REC «Mekhanobr-Tekhnika» (St. Petersburg, Russia):

Arsentyev V. A., Research and Development Director, Doctor of Engineering Sciences, ava@npk-mt.spb.ru
Gerasimov A. M., Researcher, Candidate of Engineering Sciences, gerasimov_am@npk-mt.spb.ru
Mezenin A. O., Chief Specialist, Candidate of Engineering Sciences, mezenin_ao@npk-mt.spb.ru

The paper presents the results of the Troshkovskoye deposit kaoline ore dressability study with application of hydrothermal modification for the purpose of kaoline concentrate subsequent chemicaland-metallurgical processing with a view to alumina production. It is shown, that provision of a high-performance kaolines processing technology requires modification of starting kaoline feed structure, thus providing for mineral product with particles that are characterized by a lower ability, if compared with starting kaoline feed, for interacting with each other and with dispersion medium. An approximate comparative technical and economical evaluation of two technologies has been accomplished: the conventional wet gravity technology, developed at the «Mekhanobr» Institute, and the proposed technology that includes kaoline feed processing in autoclave with subsequent wet sizing. As a result of the study, it was established, that high-silica kaoline ores are a promising raw material for alumina production. Kaoline feed hydrothermal modification in autoclave leads to a considerable decrease in kaoline slurry viscosity and facilitates subsequent efficient beneficiation. The developed process flow diagram of high-silica kaoline raw material wet processing permits to produce kaoline concentrate with Al₂O₃ mass fraction of 30.1 %, recovery being 91.1 %, suitable for chemical-and-metallurgical conversion to alumina.
The work was performed with the aid of the Russian Science Foundation Grant (Project No. 15-17-30015).

1. Rakhimov R. Kh., Rashidov Kh. K., Yermakov V. P., Rashidov J. Kh., Allabergenov R. J. Resource saving and energy efficient technology of the production alumina from secondary kaolin with Angren deposit. Computational Nanotechnology. 2016. No. 1. pp. 45–51.
2. Galyamov V. Sh. Development of high-performance technology of low-grade kaolin of Eleninskoye deposit beneficiation. Dissertation for the degree of Candidate of Engineering Sciences. Magnitogorsk, 2014. 122 p.
3. Bergaya F., Lagaly G. Handbook of clay science. 2^nd ed. Amsterdam: Elsevier, 2013. 274 p.
4. Colyk V., Huber S., Farghaly M. G., Prolss G., Endres E., Neesse T., Hararah M. A. Higher kaolin recovery with a water-injection cyclone. Mineral Engineering. 2011. Vol. 24, No. 2. pp. 96–108.
5. Salahudeen N., Nasiru A., Ahmed A. S., Dauda M., Waziri S. M., Okonkwo P. C., Isa M. T. Chemical and physical comparative study of the effect of wet and dry beneficiation of Kankara kaolin. Nigerian J. of Technology. 2015. Vol. 34, No. 2. pp. 297–300.
6. Choudhary R. P., Sheoran A. S., Trivedi S. K. A small kaolin beneficiation unit: State of art. Int. J. Earth Sci. and Engineering. 2012. No. 4. pp. 775–781.
7. Buyanov Yu. D., Serdyuk B. P. The problems of lowgrade clay minerals beneficiation in the manufacture of complete construction ceramics. Stroitel’nye Materialy. 2003. No. 2. pp. 34–36.
8. Serdyuk B. P., Efremov I. I. Prospects of Kudinovskoe field enriched clays application in the production of fine construction ceramics. Stroitel’nye Materialy. 2003. No. 2. pp. 37–38.
9. Gorbachev B. F., Krasnikova E. V. State and possible ways of development of raw material base of kaolins, refractory and high-melting clays in the Russian Federation. Stroitel’nye Materialy. 2015. No. 4. pp. 6–17.
10. Povarov A. I., Malova N. N., Khazanova I. V., Bannikov I. G. Beneficiation of secondary kaolin of Angren deposit. Alumina production. Collected works of VAMI. 1969. No. 65–66. pp. 183–186.
11. Sysa O. K. Hydrothermal modification of structure and properties of clay raw materials. Dissertation for the
degree of Candidate of Engineering Sciences. Belgorod, 2008. 158 p.
12. Evtushenko E. I., Sysa O. K. Structural modification of the raw clay under hydrothermal conditions. Izvestiya Vuzov. Severo-Kavkazskiy Region. Tekhnicheskiye Nauki. 2006. No. 2. pp. 82–86.