Study of compaction of high-alumina ceramoconcretes. 4. The effect of firing temperature on the properties of a matrix system and on ceramoconcrete

The effect of firing temperature on variations of the linear sizes, open porosity, apparent density, and mechanical strength both of the matrix system and of industrially produced ceramoconcretes based on a high-concentrated ceramic binding suspension (HCBS) containing 90% bauxite and 10% quartz glass is investigated. Experimental materials based on HCBS of density 2.62–2.77 g/cm³ (C _V = 0.65–0.70) with the content of particles of size below 1 μm varying from 4 to 15% encompass the whole spectrum of quantitative parameters of initial suspensions that are prescribed or possible in industrial production. Samples based on a bauxite HCBS with 10% highly disperse quartz glass, as well as samples of ceramoconcrete consisting of the same HCBS (35%) and a bauxite-based refractory filler, were obtained by compaction, heat-treated and fired in the interval of 100–1420°C. Perceptible sintering accompanied by shrinkage and significant strengthening of the material is registered in the interval of 1000–1250°C. A certain expansion and loosening of the material is observed in the range of 1300–1400°C due to intense mullite formation. Significant sintering and strengthening is achieved by protracted firing at 1400–1420°C. Comparative analysis of the properties of the matrix system and ceramoconcrete has established that, other terms being equal, σ_comp of ceramoconcrete amounts to 40–50% σ_comp of the matrix system. __________ Translated from Novye Ogneupory, No. 10, pp. 29–37, October, 2006.