iron ore concentrate are presented. Alkali-activated bentonite clay from the “10^th Khutor” deposit (Republic of Khakassia) was used as the main ingredient of BPC. The polymer additive is xanthan gum. Xanthan gum, being a high-molecular compound, is capable of forming higher spatial structures (three-dimensional) and is characterized by a high thickening ability, and its solutions have pronounced pseudoplastic properties at low polymer concentrations. The bentonite-polymer composite considered in this work is a mixture of an organic polymer and bentonite clay, which has enhanced binding and strengthening ability. The experimentally obtained data were compared with the characteristics of pellets, produced in the laboratory, using the same method from the blend from current pelletizing plant. The pellets were fired in a laboratory high-temperature furnace VSP-220-1350 designed by NPVP “TOREX”. The maximum temperature in the oven is 1300 °C. The hardware design of the furnace makes it possible to successfully carry out laboratory roasting under conditions as close as possible to the conditions of the process of thermal strengthening of pellets in existing roasting machines. In addition to the strength properties of raw and roasted pellets, the difference in the degree of clumping (yield of the control class) and porosity of the completed pellets was recorded. It has been established that replacing a pure bentonite binder with a bentonite-polymer composite with xanthan gum can significantly increase the strength of the pellets withal increasing the porosity and degree of clumping, which indicates the fundamental possibility of reducing binder consumption while maintaining the quality characteristics of the pellets. Increasing the yield of product of the control size class and the strength properties of pellets will increase the productivity of the site, as well as reduce the circulation load on the pelletizer.
The authors express their gratitude to the staff of the laboratory of pelletizing of Bentonite of Khakassia Ltd. and NPVP «Torex”for their assistance in conducting research.

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