When purchasing high alumina refractory bricks, you can quickly make a preliminary judgment on their quality by observing their appearance and comparing their weight.
Appearance
The surface of high-quality high alumina refractory bricks is smooth and clean, without obvious cracks, missing edges or impurities. If the surface of the brick is rough, with long and thin cracks, large areas of missing corners or dense pores, and spots of different colors, it is mostly a process defect. It is easy to crack or be corroded at high temperatures, affecting its performance and life in high temperature environments. High-quality bricks have uniform color without obvious spots or color differences. Mottled and uneven may be caused by poor raw material mixing or uncontrolled sintering.
Weight Level
The density of high alumina refractory bricks is proportional to the alumina content. Under the same size, high-quality bricks feel heavier, and the weight difference of single bricks in the same batch is small. You can randomly select a few bricks to weigh. If the weight fluctuates greatly or is obviously too light, it may be that the interior is loose and the porosity is high. In addition, if you tap the brick body with your hand, if the sound is crisp and loud, the structure is dense. If the sound is dull and hoarse, there may be internal hidden dangers.
On-site Simple Test
The water absorption rate can be used to assist in judgment. Soak the brick sample in water for 24 hours. If the water absorption rate exceeds 8%, the slag resistance is poor and the quality is worrying.
Although the above method is not a professional test, it can quickly screen out obviously inferior high alumina refractory bricks. Combined with the manufacturer's qualifications and quality inspection reports, the quality can be controlled more comprehensively.