Effect investigation of a thinning additive on the physical and mechanical properties of celsian ceramics obtained by slip casting

The article discusses the physical and mechanical regularities of ceramics formation based on the BaO—Al2O3—SiO2 system by slip casting into gypsum molds, and also investigates the rheological properties of a slip based on сelsian and the physicochemical properties of products made from it. The samples were made according to the following technology: the first stage is synthesis of celsian in a muffle furnace at a temperature of 1200 °C with a maximum temperature holding for 2 hours. The synthesis products were ground in a planetary mill to a residue on the № 0063 sieve of no more than 0.2 %. Then, slips with different moisture content without additives and with the addition of 0.10, 0.15 and 0.20 wt. % thinning additive Dolapix PC 67 were made. The second stage is to obtain samples by casting slip into gypsum molds. Firing of products took place in a muffle furnace at a temperature of 1350 °C with a two-hour holding. The optimal amount of thinning additive in the celsian slip was determined, which corresponds to 0.10 wt. %. It was found that, in the studied area of technological parameters, the material acquires the best properties at a sample firing temperature of 1350 °C and is characterized by the following indicators: water absorption — 10.20 %, apparent density — 2.15 g/cm3, open porosity — 21.04 %.