Lightweight insulation fire clay bricks are a kind of shaped refractory material with clay as the main raw material, which is processed, shaped, dried, and calcined with clay. on the kiln. Due to the requirements of the use environment, clay bricks must have a certain compressive strength, good thermal shock resistance, and good external dimensions.

 

With the continuous advancement of science and technology, users have higher and higher requirements for the strength of clay bricks. For example, the 70M rotary kiln of Pangang Metallurgical Materials Co., Ltd. and the lightweight insulation fire clay bricks used in the rotary kiln of Pangang Titanium Dioxide Factory have higher strength requirements of >50MPa. At present, the compressive strength of clay bricks is relatively low, generally between 25MPa and 40MPa. In order to develop high-strength clay bricks, Liu Yun et al. used coke gemstone and kyanite as raw materials, soft clay, semi-soft clay, and pulp waste liquid. As a binder, the ingredients are prepared according to the mass ratio of aggregate: powder = 55:45. In general, the critical particle size of clay bricks is 3mm, but in this experiment, the critical particle size of the aggregate is increased to 4mm, and the amount of coarse aggregate added is increased, so it not only improves the bulk density of the clay, it is easy to form, but also The sintering of the green body is promoted, the porosity of the product is reduced, the compressive strength and the softening temperature under load are improved, the thermal shock resistance is improved, the volume stability is increased, and the external dimension of the product is more accurate.

 

The results show that with the increase of kyanite addition, the bulk density of the sample increases, the porosity decreases, the compressive strength and softening temperature under load increase, and the linear shrinkage rate decreases. With the decrease of kyanite particle size, the bulk density of the sample increases, the porosity decreases, the compressive strength and load softening temperature increase, and the linear shrinkage rate increases. Considering various properties comprehensively, the best firing system for preparing clay bricks is (1405±5)℃×10h, and the best raw material ratio is: w (scorched gemstone)=70%～85%, w (kyanite) = 5% ~ 20%, w (bound clay) = 5% ~ 10%. On this basis, industrial production is carried out. Table 1 lists the performance indicators of the developed clay brick laboratory, industrial production, and foreign similar products.