Several types of refractory bricks

Silica bricks refer to refractory bricks containing over 93% SiO2, which are the main types of acidic refractory bricks. They are primarily used for constructing coke ovens, as well as for the arches and other load-bearing sections of various glass, ceramic, carbon calcining furnaces, and thermal kilns for refractory bricks. They are also used in the high-temperature load-bearing sections of hot blast furnaces, but are not suitable for use in thermal equipment with temperatures below 600℃ and significant temperature fluctuations.

Clay bricks, primarily composed of mullite (25%～50%), glass phase (25%～60%), and feldspar and quartz (up to 30%), are typically made from hard clay. The raw material is pre-fired into clinker, then mixed with soft clay and formed using semi-dry or plastic methods at temperatures ranging from 1300 to 1400°C to produce clay bricks. Unfired products and不定形 materials can also be made by adding a small amount of water glass, cement, and other binders. It is commonly used as refractory bricks in blast furnaces, hot blast stoves, heating furnaces, power boilers, lime kilns, rotary kilns, ceramic kilns, and refractory brick firing kilns.

(3) High-alumina refractory bricks, composed of corundum, mullite, and glass phase. The content of these minerals depends on the AL2O3/SiO2 ratio, as well as the type and quantity of impurities. The grades of refractory bricks can be classified based on the AL2O3 content. The raw materials include high-alumina bauxite and natural ore of sillimanite type, with some also incorporating electric fused corundum, sintered alumina, synthetic mullite, and clinker produced by firing alumina and clay in different proportions. Most are produced using the sintering method. However, the products also include cast bricks, sintered grain bricks, unburned bricks, and不定形refractory bricks. High-alumina refractory bricks are widely used in the iron and steel industry, non-ferrous metal industry, and other industries.

(4) Corundum refractory bricks, which refer to refractory bricks with an AL2O3 content of not less than 90% and corundum as the main phase, are divided into sintered corundum bricks and electric fused corundum bricks.