Firing method for lightweight silica bricks

The firing method of lightweight silica bricks mainly includes the following steps:

Raw material preparation: the preparation of lightweight silica bricks usually uses finely crushed silica as the main raw material, and its critical particle size is usually not more than 1mm, of which not less than 90% of the particles less than 0.5mm. In addition, it is also necessary to add the appropriate amount of flammable substances or the use of gas generation method to form a porous structure.

Forming: After mixing the prepared raw materials evenly, it can be formed by vibration molding or pounding. After molding, the blanks need to be dried at 110℃ for 4~24 hours to ensure the stability and strength of the blanks.

Firing process: The firing process is carried out in several stages. First, preheating and constant temperature treatment at lower temperatures, gradually warming up to the high temperature stage. Specific steps include:

20~200℃ warming period of 5 days, warming rate of 1.5℃/h, 200℃ constant temperature for 5 days.

200~300°C warming period 4 days, warming rate 1.0°C/h, 300°C constant temperature 5 days.

300 ~ 600 ℃ heating period of 10 days, the heating rate of 1.25 ℃ / h, 600 ℃ constant temperature for 6 days.

600 ~ 800 ℃ heating period of 4 days, the heating rate of 2 ℃ / h, 800 ℃ constant temperature for 2 days.

800 ~ 1000 ℃ warming period of 1 day, and then turn the blast furnace gas normal burner, so that the hot stove as a whole to further complete the baking, the temperature continues to rise in a balanced manner, to reach the level of wind temperature required by the blast furnace.

Characteristics and application of lightweight silica bricks: lightweight silica bricks have a uniform microstructure, low bulk density, excellent thermal insulation and heat preservation performance, high loading softening temperature, high temperature volumetric stability and other characteristics. It is mainly used for the requirements of thermal insulation or reduce self-weight without direct contact with molten material, not subject to erosive gases, not subject to rapid changes in temperature of the various parts of the kiln.