The relationship between porosity, firing temperature, and corrosion resistance of slip-cast sillimanite

GT V02 1961 159-166

A number of sillimanite blocks were produced varying in apparent porosity from 1240% when jived at temperatures from 1450 to 1600°C. The porosity was produced artificially by adding naphthalene to the slip. The corrosion resistance of the samples was estimated by immersing them in molten glass at 1400" C nntl measuring the attack at the flux line. A definite relationship between apparent porosity and the corrosion by molten glass was established which could be expressed as: corrosion index = 0.92 (apparent porosity) + 12.88 The effect of firing temperature on this relationship was found to be negligible over the range considered. This implies that enhanced corrosion resistance would be obtained much more economically if it were possible to reduce the porosity by means other than increasing the $ring temperature, providing this did not debase the block.

T. S. Busby & J. Eccles
The British Glass Industry Research Association, Sheffield