The problems of large-size high alumina bricks in the production process are as follows:
① In terms of production molding, the compressive strength of machine molding can not be reached, and the compressive strength of manual tamping can only reach 30% of machine molding. The pressure of high alumina brick is not enough, and the density is naturally low.
② Sintering problem: for large-scale high alumina bricks, due to the length or width of the brick surface, cracks of different lengths will appear on the brick surface after sintering in high-temperature tunnel kiln, which is related to the allocation of raw materials, excessive size of bricks, sintering degree and wind crack. So we usually see a lot of big bricks with a few surface cracks.
In conclusion, the longer dimension of high alumina brick must be proportional to the width and thickness, and can not be combined with the actual production situation, otherwise the produced high alumina brick will not meet the use requirements.