TURK 2025

The main ingredient in the production of these products is refractory clay, typically combined with a chamotte component.
Local clay deposits, such as those from Kok-Moynok, and quartz-kaolin sandstones from the Kok-Moynok region have been investigated. To produce chamotte ceramic products using refractory clay from the Kara-Kiche, Kok-Moynok, Tash-Kumyr, and Abshir deposits, natural Kok-Moynok clay has been tested as a substitute for chamotte. Quartz-kaolin from Kok-Moynok sandstone and fired clay from Tash-Kumyr and Abshir (calcined at 800–950°C) have been used in the production of semi-acid refractories.
A comparison of the mechanical properties of these compositions with the bending strength values for fireclay ceramics, as defined by GOST 390-83, has shown that ceramics based on local raw materials are not inferior to the standard in terms of bending strength. The porosity of the samples also meets regulatory standards.
Heat resistance measurements showed that the best-performing composition achieved a thermal stability of 1000°C, comparable to the standard chamotte ceramic (1050°C). Other samples demonstrated lower heat resistance, with a strength loss coefficient of 60–65% at 1000°C. This reduction can be attributed to the dual role of pores in ceramic materials: while they reduce the overall strength of the product, they also inhibit crack propagation, reducing internal stresses and improving thermal resistance. Experimental results indicate that porosity is the primary factor influencing thermal stability in the studied compositions.
The tested ceramic compositions demonstrated fire resistance ranging from 1580°C to 1600°C, corresponding to the SHUS and PV categories of fireclay products. These materials are recommended for use at temperatures up to 1250°C, at which they maintain their thermal resistance without additional shrinkage.