Low creep high alumina bricks is produced on the basis of three stones (kyanite, andalusite and silimanite) theory, therefore, the chemical composition of low creep high alumina brick is similar to that of mullite. The raw materials of low creep high alumina bricks are high grade bauxite, binding clay, three stones, active alumina, etc. The ratio of Al2O3 and SiO2 is the key for the total transformation of mullite, so raw materials should be formulated accurately. As mullite has high very good high temperature performance, low creep high alumina bricks also have good high temperature properties.
Low Creep High Alumina Brick Characteristics
1.Good thermal shock resistance.
2.Good abrasion resistance.
3.Good corrosion resistance.
4.Good high temperature mechanical strength.
5.Good volume stability, low creep rate.
Low Creep High Alumina Bricks Technical Index
|Al2O3, % ≥||70||75||80||65||55||48|
|Refractoriness ℃ ≥||1790||1790||1790||1790||1770||1750|
|Apparent porosity % ≤||20||20||19||24||24||24|
|Cold crushing strength MPa ≥||65||70||80||49||44.1||39.2|
|Reheating linear change rage % ≥||±0.1||±0.1||±0.1||+0.1~-0.4||+0.1~-0.4||+0.1~-0.4|
|refractoriness under load (0.2Mpa) ℃ ≥||1500||1550||1650||1500||1470||1420|
|Creep rate % ≤||0.6
Low Creep High Alumina Bricks Applications
Although high alumina bricks have very high refractoriness, their refractoriness under load is relatively low. Low creep high alumina bricks have higher mullite content and lower glass phase, so they have higher thermal shock resistance, lower creep rate and higher refractoriness under load. Low creep high aluminum bricks are widely used in high temperature industrial kilns and furnaces. For example, inner lining of hot blast furnaces, glass melting tank where doesn’t contact with glass liquid, regenerator checkerwork and so on.