The requirements of refractory high alumina brick for coke kiln

Jul 13,2017
High aluminum refractory bricks in the aluminum silicate refractory AL2O3 content of more than 48% of the refractory products. According to the composition of the main minerals in the product, the high-alumina refractory products are divided into mullite-corundum, corundum-mullite, mullite and corundum. If the content of AL2O3 content, the general use of high alumina brick is divided into three grade, that is, first grade AL2O3> 65%; second grade AL2O355% ~ 65%; third grade AL2O348% ~ 55%.
(1) high refractory refractory refractory bricks, the refractoriness in the aluminum silicate refractory material is relatively high, with the product in the AL2O3 content increased refractoriness increased, generally not less than 1750 ~ 1790 ℃. Such as AL2O3 content of more than 95% corundum products, the fire resistance can be as high as 1900 ~ 2000 ℃.
(2) The softening temperature of the high alumina refractory bricks decreases with the increase of SiO2 and metal oxide content in the products. Generally, the softening temperature of high alumina bricks is 1420 ~ 1530 ℃. While the AL2O3 content of more than 95% corundum products, the load softening temperature of 1600 ℃ or more.
(3) high aluminum refractory bricks slag resistance, because the products in the high content of AL2O3 and neutral, so the acid or alkaline slag have a strong resistance to erosion.
(4) high thermal resistance of high-alumina refractory bricks, in its products in corundum and mullite two kinds of crystal coexistence, and corundum linear expansion coefficient than mullite linear expansion coefficient is large, so the temperature change him Due to differences in the expansion of the product caused by stress concentration, so the high thermal resistance of aluminum brick is poor, the general number of water cooling only 3 to 5 times.
(5) high-alumina refractory baking line changes, according to the degree of firing products may be. If the firing temperature is enough, when firing enough Yan, the volume is stable, the re-burning line changes small. Conversely, due to the occurrence of recrystallization within the product, it will lead to residual shrinkage.

In view of the high alumina refractory bricks with the above characteristics, it is mainly used for building coke oven burner burner and carbonization chamber at the bottom of the burner and other parts, but should not be used as charcoal chamber wall tiles, due to high temperatures will produce curling, and many more.