National Mineral Resources University (University of Mines) (Russia):

Dubovikov О. А., Ph. D. in Engineering Sciences, Associate Professor
Brichkin V. N., Doctor of Engineering Sciences, Professor, kafmetall@mail.ru
Nikolayeva N. V., Ph. D. in Engineering Sciences, Associate Professor, opiopi@bk.ru

Romashev А. О., Ph. D. in Engineering Sciences, Assistant

With respect to high-silica bauxites, a large number of research works have been performed in recent years, aimed at, first, developmental study of bauxites processing methods, second, improvement of the combined sequential Bayer-roasting method, third, development of a new hydrometallurgical technique for bauxites processing. Study of mechanical beneficiation of bauxites so far did not bring positive results, and, development of a new hydrometallurgical high-alkaline autoclaving processing technique met with considerable equipment-design problems that are still unsolved. The article presents the results of the Middle Timan high-silica bauxites processing into alumina by Bayer’s method with preliminary thermo-chemical conditioning. Bauxites roasting in a wide temperature range with subsequent treatment with alkali liquor permitted to determine the optimum conditions of roasting. From bauxites with silica modulus of 2.27 and 5.06, concentrates were produced with modulus of 8 and 15, respectively. The results of laboratory experiments were corroborated in pilot-scale testing.

1. Dubovikov O. A., Sizyakov V. M. Effektivnyye tekhnologii pererabotki nizkokachestvennykh boksitov (Effective technologies for processing of low-grade bauxites). St. Petersburg, National Mineral Resources University, 2012, 195 p.
2. Certificate of Authorship 479731 USSR.
3. Pat. 2462417 Russian Federation.
4. Pashkevich L. A., Bronevoy V. A., Kraus I. P. Termografiya produktov glinozemnogo proizvodstva. Spravochnik (Thermography of alumina manufacturing products. Reference book). Moscow, Metallurgiya, 1983, 128 p.