Steel Ladle Working Condition
Steel ladle is important steelmaking equipment, its main function is storage and delivery of liquid steel, sometimes, it is also used as secondary refining furnace. Based on steelmaking processes, steel ladles are classified into mould casting ladles and continuous casting ladles. The working condition of steel ladle is: high temperature steel liquid (about 1650℃) thermal impaction, mechanical abrasion, molten slag and steel liquid chemical corrosion, especially damage to ladle bottom is the severest. Besides, steel ladle works periodically, temperature difference is very large, thermal recycling is frequent, which greatly affects the life of steel ladle. With the development of continuous casting and vacuum technique, the working condition of steel ladle is more and more harsher, steel liquid temperature is further increased, steel liquid storage time is longer. Therefore, there are higher requirement on steel ladle refractory material. High alumina bricks and fireclay bricks are gradually replaced by alumina magnesia castable and alumina magnesia carbon castable.
1. Mold Casting Steel Ladles Castable
Converter steelmaking turnaround time is shorter, especially for small converter for construction steel production, steel liquid supply is sufficient, ladle lining temperature difference is smaller. The working condition of converter steel ladle is not as bad as continuous casting ladle, water glass bonded alumina magnesia castable, bauxite magnesia castable, bauxite spinel castable, silicon micro powder bonded high alumina castable can be used in converter steel ladles.
2.Mold Casting Steel Ladle Castable Physiochemical Index
| Item |
Alumina magnesia castable |
Alumina magnesia castable |
High alumina castable |
| Application |
Work lining |
Work lining |
Permanent lining |
| Al2O3 %≥ |
60 |
70 |
60 |
| MgO % ≥ |
12 |
10 |
/ |
| C % |
/ |
/ |
/ |
| Refractoriness ℃≥ |
/ |
/ |
1790 |
| RUL ℃ ≥ |
1200 |
1350 |
/ |
| LCR % (1400℃,2h) |
0~2 |
0~2 |
0~0.3 |
| Apparent porosity % ≤ |
23 |
25 |
18 |
| CCS MPa ≥ |
30 |
30 |
30 |
| Max. working temperature ℃ |
1700 |
1700 |
1650 |
3. Continuous Casting steel ladle castable
Converter continuous casting steel ladle’s turnover speed is faster, temperature fluctuation is smaller and working condition is better. So for small size converter ladles, bauxite magnesia castable is used to construct integral lining and can be patched to prolong service life.
For middle size and large scale ladles, corundum magnesia castable and corundum alumina magnesia spinel castable are usually used as ladle wall and bottom working lining. Slag line zone is usually built by magnesia carbon bricks. Castable which can be worked by gunning casting have been applied in some countries and have obtained very nice effect. Gunning castable includes alumina magnesia gunning castable, magnesia gunning castable, magnesia spinel gunning castable and so on.
4.Continuous Casting Steel Ladle Castable Index
| Item |
Alumina magnesia castable |
Alumina magnesia castable |
| Application |
KIP gunning machine |
CAS tube |
| MgO %≥ |
2 |
5.7 |
| Al2O3 %≥ |
90 |
90 |
| F.C % |
/ |
/ |
| Apparent porosity % |
/ |
/ |
| Bulk density g/cm3 ≥ |
3.00 (110℃) |
3.10 110℃) |
5. Al2O3-MgO-C series Steel Ladle Castable
With the rapid development of steel smelting technique, especially with the application of continuous casting and secondary refining techniques, the requirement on ladle refractory material is much higher. So alumina magnesia carbon castable which has good chemical corrosion resistance washing resistance, slag erosion resistance, thermal shock resistance and high mechanical strength is developed. Al2O3-MgO-C castable can produce magnesia alumina spinel and significantly enhance corrosion resistance and spall resistance of refractory material, greatly prolong the service life of steel ladle.
6. Steel Ladle Alumina Magnesia Castable
To shorten construction time, improve working condition and reduce refractory material consumption, currently, alumina magnesia castable are gradually used in steel ladle, the lining service life can reach to 60 times or more, refractory material consumption is reduced by 60%~80%. Under the action of high temperature steel liquid, MgO and Al2O3 in the castable can react and form alumina magnesia spinel, which has better liquid steel and molten slag corrosion resistance.
7. Alumina Magnesia Spinel Castable
Bauxite based alumina magnesia spinel castable contains certain ratio of magnesia alumina spinel, which makes castable’s corrosion resistance and spall resistance ability improved greatly, the performance is better than water glass bound alumina magnesia castable and get excellent using effect in all kinds of steel ladles. Bauxite based alumina magnesia spinel castable ‘s service life is 2-4 times of water glass bound alumina magnesia castable.
