St. Petersburg Mining University (St. Petersburg, Russia):

Sizyakov V. M., Professor, Doctor of Engineering Sciences
Utkov V. A., Professor, Doctor of Engineering Sciences
Brichkin V. N., Head of Chair, Doctor of Engineering Sciences
Gumenyuk A. M., Postgraduate Student
E-mail (common): kafmetall@mail.ru

One of the promising directions in development of the modern technology of alumina production by sintering method is based on using alkali-free feed additives. It permits to solve a number of production tasks, including formation of designed phase composition of products, man-caused materials recycling, resource-supporting, process intensification and target component content increase in limestonenepheline mix. The solution of the last task permits to extend the limited prospects for nepheline ores beneficiation, caused by low grades of valuable components present in nepheline, and by similarity of its properties with those of associated aluminosilicates from feldspar group. Using the feed additives, as low-grade bauxites, waterpurification sediments, ferroalloy smelting and foundry production slag, provide for significant aluminium oxide grade increase in sinter, improvement of consumption parameters per unit of finished product and growth in production of final product. With that, high-level recovery of valuable components, as well as other high production process indices are maintained. The experiments proved that using low-grade bauxites additives in the amount of 5 to 30 % with respect to ore component provides for production growth from 4.5 to 27.9 %, if compared with the base case. It is shown that feed additives with high dispersion ability create conditions for earlier development of sintering processes, thus providing for their intensification even with relatively small contents in limestone-nepheline mix composition. As can be seen from the above, application of alkalifree feed additives is a promising trend in scientific and technological research with a view to solve alumina production tasks, as well as related processing problems.
The work was performed with the financial aid from the Ministry of Education and Science of the Russian Federation (government order, project No. 14.577.21.0208, dated 02 November 2015. UIPNI RFMEFI57715X0208).

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