Paving slabs are widely used in life due to their excellent properties, but they are not so easy to produce paving slabs. During the firing process, many requirements are met, such as temperature conditions. The following describes how to control the temperature during firing of sintered paving slabs.
The firing of sintered paving slabs is a key part of the brick making process. Generally, the firing temperature is controlled between 900 and 1100 ° C, so that the brick is sintered until it is partially molten. If the firing temperature is too high or the time is too long, fire bricks are liable to occur. Fire bricks are characterized by deep color, crisp percussion, and large deformation. If the firing temperature is too low or the time is insufficient, underfire bricks are liable to occur. Low fire bricks are characterized by light color, dull percussion, low strength, high water absorption, and poor durability.
When firing in a brick kiln, it is an oxidizing atmosphere, and the bricks appear red due to the formation of iron trioxide, which is called red bricks. If it is sintered in an oxidizing atmosphere and then sintered in a reducing atmosphere, the red iron oxide is reduced to blue-gray ferrous oxide, which is called green brick. Blue bricks are generally denser, more alkali-resistant and more durable than red bricks, but due to their high price, they are currently produced and used less frequently.
In addition, industrial wastes such as coal slag and high carbon content fly ash can be blended into the soil of the billet to produce internal combustion bricks during production. When the brick is roasted to a certain temperature, the carbon in the waste residue is also incinerated in the dry body, so it can save a lot of fuel and 5% -10% clay material. Internal combustion bricks are uniformly incinerated, have low apparent density, low thermal conductivity, and strength can be improved by about 20%.