Hot blast furnace is a kind of thermal equipment which heats the air blasted into blast furnace from room temperature to high temperature. Hot blast furnaces can be divided into internal combustion type and external combustion type, the furnace body consists of regenerator chamber and combustion chamber.
The mixed blast furnace coal gas and coke furnace gas is usually used as hot blast furnace fuel, and can heat the air to 1300-1600℃. The hot blast furnace masonry will shrink and cause crack under the function of mechanical and high temperature thermal shock action, which will affect the service life of the hot blast furnace greatly.
So, refractory material used in hot blast furnace should have large thermal capacity, good creep resistance, high refractoriness under load, excellent high temperature strength and nice thermal shock resistance. When the temperature of the hot air is under 900℃, clay bricks which is economical can meet the requirement. When the temperature of the hot air is between 900~1100℃, high temperature zone lining and checker bricks should adopt high alumina bricks, mullite bricks and silimanite bricks. When the hot air temperature is between 1100~1200℃, high temperature part lining and checker bricks should use high alumina bricks, mullite bricks, silimanite bricks or silica bricks. When hot air temperature is above 1200℃, high temperature part lining and checker bricks should use premium silica bricks, mullite bricks and silimanite bricks. What should be mentioned is that more and more small and middle scale hot blast furnace in China are using high strength and low creep refractory ball.
High strength and low creep refractory ball has those advantages: 1. large specific surface area, strong heat storage ability, high thermal efficiency, significantly enhance energy saving effect and hot air temperature. 2. Easy and convenient for masonry, labor and time saving. 3. Solved the problem of cohesion.
Refractory Materials Used in Large Scale Hot Blast Furnaces
| Item | Corundum mullite brick | Clay brick | Silica brick | Alumina insulating brick | Silica insulating brick |
| Application | Hot air pipe, regenerator chamber checker brick | Combustion chamber, hot air main pipe | Regenerator chamber, combustion chamber, checker brick upper part | Regenerator chamber, combustion chamber, air mixing chamber | Regenerator chamber, combustion chamber |
| Al2O3 % | 71 | 45.5 | 69 | ||
| SiO2% | 95.9 | 94 | |||
| AP% | 18 | 22 | 21 | 52.5 | |
| Bulk Density g/cm3 | 2.55 | 2.12 | 2.32 | 0.98 | <1.15 |
| CCS/MPa | 96.2 | 35.7 | 35.5 | 3.4 | 6.6 |
| Refractoriness/ ℃ | 1790 | 1750 | 1710 | 1790 | 1690 |
| RUL ℃ | ≥1660 | 1390~1460 | 1680~1690 | ≥1400 | |
| Creep rate % | 1500℃ 0.17 | 1200℃ 0.58 | 1000℃1.1~1.3 |
| Item | Silica insulating mortar | SiC castable | Mullite brick | High alumina insulating brick | High alumina mortar |
| Application | For silica insulating brick masonry | Regenerator chamber and combustion chamber upper part | Regenerator chamber middle part air mixing chamber | Regenerator chamber and combustion chamber middle part | For masonry of corundum mullite brick |
| Al2O3 % | 83 | 62.4 | 87 | ||
| SiO2% | 92 | 95.9 | 94 | ||
| AP% | 18 | ||||
| Bulk Density g/cm3 | 1.31 | 2.25 | 2.72 | 0.65 | |
| CCS/MPa | 79 | 2.2 | |||
| Refractoriness/ ℃ | 1690~1710 | 1600 | >1790 | 1790 | ≥1850 |
| RUL ℃ | 1720 | 1660 |
RS Kiln Refractory Advantages in High Temperature Refractory Material
Established in the early 1990s, Rongsheng Kiln Refractory has more than 20 years of refractory material research and production experience. RS company can manufacture varieties of refractory materials for metallurgy, cement & refinery & chemical industry. Dedicated to providing high quality refractory products, RS Refractories supplier has earned a good reputation and built long-term cooperation relationships with many customers around the world.
