Hot blast stove is one of the important auxiliary equipment of blast furnace. The general requirements for hot blast stove are: to achieve high air temperature and longevity

The parts of refractory materials for hot blast stoves include large walls, vaults, regenerators, partition walls, combustion chambers, and ceramic burners. It can be divided into high temperature area and low temperature area. The working environment of these parts:

1. Hot blast stove lining and checker bricks are often affected by rapid cooling and rapid heating changes

2. Corrosion by alkali metals

3. The hot blast stove itself is affected by the load

High temperature area:

High temperature effect of 1200-1350°C; effect of sharp temperature change during heat exchange; chemical attack effect of blast furnace gas into dust

Erosion effect of combustion gas; mechanical load effect, etc.

Therefore, the general requirements when selecting refractories are: good creep resistance, good volume stability at high temperature, high softening temperature under load, and good corrosion resistance.

Medium and low temperature area:

The selected refractory material has large heat capacity, good hot air conductivity, low air permeability, high density, high strength and good thermal shock stability.

The selection of refractory materials for hot blast stoves is mainly determined by the temperature of the hot air. When the temperature of the hot air is lower than 900°C, clay bricks are generally used for masonry, and some have a service life of up to 20 years. When the air temperature is higher than 900°C, High-alumina bricks, mullite bricks, sillimanite bricks and silica bricks are used for furnace linings and lattice bricks at high temperature. Of course, economic factors such as the price of materials must also be considered.

Different refractory materials are used for blast furnace hot blast stoves in various factories in various places, but there is one thing in common. When choosing refractory materials, you must pay attention to:

1. High temperature load creep resistance of refractory material 2. Volume stability and thermal expansion performance of refractory material 3. Heat exchange efficiency of hot blast stove

The refractory bricks used in each part of the hot blast stove are as follows:

High temperature in the upper part of the big wall: use silica brick, mullite brick; middle and lower part: use high alumina brick, sillimanite brick and clay brick

Vault area over 1400°C: use silica brick, mullite brick, sillimanite brick, andalusite brick or low creep high alumina brick

Regenerative upper part: siliceous lattice brick; middle part: low creep high alumina brick, mullite brick, sillimanite, andalusite brick; lower part: clay brick

Partition wall: the same refractory material used in the combustion chamber

Combustion chamber: high temperature area: silica brick, mullite brick, low creep high alumina brick, medium and low temperature area: high alumina brick and clay brick

Burner: Ceramic burner, mullite.