Chemical and Metallurgical Institute named after Zh. Abishev (Republic of Kazakhstan):

Oskembekov I. M., Senior Researcher, ilyasosk@yandex.kz

Katkeeva G. L., Ph. D. in Engineering Sciences, Associate Professor, Leading Researcher, katkeeva@mail.ru

The results of the studies, performed with a view to develop a technology for heat-and-power facilities’ bottom ash waste treatment, are presented. The experiments on ash sintering with ammonium bifluoride and ammonium sulphate were performed on the basis of probabilisticand-deterministic approach in order to achieve coal ash breakdown. A mathematical model of sintering was obtained, by means of which the process optimal conditions were determined. Possible production of high-grade silicon oxide from coal ash is described. The effects of sintering factors: temperature, time and liberating reagents consumption were studied. Analysis of partial dependences showed, that in matrix experiments silica recovery degree is mostly affected by sintering process duration and ammonium bifluoride consumption. So, silica recovery is increased by 27 % on the average with sintering duration increase from 30 to 180 min, and ammonium bifluoride consumption – from 50 to 150 %. As a result, a silica product – silicon oxide is produced, its chemical composition complying with the requirements for high-grade silica white. The proposed treatment technology will permit not only to enhance the raw material base for silica production, but also significantly improve the environmental situation in the region.

1. Pat. 2363742 Russian Federation.
2. Kraydenko R. I. Ftoroammoniynoye razdeleniye mnogokomponentnykh silikatnykh system na individualnyye oksidy. Avtoreferat dissertatsii… kandidata khimicheskikh nauk (Multicomponent silicate systems fluorine ammonium separation into individual oxides. Author’s abstract of Ph. D. dissertation). Tomsk, 2008, 21 p.
3. Andreev A. A., D’yachenko A. N. Fluoride technology — the future of the chemical industry. Chemistry & Business, 2009, No. 5, p. 10.
4. Innovation pat. 27032 Republic of Kazakstan.
5. Malyshev V. P. Veroyatnostno-determinirovannoye planirovaniye eksperimenta (Probabilistic and deterministic planning of experiment). Alma-Ata, Nauka, 1981, 116 p.
6. Malyshev V. P. Matematicheskoye planirovaniye metallurgicheskogo i khimicheskogo eksperimenta (Mathematical planning of metallurgical and chemical experiment). Alma-Ata, Nauka, 1977, 37 p.
7. GOST 18307—78. Sazha belaya. Tekhnicheskiye usloviya (Carbon white. Technical conditions). Moscow, GosStandart of Russia, Standards publishing house, 1998, 18 p.