The Properties of Fire Clay Brick

Fire clay brick belongs to a weak acid refractory product, can resist acid slag and acid gas erosion, resistance to alkaline substances slightly worse. Fire clay brick has good thermal performance, resistance to rapid cooling hot.  The refractoriness of fire clay brick reaches up to 1690-1730 ℃, but the load softening temperature is more than 200 ℃ lower than silica brick.

With the temperature rising, the volume of the clay brick is uniformly expanded in the temperature range of 0-1000 ℃, the linear expansion curve is similar to a straight line, linear expansion rate is 0.6% -0.7%, only about half of the silica brick. When the temperature reaches 1200 ℃ and then continue to heat up, the volume will start to shrink from the maximum expansion. The residual shrinkage of fire clay brick leads to the cracking of the masonry gray seam, which is a major drawback of fire clay brick. When the temperature exceeds 1200 ℃, the low melting point material gradually melted in fire clay brick, because the particles by the surface tension and rely on each other very tight, resulting in volume shrinkage.






Fire clay brick is clay product with Al203 content of 30% to 40% of aluminum silicate material. 50% of the soft clay and 50% hard clay clinker, according to a certain size requirements of the ingredients, after molding, drying,  under the high temperature 1300-1400 ℃ burning clay brick. The mineral composition of fire clay brick is mainly kaolinite and 6%一7% impurities (potassium, sodium, calcium, iron, iron oxide). The firing process of fire clay brick, is mainly kaolinite decomposition of water to produce mullite crystallization process. In the firing g process, the Si02 and Al203 in the clay brick form a eutectic and low melting point silicate with the impurity, surrounded by the mullite crystals.