Classification Of Fire Clay Bricks

Fire clay brick is widely used in indutrial furnaces and other thermal equipment due to its rich source of raw materials, simple manufacturing process and low cost. It is a type of weak acid refractoy product and one of the most widely used refractory products. 

According to its properties, fire clay bricks can be divided into 4 types: common fire clay brick, clinker fire clay brick, non clinker fire clay brick and high-silica fire clay brick. 

1) Common fire clay brick refers to the fire clay brick containing 36%-42% Al2O3. It has a high yield and wide use. It is made of clay with high plasticity and strong dispersion and clinker. Based on the refractoriness, it can be classified into four grades: Special grade (higher than 1750 ℃), first grade (1730-1750 ℃), second grade (1670-1730 ℃) and thrid grade (1580- 1670 ℃).

2) Clinker fire clay brick contains more than 80% clinker and less than 20% bonding clay. Since its raw materials are lean, it is not easy to deform during the manufacturing process and can maitain its size and shape. The finished products have ideal bulk density, mechanical strength, thermal malleability resistance and high refractoriness.

3) Complete raw material fire clay brick is also called non clinker fire clay brick. It is made of hard clay or pyrophyllite with low plasticity, weak dispersion and small contraction. Since the raw material contains low content of inherent bonding moisture, it can maitain its original particle structure, so additional clinker is not required to be added. 

4) High-silica fire clay brick is made of lean clay and natural quartz sand. According to the type of raw materials, high-silica brick can be divided into two kinds: quartz-kaolinite high-silica brick and quartz-clay high-silica brick. The former contains 75%-80% SiO2 and has a refractoriness of 1710℃ and porosity of more than 25%; the latter has a low refractoriness between 1610℃-1700℃.