Causes of reticular cracks in high-alumina refractory bricks

Reticulated cracks on the surface of high alumina bricks are often shortcomings in the production of high alumina bricks. The reasons for the occurrence of reticulated cracks are more complicated. The impurity content of the clinker (especially the R2O content), the degree of sintering, the critical particle size, the amount of fine powder, the mixing quality of the mud, the humidity and temperature of the dry medium of the green body, the shortening of the green body during the firing process, and The secondary mullite chemical reaction and the corundum recrystallization effect, etc., will cause the appearance of the product to appear reticulated. The sintering of high alumina bricks is liquid phase sintering. The composition temperature and amount of the liquid phase, the heating rate during sintering and the atmosphere conditions are also important factors that lead to inconsistency and shortening, and the formation of surface network cracks.