Sintering Machine Refractory
Pellet firing machine is thermal equipment in which iron concentrate, binder and flux mixture is sintered into pellets at 1300℃ high temperature oxidizing atmosphere. Sintering furnaces are divided into shaft furnace, belt sintering machine and grate-rotary kiln. Shaft furnace is consisted of furnace body, combustion chamber and flame channel.
Sintering machine top is built by high alumina special shaped bricks and wave-shaped fireclay bricks, sidewalls are made by high alumina bricks, front and back wall, burner nozzle surrounding and inspection hole are also made by special shaped high alumina bricks. Coating mix, plastic mix and castable made from similar materials can also be used at corresponding up mentioned parts. Furnace body insulating lining is usually constructed by diatomite bricks and fireclay insulating bricks. The rest parts of shaft furnace are all built by clay bricks.
Refractories used at other sintering machines are basically the same as shaft furnace, high alumina bricks and fireclay bricks are the most often used refractory bricks. But the application of integrally casted lining and pre-cast blocks are gradually increased, as well as refractory fiber products.
Sintering Machine Refractory Physiochemical Index
| Item | SJ-1 | SJ-2 | SJ-3 | SJ-4 | SJ-5 | SJ-6 |
| High alumina wearproof coating mix | Anti-wear insulating coating mix | Acid proof gunned material | High alumina plastic refractory | Clay insulating castable | High alumina castable | |
| Applications | Dust extraction pipe bend, confluence pipe | Ring cooler, chimney | 200m steel chimney | Sidewalls, furnace top, front and back walls | Furnace top outside part | Front and back sidewalls cooling water box |
| Al2O3 % | ≥75 | ≤16 | / | ≥60 | ≥34 | ≥63 |
| SiO2% | ≥10 | ≥60 | / | ≥35 | ≤41 | ≥30 |
| Fe2O3 % | / | / | / | ≤1.5 | / | ≤1.2 |
| CaO % | ≤10 | ≥16 | / | / | 25 | / |
| Bulk density g/cm3 | ≤2.53 | ≤1.47 | ≤2.0 | ≥2.42 | ≤0.85 | ≥2.42 |
| Cold crushing strength | ≥10.29 | ≥2.5 | ≥44 | ≥8.0 | ≥2.0 | ≥20 |
| Modulus of rupture Mpa | ≥4.41 | / | / | ≥3.50 | ≥0.8 | ≥5.8 |
| Refractoriness ℃ | / | 1260 | 1700 | 1000 | 1600 | |
| Reheating linear change rate % | ≤0.2 | ≤-0.1 | ≤0.1 | ≤-0.6 | 1.5 | ±0.3 |
| Thermal conductivity W/(m·K)350℃ | / | / | ≤0.75 | 0.85 | ≤0.17 | / |
| Item | SJ-7 | SJ-8 | SJ-9 |
| High alumina bricks | Fireclay bricks | SiC bricks | |
| Applications | Furnace top, front and back sides | Shaft furnace lining | Impacting plate |
| Al2O3 % | ≥55 | ≥40 | / |
| SiC % | / | / | ≥90 |
| Fe2O3 % | ≤1.8 | ≤1.5 | / |
| CaO % | ≤1 | / | / |
| Bulk density g/cm3 | / | / | ≥2.60 |
| Apparent porosity % | ≤24 | ≤20 | / |
| Cold crushing strength | ≥40 | ≥40 | ≥200 |
| Modulus of rupture Mpa | / | / | ≥35 |
| Refractoriness ℃ | ≥1770 | ≥1730 | |
| Reheating linear change rate % | 0.1~-0.4 (1450℃,3h) | 0~-0.4 (1450℃,2h) |