Pologivskiy Kaolin Deposit: Geology, Mineral and Chemical Composition, Technological Properties

Abstract

The area of the Pologivskiy deposit of kaolins and refractory clays is located on the border of two geological regions: the Azov crystalline massif and the Konksko-Yalynska depression. Precambrian crystalline rocks and sediments of the Cretaceous, Paleogene, Neogene, and Quaternary systems take part in the geological structure of the district. The geological structure of the district is based on the results of field exploration (23–25) and geological surveying works. Deposits of the Quaternary system are widespread in the territory and are similar to mantle on the underlying rocks. The lower border of the Quaternary system is formed at the base of the Berezanskiy climatolite in accordance with the Geological Map of Ukraine legend (the scale 1:200 000) of the 1996 Central Ukrainian series. The underlying rocks are red-brown Pliocene clays in most parts of the territory, in the rest there are rocks of crystalline basement of Cretaceous, Paleogene and Neogene systems. The thickness of the Quaternary deposits is 10–20 m. Deposits of the Novopetrivska Neogene suite are productive for the extraction of clays and kaolins, in the base of which the undivided deposits of the Upper Eocene (Kyivska suite) and Oligocene (Kharkivska suite) lie. These are coastal-marine deposits – marls, calcareous clays, siltstones, weakly cemented sandstones and glauconite quartz sands. The total thickness of the Kyivska and Kharkivska suites varies from 0,0 to 60–70 m. Clays and kaolins are characterized by almost the same mineral composition. Most of them are composed of fine-grained kaolinite, and quartz predominates among impurities. Accessory and ore minerals are represented by zircon, rutile, ilmenite and hematite. Quartz is present in clays and kaolins in the form of rolled, semirolled and unrolled grains. High-quality aluminosilicate products are obtained from the kaolins of the deposit. Pologivskiy kaolin can be used to make chamotte without the clay addition, as well as a binder. The ratio of chamotte and binder is 80–20 %. The refractories obtained in the laboratory meet the requirements of high density for Class A blast furnace bricks and other products of appropriate determination. Pologivskiy clays are recognized as suitable for the production of 100 % refractories, as well as a binder component instead of ChasovYarska clays. Products made entirely of semi-acid clay meet the requirements for semi-acid refractory products of class B. Pologivskiy kaolins and clays have long been used in refractory, machine-building, ceramic, cement and other industries.