EXAMINATION OF CONDITIONS FOR OBTAINING AMORPHOUS SILICA FUME FROM NATURAL DIATOMITE

Selyaev Vladimir Pavlovich, RAACS academician, doctor engineering sciences, professor, head of sub-department of building structures, Ogarev Mordovia State University (68 Bolshevistskaya street, Saransk, Russia), ntorm80@mail.ru
Sedova Anna Alekseevna, Candidate of chemical sciences, associate professor, sub-department of analytical chemistry, Ogarev Mordovia State University (68 Bolshevistskaya street, Saransk, Russia), iman081@gmail.com
Kupriyashkina Lyudmila Ivanovna, Candidate of engineering sciences, professor, sub-department of building structures, Ogarev Mordovia State University (68 Bolshevistskaya street, Saransk, Russia), kupriashkina.liudmila@yandex.ru
Osipov Anatoly Konstantinovich, Candidate of chemical sciences, associate professor, head of sub-department of analytical chemistry, Ogarev Mordovia State University (68 Bolshevistskaya street, Saransk, Russia), ntorm80@mail.ru

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Background. Synthesis of nanodispersed powders of amorphous silica is an important task, as they have a high reaction activity. The materials, obtained from these powders, have high physico-mechanical, thermal properties, corrosion resistance. The aim of this work is to study the optimal conditions for obtaining fine powder of amorphous silica with low costs of energy.
Materials and methods. Amorphous silica was obtained from natural diatomite through processing by an aqueous solution of alkali at different temperatures, time of incubation and the ratio of G-T phases.
Results. It has been established that the yield of silica depends on the alkali concentration, temperature and time of incubation. The authors have developed a method of purification of the synthesized silica and determined the elemental composition and size distribution of silica, depending on the alkali concentration, temperature and time of incubation, the ratio of liquid and solid phases.
Conclusions. The optimal conditions for obtaining amorphous fine silica fromnatural diatomite are a 20 % solution of NaOH, thermostating at 90 °C, incubation time of 3 hours, the ratio l : s = 12 : 1. The method of producing silica is characterized by simplicity of hardware design, low cost of raw materials, low cost of electricity.

amorphous silica fume, natural diatomite, alkali solution.

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