Low cost cold face insulation bricks from common clay

Attempts have been made in this work to develop low cost cold face insulation bricks from common clay, which could be manufactured in the rural sector. Different combustible materials were used for increasing the porosity of the bricks. Firing was done at 900°, 1000°, 1050° and 1100°C. Thermal conductivity values varied between 1.8 and 7.2 gm cal/sec/cm2/°C.cm x 10-4which is similar to that of conventional insulation bricks. Bulk density varied from 0.5S to 0.85 gm.cm-2, while apparent porosity varied between 60 and 78. Cold crushing strength was between 4 and 11 kg.cm-2. Permanent change after reheating for 24 hrs was almost nil. Three compositions satisfied the IS specification 2042 (1972) type 3 of low temperature insulation bricks to be used at a maximum hot face temperature of 850°C. These bricks can be used as back up insulation in industrial ceramic kilns and furnaces. This type of raw mix-insulation can also be used as monolithic in potters� �puans� and other furnaces. © 1984 Taylor & Francis Group, LLC