Nosov Magnitogorsk State Technical University, Magnitogorsk, Russia:

I. A. Grishin, Head of a Chair, Associate Professor, Candidate of Engineering Sciences, igorgri@mail.ru
K. V. Burmistrov, Associate Professor, Candidate of Engineering Sciences

Geotechnology Scientific and Technological Center, Chelyabinsk, Russia:
A. V. Sokolovsky, Chief Executive Officer, Doctor of Engineering Sciences

Refractories are highly important products for the metallurgy, ceramics manufacture, paint-and-varnish industry, paper making etc. At present all companies engaged in mining and processing of kaolin clays have accumulated huge piles of substandard products on the ground surface. Quality of clays in subsoil is also unstable. Such raw material is only applicable for manufacturing standard quality products after preliminary processing. This article addresses the specified problem. In terms of Kumak deposit, the authors consider the technology of clay quality improvement through reduction of iron content of the initial raw material in order to obtain the wanted quality feedstock for the production of refractories. The article discusses iron occurrence forms in kaolin clays and shows mass fraction of oxides which influence the quality of the raw material. The distribution of oxides of aluminium, silicium and ferrum per size grades is illustrated. In the test sample of kaolin clay, the aluminium oxide content of coarse particles is increased while ferrum oxides are distributed uniformly. Based on the size grade distribution of components, pretreatment by sizing in aqueous medium and by magnetic separation is suggested. The article reports experimental results on sizing of Kumak deposit clay on a laboratory cyclone and subsequent magnetic separation of the cyclone product in varied-strength magnetic field. It is shown that the production of high-quality material requires the magnetic field strength of 1200 kA/m, the regular quality refractory products need the magnetic field with a strength up to 120 kA/m. The eff ect of consumption of various flocculants on settling velocity of final product for the manufacture of refractories is also discussed. The tests included flocculants BASF’s series Magnafloc^® developed specifically for the mining industry: Magnafloc^® 10; 1011; 333; 336; 430; 156; 5250. It is decided that Magnafloc^® 333 is the best variant as it results in the least turbidness of discharge and in the highest density of the thickened product. Developed in the course of the research implementation, the clay processing technology includes sizing, magnetic separation and dewatering of kaolin product; in addition, it is proved to be efficient to use non-ionic high-molecular flocculants with the molecular mass higher than 200 atomic mass units.

1. Deposits of USSR kaolins. Ed.: B. F. Gorbachev. Moscow : Nedra, 1974. 248 p.
2. 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. Stroitelnye materialy. 2015. No. 4. pp. 6–17.
3. Solodkiy N. F., Solodkaya M. N., Shamrikov A. S. Raw materials base of ceramic and fire-proof industry in the Urals. Modern state and prospects of use of raw materials base in Chelyabinsk Oblast : collection of scientific articles. Chelyabinsk, 2000. pp. 106–107.
4. Afonina G. A., Leonov V. G. Research of chemical and mineralogical composition and ability sintering of clay from Shulepovo deposit. Izvestiya Tulskogo gosudarstvennogo universiteta. Estestvennye nauki. 2014. No. 1-2. pp. 89–98.
5. Khatkov V. Yu., Boyarko G. Yu. Problem of replacement of import flows of kaolin. Uspekhi sovremennogo estestvoznaniya. 2004. No. 8. pp. 139–142.
6. Slepova I. E., Tarasov R. V., Makarova L. V. The evaluation of opportunity of the use clay of Penza region deposites for production the ceramic products. Sovremennye nauchnye issledovaniya i innovatsii. 2014. No. 8. Available at: http://web.snauka.ru/issues/2014/08/37211 (accessed: 15.05.2017).
7. Nowak A., Makary B. The enrichment of the ceramic clays from the wastes of the Zebrzydowa Meve. 15^th Mining Congress of Turkey. Turkey, 1997. pp. 331–336. Available at: http://www.maden.org.tr/resimler/ekler/4da4aea8e38ac93_ek.pdf (accessed: 15.05.2017).
8. Rimkevich V. S., Eranskaya T. Yu., Leontev M. A., Girenko I. V. Development of fluoride hydrochemical method of kaolin concentrates enrichment. Fundamentalnye issledovaniya. 2014. No. 9. pp. 2023–2027.
9. Platova R. A., Maslennikova G. N., Platov Yu. T. Biochemical method of removing iron from Zhuravlinyi Log kaolin. Steklo i keramika. 2013. No. 2. pp. 15–22.
10. Ortiz J., Montaño M., Plascencia A., Salinas J., Torrentera N. et al. Influence of Kaolinite Clay Supplementation on Growth Performance and Digestive Function in Finishing Calf-fed Holstein Steers. Asian-Australasian Journal of Animal Sciences. 2016. Vol. 29, No. 11. pp. 1569–1575.
11. Kogel J. E. Mining and Processing Kaolin. Elements. 2014. Vol. 10, Iss. 3. pp. 189–193.
12. Ryan J. N., Gschwend P. M. Extraction of iron oxides from sediments using reductive dissolution by titanium (III). Clays and Clay Minerals. 1991. Vol. 39, No. 5. pp. 509–518.
13. Calderón G. D. T., Rodríguez J. I., Ortiz-Méndez U., Torres-Martínez L. M. Iron Leaching of a Mexican Clay of Industrial Interest by Oxalic Acid. The AZo Journal of Materials Online. 2005. Vol. 1. Available at: https://www.azom.com/article.aspx?ArticleID=3133 (accessed: 15.07.2017).
14. Maurya Ch. B., Dixit Sh. G. High gradient magnetic separation of china clays. Bulletin of Materials Science. 1988. Vol. 10, Iss. 5. pp. 471–475.
15. Cengiz I., Sabah E., Ozgen S., Akyildiz H. Flocculation of Fine Particles in Ceramic Wastewater Using New Types of Polymeric Flocculants. Journal of Applied Polymer Science. 2009. Vol. 112, Iss. 3. pp. 1258–1264.
16. Kim M., Kim S., Kim J., Kang S., Lee S. Factors affecting flocculation performance of synthetic polymer for turbidity control. Journal of Agricultural Chemistry and Environment. 2013. Vol. 2, No. 1. pp. 16–21.
17. Dao V. H., Cameron N. R., Saito K. Synthesis, properties and performance of organic polymers employed in flocculation applications. Polymer Chemistry. 2016. No. 7, Iss. 1. pp. 11–25.