Silica bricks for hot blast stove

Silica bricks for hot blast stove

Silica refractory brick is an acidic refractory mainly composed of tridymite, cristobalite and a small amount of residual quartz and glass phases

The silica content is more than 94%. The true density is 2.35g/cm3. It has resistance to acid slag erosion. Higher high temperature strength.

The starting temperature of softening under load is 1620~1670℃. Long-term use at high temperatures will not deform.

The raw material for making silica bricks is silica. The higher the SiO2 content of the silica raw material, the higher the refractoriness.

It is mainly used for the partition wall of the carbonization chamber and the combustion chamber of the coke oven, the regenerator and the slag chamber of the steel-making open-hearth furnace, the refractory silica brick material of the soaking furnace, the glass melting furnace and the ceramic firing kiln. and other load-bearing parts. It is also used for high temperature load-bearing parts of hot blast stoves and acid open hearth furnace tops.

Features of silica brick:

1. Silica brick for coke oven

Silica bricks for coke ovens are made of tridymite as the main crystal phase and are used to build coke oven siliceous refractory products. A modern coke oven is a large thermal equipment built with tens of thousands of tons of refractory materials of nearly 1,000 types of bricks, of which the amount of silica bricks accounts for 60%-70%. Coke oven silica bricks used for masonry coke oven silica bricks should have the following characteristics:

(1) The softening temperature under load is high.

The coke oven silica brick must withstand the dynamic load of the coal loading truck on the top of the furnace at high temperature, and requires long-term use without deformation, so the coke oven silica brick is required to have a high softening temperature under load.

(2) High thermal conductivity. Coke is made from coking coal in the carbonization chamber by heat transfer from the kiln wall of the combustion chamber, so the silica bricks used to build the combustion wall should have high thermal conductivity.

(3) Good thermal shock resistance. Since the coke oven needs to periodically charge coal and discharge coke, the temperature of the silica bricks on both sides of the combustion chamber wall changes drastically, so the coke oven silica bricks are required to have good thermal shock resistance.

(4) High temperature volume stability. The grade of silica brick for coke oven is JG-94, and the product standard is YB/T5013-1997.

2. Silica brick for hot blast stove

With the increase of the air temperature of the hot blast stove, the use conditions of the refractory materials for the hot blast stove are becoming more and more severe. When the air temperature is higher than 1200 ℃, the traditional high-aluminum products can no longer meet the requirements of their high-temperature parts. At high temperature, silica brick has the advantages of low creep rate, high strength and good thermal shock resistance, so silica brick is widely used in the roof, partition wall and upper part of the regenerator of large hot blast stoves.

The grade of silica brick for hot blast stove is RG-95, and the product standard used is YB/T133-1998.

3. High-quality silica bricks for glass kilns

High-quality silica bricks for glass kilns have the characteristics of high silicon oxide content and low melting index, and are mainly used in the upper structures of glass kilns such as ceilings, breast walls, hanging walls, small furnaces, and regenerators.