Selection Method of Refractory Lining for Different Parts of Blast Furnace

In the production process, the refractory lining of the furnace wall by a variety of role and gradually be eroded, so the choice of the various parts of the refractory brick lining should follow the principle is: refractory lining lining with the part of the heat flow intensity corresponds to, To keep the brick under the impact of strong heat flow

Lining to maintain integrity and stability; refractory lining with the part of the erosion mechanism should be corresponding to ease and delay the lining damage rate, to extend the life of blast furnace; try to use the price / performance than the low refractory, the choice of price Relatively low performance and good resistance

Firebrick, should not blindly choose expensive high-grade refractories. Each part of the firebrick lining selection method is:
(1) furnace throat. Mainly into the charge of the impact and wear, the general selection of steel or water-cooled steel bricks.
(2) the upper part of the furnace. This area is prone to carbon deposition reaction area, and alkali metal, zinc vapor erosion is also occurring in the region, together with the decline in charge and rising gas flow erosion and wear, it should be used to resist chemical erosion and abrasion resistance Of the refractory material

Material, the most suitable high-density clay brick, high-density third-class high-alumina brick or phosphoric acid-impregnated clay brick. Modern large-scale blast furnace on the use of thin-walled structure, the commonly used 1 to 3-stage buckle instead of brick wall lining.
(3) in the lower body and furnace waist. The main mechanism of damage is thermal shock, high temperature gas scour, alkaline metal, zinc and carbon analysis, as well as the initial chemical erosion of slag. Brick lining should be used for thermal shock resistance, resistance to early slag erosion and erosion of refractory castable Now at home and abroad

Large blast furnace selection of good performance but expensive silicon carbide brick (silicon nitride combination, self-bonding, combination of SIAL), so that the life of more than 8 years. Practice has proved that even the best refractory used for Blast Furnace is to be eroded, to balance (probably erosion to the original thickness of half

) Can be stable, this time is about 3 years. In fact, the use of good performance of fired aluminum carbon brick (much cheaper), can achieve this goal. So 10003 and below the blast furnace can be used aluminum carbon brick.
(4) furnace belly. The main reason for the damage is the scouring of high temperature gas and the scouring of slag iron. The heat flux of this part is very strong. Any refractories can not be resisted for a long time, mainly in slag skin, so this part need not be selected.
Too expensive refractories. This part of refractory company life is not long (1-2 months is long, short is 2-3 weeks), the general selection of high refractoriness, load softening temperature and high bulk density refractories, such as high alumina brick, aluminum carbon brick Wait.
(5) hearth tuyere area. This site is the only area of ​​the blast furnace oxidation reaction, the resulting high temperature up to 1900 ~ 2400), brick lining by high temperature caused by the destruction of thermal stress, and high temperature gas scouring, slag erosion, alkali metal erosion, cyclic movement coke

Of the erosion and so on. Modern blast furnace are combined brick masonry tuyere area, made of high aluminum, corundum mullite, corundum and silicon nitride silicon carbide, etc., but also useful for hot-pressed carbon block.
(6) hearth bottom and bottom. Blast furnace lining erosion of serious areas, the degree of erosion has always been to determine the basis for the generation of blast furnace life. The early bottom of the furnace because no cooling, mostly using a single ceramic refractories, thermal stress so that masonry cracks, hot metal

Penetration into the seam leaving the furnace floor brick is the main reason for the damage. The use of good bottom structure (ceramic cups, staggered bite, etc.) and cooling, as well as the use of high quality corundum, gray corundum bricks and carbon microporous, hot pressed bricks, greatly prolongs the blast furnace bottom life. but

Is the molten iron on the carbon brick osmotic corrosion, chemical corrosion of alkali bricks on the carbon brick, thermal stress on the destruction of carbon brick, C02 and H20 on the oxidation of carbon brick is still a threat to the hearth, furnace life important factors, and iron The circulation of the molten iron at the time of the movement on the cylinder liner lining the circumference of the machinery

Scouring and erosion are the primary factors of hearth damage.
This part of the refractory using high thermal conductivity, high permeability, high chemical resistance, low porosity, small pore size hot-pressed small carbon bricks, microporous carbon brick, carbon brick and hot-pressed semi-graphite used in ceramics Cups of corundum or gray corundum bricks. In a very long period of time

Time, small and medium-sized blast furnace using electric calcination anthracite made of high quality self-baking carbon block also achieved very good results. But changed to ceramic cup structure, you should not use self-baking carbon block, and use a roasted carbon block. Because the ceramic cup structure on the high-alumina refractory insulation

Self-baking carbon brick loss of self-baking conditions, can not make self-baking carbon brick to form a whole, so there have been several production burnout accident (North Taiwan, etc.).
Tiekou District, poor working conditions, and now the furnace with refractories matched the combination of iron brick masonry, the production of carbon, semi-graphite, mullite and so on.