Characteristics of magnesia chrome bricks

Like magnesia chrome bricks, the main mineral composition of magnesia chrome bricks is spinel and periclase. It is also a composite alkaline refractory product made of sintered magnesia and chromite in proper proportion. The proportion of raw materials is not clearly specified. Generally, the ones with less than 50% of the addition amount of pyrite are called magnesia chrome bricks, and those with 50% or more are called chrome magnesia bricks. Its production process, performance characteristics and uses are basically similar

The synthetic raw material is the co sintering material made from the light burned material of relatively pure magnesite and chrome concentrate after fine grinding, mixing, compacting, and then calcining at high temperature;

The fused magnesia chrome material (also known as granulated magnesia chrome material) is made from magnesite and chrome ore by electric melting;

There are also fused magnesia, fused magnesia alumina spinel, etc. Synthetic materials are generally raw materials with low impurity content. Various kinds of magnesia chrome bricks can be made by using different combinations and formulas of the above materials.

It can be summarized as follows:

(1) Ordinary magnesia chrome bricks (i.e. silicate bonded magnesia chrome bricks). This kind of brick is made of magnesia and chromite. It contains a lot of impurities (CaO and SiO2), and its firing temperature is not high, about 1500 ℃. The microstructure of the brick is that the refractory grains are combined by silicate with lower melting point.

(2) Directly bonded magnesia chrome bricks. It is made of relatively pure magnesia and chrome concentrate, with low impurity content. The firing temperature of the brick is above 1700 ℃. The microstructure of the brick is that the refractory grains are mostly in direct contact with each other, so its high temperature performance, corrosion resistance and erosion resistance are better than ordinary magnesia chrome bricks.

(3) Co sintered magnesia chrome brick: the particles and fine powder of the brick are composed of synthetic co sintered magnesia chrome materials, with low impurity content, and are fired above 1750 ℃. The microstructure of bricks is also that the refractory particles are mostly in direct contact with each other; Its chemical composition and spinel distribution are uniform. Therefore, the erosion resistance and other properties of this brick are very good:

(4) Electric melting (molten particles) and then combining magnesia chrome bricks. The particles and fine powder of bricks are composed of fused magnesia chrome materials, which are fired at high temperature. This kind of brick has good wear resistance and erosion resistance, but its thermal shock resistance is not as good as co fired magnesia chrome brick.