Cement-Free Refractory Concretes. Part 9. HCBS and Ceramic Concretes in the System Al2O3-SiO2-SiC1

The priority-chronological aspect of research and technological development in the field of SiC-containing HCBS and ceramic concretes in the systems Al2O3-SiO2-SiC and Al2O3-SiO2-SiC-C is described. Results of studying the effect of firing temperature and prolonged (up to 100 h) high-temperature heat treatment on SiC oxidation kinetics of different dispersion and content are considered. Marked oxidation, accompanied by specimen weight increase and growth, is noted after 1200 degrees C and is significant at 1300 - 1400 degrees C. The effect of the firing temperature in the range of 1000 - 1400 degrees C and prolonged exposure in a tunnel furnace (60 h at 1300 - 1400 degrees C) on the dynamics of phase transformations and structure of specimens of the matrix system based on composite composition HCBS (bauxite + 11% VFQG), as well as with an additional content of 15% SiC is studied. In contrast to firing in air, during service of monolithic chute mixes in the Al2O3-SiO2-SiC-C system, concrete working surface is largely insulated from air due to cast iron and slag. This sharply reduces the rates of both SiC oxidation and carbon burn-off. Lining zonal structure is specified. Data for the effect of heating and cooling on ceramic concrete elasticity modulus are provided.