Semi-rebonded magnesia chrome brick for Metallurgical industry

Semi-recombined magnesia-chrome bricks refer to refractory products fired from partially fused magnesia-chrome sand. The main mineral composition of semi-recombined 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 combination. Magnesia chrome brick.

Manufacturing process

The fused magnesia-chromium material is used as granules, and some chrome ore and magnesia are added or sintered to synthesize magnesia-chromium material as fine powder, and bricks are made according to the conventional process. The fused magnesia name material should be smelted in a weak oxidizing atmosphere, and there should not be a lot of reducing phase in the material, and metal iron and chromium should not be avoided; magnesia and chromite used as fine powder must be ground together, and the fineness should be guaranteed. Less than 0.088mm accounts for more than 95%; using a high-tonnage brick press to form, the brick density is greater than 3.2g/cm3. After the bricks are dried, the moisture content of the kiln is less than 1.0%. The products are fired in a tunnel kiln, the firing temperature is above 1750°C, and a weak oxidizing atmosphere is maintained in the kiln

Characteristic

Semi-recombined magnesia-chrome bricks are dense, low porosity, high temperature strength, better thermal shock resistance than recombined magnesia-chrome bricks, and have strong slag erosion resistance. It can be used in vulnerable parts of steelmaking electric furnaces, RH, DH vacuum degassing devices, secondary refining slag lines such as VOD, LF, ASEA-SKF, AOD and other severely eroded parts, copper smelting converter tuyere area, cement rotary kiln firing zone and glass furnace regenerator.

Application

Semi-recombined magnesia-chrome bricks have lower cost and better thermal shock resistance than recombined magnesia-chrome bricks with similar compositions, and can replace recombined magnesia-chrome bricks within a certain range.