Wall materials based on low-grade loams and industrial waste

Clay raw materials used in Kyrgyzstan for the ceramic industry characterized as low-plasticity , highly sensitive and saline. In addition, the high content of carbonates in loams leads to the production of low-quality bricks. In order to obtain ceramic bricks with high-quality performance characteristics, it is necessary to use innovative approaches in the preparation of clay raw materials. The raw used materials were local loess-like loams from the Orok deposit and ash from the Bishkek thermal power plant and a surfactant – sodium naphthenate. The loam and ash subjected to mechanochemical activation by joint grinding in activator-mixer and adding sodium naphthenate together with mixing water. The dried cylindrical samples fired in the temperature range of 900, 950 and 1000 0 C. The results of the studies showed that mechanochemical activation of ash-clay raw materials increases the plasticity of the clay-ash mass by 140 %, while reducing the molding moisture and sensitivity coefficient. The sintering process is intensified: at a firing temperature of 950 0C and 60 % ash, it is possible to obtain a shard with a density of 1.57 g/cm3 and water absorption of 17 %. The compressive strength is 16.3 MPa. Amorphization and destruction of raw material particles contribute to an increase in the glass phase content. As a result, open pores are tightened, forming a strong monolithic structure. The obtained samples based on mechanochemical activation with the addition of 60 % ash have the M150 grade and frost resistance of F 25.

loams, ceramic mixture, mechanical-chemical activation, brick, compressive strength, water absorption, fire shrinkage, microstructure, firing temperature