The main composition of refractory material

The mineral composition of refractory brick is mainly kaolinite (Al2O3 · 2SiO2 · 2H2O) and 6% ~ 7% impurities (potassium, sodium, calcium, titanium, iron oxide). Select the high density, low water absorption of raw materials,  a reasonable level of preparation is the key to make low porosity refractory brick. Refractory brick is made with 50% soft clay and 50% hard clay clinker according to certain granularity requirements. After molding and drying,  firing under high temperature of 1300 ~ 1400 ℃.

The firing process is mainly due to the process of crystallization of mullite (3Al2O3 · 2SiO2). The SiO2 and Al2O3 in the refractory brick form a eutectic and low melting point silicate with the impurity during the firing process, surrounded by mullite crystals. The maximum temperature in the firing process is usually controlled at 1350 ° C to 1380 ° C, and the firing temperature of the low porosity fire clay brick (1420 ° C) is increased. The shrinkage of ceramic fiber board is slightly increased, so that the density of sillimanite brick increases slightly and the low porosity is decline.

Refractory brick do not use the same kind of mud to use different appliances, fire mud selection of cleaning water, accurate weighing modulation, uniform mixing, tune the mud can not be arbitrarily diluted with water, mortar fullness is greater than 95% or more, ensure solid brick joints, the surface brick seam jointing with virgin pulp, the shell can not correct the parts with mud.

Refractory brick has a certain shape and scale of refractory material, large unit volume weight, large density, indicating that the density is good, the strength may be high, also known as high temperature load deformation temperature, called the burner change or called the residual line change.