The difference between low porosity high alumina brick and high alumina brick is that the porosity is low.

 

Generally, high alumina bricks are divided into grade I, II and III, and various grades of high alumina bricks are produced according to different indicators. The anti spalling high alumina brick is added with zirconium, and the low porosity high alumina brick is a special high alumina brick with low porosity and good thermal shock.

 

Generally, the porosity of high alumina brick is about 22-24%, and that of low alumina brick is less than 18-19%. Therefore, the porosity is slightly different, mainly for machines with different pressures during high-pressure forming, but the thermal shock is the same.

 

The firing time and humidity of low air hole high alumina brick are also different from that of general high alumina brick. The firing time of general high alumina brick kiln car is 60-70 minutes, while that of low air hole high alumina brick kiln car is more than 80 minutes. In this way, the load softening temperature of the two kinds of high alumina bricks is also different.

 

Because the low porosity high alumina brick needs to add specific matrix materials, and the firing temperature is also higher than that of the general high alumina brick, the compressive strength is also different.

 

Generally, some high alumina bricks have low temperature demand, and some add a small proportion of waste high alumina bricks, so there are great differences in production costs.

 

Low porosity high alumina brick is used in the lining of special kiln, and the erosion of atmosphere in the kiln also has high requirements for high alumina brick. Therefore, low porosity high alumina brick not only has low porosity, wear resistance, fatigue resistance, but also has good corrosion resistance. However, compared with general high alumina bricks, the price will be relatively high.

 

In short, the internal quality of general high alumina brick and low air hole high alumina brick is different. The use can be determined according to different situations.