Chemical index Al2O3,%: ≥ 48

Chemical index Fe2O3: ≤ 2

Refractoriness ℃: ≥ 1750

Bulk density g / cm3: 2.25-2.35

Compressive strength: cold crushing strength MPa: ≥ 39

Application field of high alumina brick: in the actual test, the first and second grade high alumina bricks are mostly used in tunnel kilns with a temperature of 1500-1600 ° C, blast furnace, furnace top, reverberatory furnace, rotary kiln lining and many other kilns.

According to the difference of Al2O3 content in high alumina brick, 48%, 55%, 60%, 65%, 73%, 75% and 80% are often used at present.
According to the content of less than 55 called clay brick, is a kind of neutral refractory, made of bauxite or other materials with high alumina content. With high thermal stability and fire resistance temperature of 1700 ° C, it is used for lining of glass furnace, cement rotary kiln and steel-making electric furnace. Of course, there are also some high alumina clay bricks with high load, low creep and low porosity. The finished products of high alumina bricks are very important for the proportion of raw materials in the production according to different application needs.

The alumina content of high alumina brick and clay brick is not only different, but their production process is similar. However, the addition of clinker is relatively high, which can reach 90-95%. The firing temperature is also much higher than that of clay brick. In the actual test, the first and second level high alumina brick are mostly used in tunnel kiln with temperature of 1500-1600 ° C, blast furnace, furnace top, reverberatory furnace, rotary kiln lining and many other kilns.

Project	Index
International Code Name	SK35	SK36	SK37	SK38	SK40
Chinese Code Name	LZ-48	LZ-55	LZ-65	LZ-75	LZ-80
Al2O3 ,%	≥48	≥55	≥65	≥75	≥80
Fe2O3, %	≤2	≤2	≤2	≤2	≤2
Refractoriness ℃, min	1750	1770	1790	1790	1790
Apparent porosity%	≤22	≤22	≤23	≤23	≤21
Bulk Density g/cm3	2.25-2.35	2.25-2.35	2.25-2.35	2.25-2.35	2.25-2.35
Cold Crushing Strength Mpa	≥39	≥44	≥49	≥54	≥65
Load softening temperature 0.2MPa refractoriness under load t0.2 ℃, min	≥1420	≥1470	≥1500	≥1520	≥1530
Permanent linear change on reheating （%）1500℃X2h	+0.1~-0.4 x1450℃	+0.1~-0.4	+0.1~-0.4	+0.1~-0.4	+0.1~-0.4