Product Description of Fused And Bonded Magnesia-chrome Bricks For RH Furnace
Currently, the refractory materials used for RH furnaces are primarily magnesia-chrome bricks. Compared with other ladle refining equipment, the refractory materials used in different parts of the RH vacuum chamber are not only subjected to the erosion of high-temperature molten steel and slag during processing but also endure high-speed scouring by molten steel and rapid temperature fluctuations.
Therefore, higher demands are placed on the refractory materials. However, with the increase in refining intensity and the continuous variation of steel grades, the service life of existing magnesia-chrome bricks can no longer meet the requirements for energy saving and consumption reduction. To address this issue, high-performance fused rebonded magnesia-chrome bricks have been developed based on the original magnesia-chrome bricks and have been successfully applied in Baosteel's furnaces, achieving good results.
Fused Rebonded Magnesia-Chrome Bricks for RH Furnaces
To improve the performance of the existing magnesia-chrome bricks, high-purity, high-Cr2O3-content fused magnesia-chrome sand and chromite were selected as the main raw materials. The effects of Cr2O3 content, as well as the addition of high-purity magnesia, TiO2, Cr2O3 micro-powders, and other additives, on the performance of magnesia-chrome bricks were studied. The chemical composition of the main raw materials is shown in Table 1.
| Item | RS-FRM Ge-12 | RS-FRM Ge-14 | RS-FRM Ge-16 | RS-FRM Ge-18 | RS-FRM Ge-20 | RS-FRM Ge-22 | RS-FRM Ge-26 |
| MgO (%) ≥ | 68 | 65 | 60 | 58 | 55 | 50 | 45 |
| Cr2O3 (%) ≥ | 12 | 14 | 16 | 18 | 20 | 22 | 26 |
| SiO2 (%) ≤ | 1.2 | 1.4 | 1.4 | 1.5 | 1.5 | 1.5 | 1.5 |
| Apparent Porosity (%) ≤ | 16 | 16 | 16 | 16 | 16 | 16 | 16 |
| Bulk Density (g/cm³) ≥ | 3.00 | 3.05 | 3.08 | 3.10 | 3.15 | 3.20 | 3.25 |
| Cold Crushing Strength (MPa) ≥ | 50 | 50 | 50 | 50 | 50 | 50 | 50 |
| Refractoriness Under Load (℃) | 1700 | 1700 | 1700 | 1700 | 1700 | 1700 | 1700 |
