Semi-rebonded magnesia-chrome brick is fired from partially fused magnesia-chrome sand. The main mineral composition of semi-rebonded magnesia-chrome bricks is periclase, spinel, and a small amount of silicate. The grains are of opaque structure, the spinel in the periclase crystal is fully developed, and the matrix part is of a metasomatic turbidity structure. The inter-crystal is the direct combination of periclase-periclase or periclase-spinel, and the silicate phase exists between the crystal grains in an isolated state. The thermal shock resistance of semi-recombined magnesia-chrome brick is better than that of direct-bonded magnesia chrome brick.
| Semi-rebonded magnesia chrome brick | BDMK-16 | BDMK-18 | BDMK-20 | BDMK-26 |
| MgO(%)≥ | 67 | 63 | 60 | 50 |
| Cr2O3(%)≥ | 16 | 18 | 20 | 26 |
| Density (g/cm3) | 3.00 | 3.10 | 3.15 | 3.15 |
| Porosity(%)≤ | 18 | 17 | 16 | 16 |
|
Thermal shock resistance
(Times under 1100 ºC) |
3 | 3 | 4 | 4 |