INFRARED STUDY OF KAOLIN RAW MATERIALS OF BELARUSIAN DEPOSITS

Abstract

The paper presents the results of infrared study of primary kaolins of Belarusian deposits Sitnitsa and Dedovka in natural state and enriched with hydraulic sieve method. It is known that the territory of the Republic of Belarus locates the most extensive and thoroughly explored deposits, such as Sitnitsa – with total reserves of primary kaolin about 2.53 million tons (the eastern part is within the projected building stone open-pit mine Sitnitskoe) and Dedovka – with total reserves of primary kaolin 7.02 million tons and secondary kaolin 1.23 million tons. The paper determines the structure features of kaolins Sitnitsa and Dedovka, in which kaolinite is represented in the form of large intergrowths consisting of superimposed distorted lamellar particles of various thickness and close to a hexagonal shape. The calculated structural formulas of the kaolinite mineral of primary kaolin indicate that Mg2+, Fe3+ and Ti4+ cations are present in the tetrahedral and octahedral layer of kaolinite. The infrared study has allowed to determine the natural kaolins' structural features, such as their crystal structural imperfections with the presence of dickite mineral in primary kaolins. The paper determines the values of the crystallinity index (according to Hinckley) for natural and enriched kaolin Sitnitsa (0.94 and 1.11) and Dedovka (0.98 and 1.04). Analysis of the infrared spectra of natural kaolins in the high-frequency region has allowed to determine the presence of OH groups in the interlayer space, inside and on the surface of the octahedral layer, as well as adsorbed water molecules, which have a significant impact on the technological properties of the kaolin raw materials.