This paper deals with the addition of bagasse with 1% polystyrene (P.S.) as an organic matter to kaolin and grog in a kneader mixer to produce insulating fire-bricks (IFB) with adequate physical and thermal properties.
Clay and grog were mixed in a kneader mixer on a plant scale for twenty minutes to give a paste of ~ 18-20%
moisture content. The paste was hand moulded into shapes and dried. The shapes were then fired according to a certain schedule so as to avoid the rapid evolution of gases which causes cracks and destruction of the bricks.
Physical properties such as water absorption, apparent porosity and bulk density were performed according to
ASTM. The mechanical properties of these bricks were also determined. Also, the author was able to construct a simple apparatus to measure the thermal conductivity by the comparative method.
It was found that 3 % of bagasse with addition of 1% P.S. is accompanied by an increase in the water absorption and apparent porosity of the fired bricks. It also causes a decrease in cold crushing strength as well as thermal conductivity.
Mathematical relations were developed to relate thermal conductivity to apparent porosity, and thermal conductivity to temperature.
Finally, an economic study was performed for a product of bulk density 1.06 g/cm3 which showed that the use of 3% of bagasse with 1% P.S. gives the maximum saving.