Properties and performance indicators of clay bricks

The properties of clay products fluctuate in a large range, which is due to the large range of fluctuations in the chemical composition of the products (AI203 content ranges from 30 to 46%) and differences in production processes.
 
The fire resistance of clay products fluctuates from 1580 to 1770C. It mainly depends on the chemical composition of the product, which increases with the increase of the AI203 / Si02 ratio. The increase in flux impurities, especially alkali metal oxides, will significantly reduce the fire resistance of the product. The softening temperature of the load mainly depends on its chemical mineral composition and density, but the latter does not affect the end temperature of the softening of the load, but increases the starting deformation temperature. The lower bulk density of bricks will also lower the temperature at which the load begins to soften. Therefore, in order to increase the load softening start temperature of clay products, the following aspects should be generally considered:
Increase the Al203 content in the product, especially increase the AI203 content of the matrix; increase the firing temperature and the use of multiple clinker ingredients; increase the bulk density of the shaped brick.
Clay bricks have good thermal shock resistance and a large fluctuation range, which are generally greater than 10 times (1100C water-cooled).
It is related to the linear expansion coefficient value of the clay products is not too large (the average linear expansion coefficient between 20 and 1300C is 4.5X10-6-5.8X 10-6 / C), and there is no phenomenon of polycrystalline brick deformation and obvious grain structure. .
Clay products are weakly acidic refractory products, and their acidity increases with increasing sio2 content. It has a certain resistance to acidic erosion, but has a poor resistance to alkaline erosion. Therefore, clay products are suitable for acid furnace kiln refractories. Large-scale clay refractory bricks for glass kiln are clay refractory bricks with a unit weight of not less than 50 kg for glass kiln.