Effect of viscosity of tar and body ageing on properties of unfired tarred magnesite refractories

Conclusions With the use of tars with low viscosity and with a content of 70% pitch, it is possible to obtain from cooled bodies, pressed unfired magnesia articles with increased strength and density. With the use of tars with high viscosity, the production of dense articles is possible by pressing them from hot bodies.Prolonged ageing of magnesia bodies containing low-viscous tar in the heated state improves the physicomechanical properties of unfired articles. For bodies containing viscous tar, prolonged ageing in the hot state does not give effective results.Translated from Ogneupory, No. 7, pp. 54–57, July, 1966.     

Light-weight foam kaolin products of an apparent density of 0.5–0.7 g/cm3

Conclusions The technological parameters were developed for producing light-weight foam refractories of an apparent density of 0.5–0.7 g/cm³ from secondary kaolins. The principal requirements are the use of fineground grog and the addition of soluble methyl cellulose to the body.The pores of foam kaolin refractories are fine, the structure homogeneous, and the gas permeability lower and the physico-thermal properties better than for foam grog refractories.Translated from Ogneupory, No. 8, pp. 44–48, August, 1973.