Technogenic Raw Materials in High-Alumina Chamotte Production

Abstract

Abstract The paper presents studies on the production of a high-alumina aggregate with an Al2O3 content of 75% based on fine-grained corundum dust generated by grinding fused corundum. Finely dispersed corundum powder is a by-product and due to the low Al2O3 content (93 – 95%) is not used in further production. It is proposed to obtain high-alumina aggregate without joint grinding of the components. Aggregate was obtained by pressing through a “false grain” from a mixture of kaolin and corundum dust in a certain ratio. The samples firing was carried out at a temperature of 1700°C. The phase composition of the obtained aggregate is represented by 46 – 51% corundum, 45 – 49% mullite. The water absorption of such chamotte is 14 – 16%, open porosity is 33 – 35%, apparent density is 2230 – 2290 kg·m−3. Now, it was not possible to obtain a high-density filler grade ZML and ZMK that meets the requirements of GOST 23037 – 78. The production flow chart of high-alumina chamotte based on kaolin and corundum dust should include a joint fine grinding of the components, or a separate grinding of corundum dust until it passes completely through the 0.063 mm mesh.