Effect of sulfuric acid concentrations on gel formation during serpentine leaching

This article presents the results of a study of the effect of sulfuric acid concentration on the leaching process of serpentine, with a special focus on the mechanism of polysilicon acid gel formation. A detailed analysis of the kinetic features of the dissolution of serpentinite under various conditions and ratios in mineral acid, in particular, in sulfuric acid, has been carried out and considered. It has been established that the key factor limiting the rate of the process is the formation of colloidal forms of silica on the surface of the particles, which leads to passivation of the reaction zone. Using the methods of IR-Fourier spectroscopy and chemical analysis, it is shown that the transformation of silica from the crystalline structure of serpentinite to an amorphous state begins when the concentration of sulfuric acid reaches 40–50% of the stoichiometrically required amount. It was found that under such conditions, a stable gel layer forms on the surface of the particles, which significantly slows down the further dissolution of magnesium. The data obtained make it possible to determine the optimal parameters of acid treatment of serpentinites, ensuring maximum extraction of target components with minimal gelation. The results of the study are of great practical importance for the development of effective technologies for processing serpentinite raw materials, including the production of magnesium and silica compounds.

Auyeshov A., Eskibayeva Ch., Arynov K., Kolesnikova O., Zhumadildaeva A. Effect of sulfuric acid concentrations on gel formation during serpentine leaching. MIAB. Mining Inf. Anal. Bull. 2025;(12):17-27. DOI: 10.25018/0236_1493_2025_12_0_17.

The article was prepared with the financial support of grant financing of scientific and (or) scientific and technical projects and programs for 2023-2025 by the Committee of the Ministry of Internal Affairs of the Republic of Kazakhstan (grant No. AR19676952).

A. Auyeshov¹, Dr. Sci. (Eng.), Professor, e-mail: centersapa@mail.ru, ORCID ID: 0000-0002-3504-9117,
Ch. Eskibayeva¹, Cand. Sci. (Eng.), Assistant Professor, e-mail: yeskibayeva@internet.ru, ORCID ID: 0000-0002-8049-8851,
K. Arynov, Dr. Sci. (Eng.), Professor, Aspan Tau LTD Limited Liability Company, 160024, Almaty, Kazakhstan, e-mail: tau_aspan@mail.ru, ORCID ID: 0000-0002-1440-8248,
O. Kolesnikova¹, Master of Technical Sciences, Researcher, e-mail: ogkolesnikova@yandex.kz, ORCID ID: 0000-0001-6871-8367,
A. Zhumadildaeva¹, Master of Technical Sciences, e-mail: asel.zhumadildaeva@mail.ru, ORCID ID: 0009-0000-7379-2190,
¹ M. Auezov South Kazakhstan University, 160012, Shymkent, Kazakhstan. 

A. Auyeshov, O. Kolesnikova, e-mail: centersapa@mail.ru; e-mail: kas164@yandex.kz.

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