Kaolin from Poletaevskoye deposit (Chelyabinsk region, Russia) in ceramics production

Abstract

The paper presents the results of a study of the properties of Poletaevsky kaolin with the aim of using it in the ceramic industry. Based on the results of determining the chemical, mineral and granulometric composition. The mineral composition of Poletaevsky kaolin is kaolinite 80–85 wt %, muscovite and illite 10–15 wt %, quartz up to 10–15 wt %. It has been established that the Hinckley index for Poletaevsky kaolin is 0.68, compared to 1.38 for Glukhovetsky one. The ratio of highly ordered kaolinite to low ordered kaolinite for Poletaevsky kaolin is 22 : 78, for Glukhovetsky kaolin the ratio of highly ordered kaolinite to low-ordered kaolinite is 57 : 43. It was established that Poletaevsky kaolin can be used in the production of ceramic materials by plastic or semi-dry molding. The determined low content of high-ordered kaolinite and the insignificant content of particles less than 2 μm according to the results of laser diffraction analysis can lead to the production of an unstable slip. When firing samples of Poletaevsky kaolin, a minimum water absorption of 5.5 % was achieved at a firing temperature of 1450 °C. In this case, the resulting maximum apparent density was 2.17 g/cm3, the maximum mullite content was 38 %, and the maximum compressive strength was 32 MPa.