The steel liquid smelted in blast furnace will be poured out from tap hole, runs through the main channel, tapping channel and swing iron spout and finally flows into foundry ladle. There is are slag skimmer between the main channel and tapping channel, iron liquid flows into tapping channel under the slag skimmer while the slag stopped by the skimmer flows into slag channel.

Because blast furnace can be divided into large scale blast furnaces, middle and small sizes blast furnaces, the refractory materials used varies far from each other. For small size blast furnaces, with a volume bellows 1000m³,low price manually operated ramming mass and extra-low strength stemming are usually used. But for large scale blast furnaces, which’s volume is over 2000m³, high quality castable and stemming are used. Castable and stemming used in middle size furnaces is between the large scale ones and small size ones.

1. Small size blast furnace casting house refractory material

Refractory materials used in small size blast furnace casting house are hydrated alumina-silicon carbide-carbon ramming mass, carbon bonded alumina-silicon carbide-carbon ramming mass, alumina-silicon carbide-carbon ramming mass, alumina silicon carbide precast block, clay bricks, insulation bricks, alumina-silicon carbide-carbon stemming, etc. The formerly used patching materials for casting house are ramming mass containing clay, coke carbon powder, and low grade silicon carbide or that containing water. One patch of the main channel can only be used for 5~10 days, refractory materials consumption can reach higher than 2kg/t.Now, carbon bonded ramming mass be widely used and the main channel service life are prolonged to 10~14 days, sometimes, service life can be longer than 30 days. The tapping channel and slag channel’s service life can be longer than 1 month. The slag skimmer are usually built by high alumina silicon carbide ramming mass or precast block, the service life is about 2 months, sometimes, even longer than 90 days. The refractory materials consumption of the casting house is decreased to lower than 0.5kg/t.

2. Middle and large scale blast furnace casting house refractory materials

For middle and large scale blast furnace casting house, alumina silicon carbide carbon castable is usually used. The iron output of single time can reach 80~120 thousand tons, by grouting patching and casting patching, the service life can attain 1 million tons or more. Refractory materials used in different parts are as follows.

Main channel iron line and swing iron spout: high alumina castable, high alumina silicon carbide carbon ramming mass, high alumina silicon carbide bricks, insulation bricks

Main channel slag line :high alumina silicon carbide castable.

Main channel cover : High alumina silicon carbide carbon castable.  

Tapping channel: high alumina silicon carbide castable, high alumina silicon carbide brick, diatomite insulation brick.

Slag channel: high alumina silicon carbide castable, diatomite insulation brick.

In recent years, quick drying castable is developed to meet the fast patching of tapping channel. Self-flowing castable brings much convenience for the casting, especially with the invention of wet spraying castable, refractory materials consumption continues to decrease and iron output is correspondingly increased. Graphite ramming mass can enhance tapping channel corrosion resistance and service life, so carbon ramming mass, especially high carbon castable is a promising direction.