Insulating firebrick compsn. - contg. aluminous fireclay, calcium carbonate, hydraulic binder, polystyrene balls and additives

摘要

Compsn. for mfr. dry slip casting of insulating bricks consist of a mixt. of 67-75% aluminous fireclay contg. 42-44% alumina of surface area 6000 contg; 19-29% CaCO3 of surface area 6500 cm2/g; 3% of a hydraulic binder, 1% fibrous materials and less than 1% sec. additives which adjust the rheology of the slip. The mixt. also contains a porophore to lower the density and water in an amt. 20-25 wt.% wrt. the solids. The porophore is pref. expanded polystyrene in the form of balls 1-2mm. dia. used in an amt. of 140 ml/100 g of mixt. Closer control of the porosity and pore size of the insulating bricks can be achieved.