Magnesia chrome brick

Magnesia-chrome bricks are refractory products containing magnesium oxide (MgO) and chromium oxide (Cr2O3) as the main components, and periclase and spinel are the main mineral components. This type of brick has high refractoriness, high temperature strength, strong resistance to alkaline slag, excellent thermal stability, and certain adaptability to acidic slag. The main raw materials for the manufacture of magnesia chrome bricks are sintered magnesia and chromite. The purity of the magnesia raw material of the magnesia brick manufacturer should be as high as possible. The requirements for the chemical composition of the chromite ore are: Cr2O3: 30-45%, CaO: ≤ 1.0-1.5%.

The production process of firing magnesia-chrome bricks is similar to that of magnesia bricks. In order to eliminate the brick during the firing process due to MgO and Cr2O3, Al2O3 or

The loosening effect caused by the expansion of iron oxides to form spinel can also be made into a magnesia chrome brick using a synthetic co-sintered material. In addition, there are non-calcined magnesia chrome bricks, for example, non-calcined magnesia chrome bricks combined with an inorganic magnesium salt solution. The non-burned magnesia chrome brick has a simple production process, low cost and good thermal stability, but the high temperature strength is far less than that of the fired brick. In the late 1950s, a so-called "direct combination" magnesia chrome brick was developed. The brick is characterized by pure raw materials, high firing temperature, direct combination of high temperature phases such as periclite and spinel, and low-melting phase such as silicate is island-shaped, thus significantly increasing the high temperature of the brick. Strength and slag resistance.

The method of preparing the fine powder prepared by calcining the calcined billet with chrome ore-magnesia sand and the coarse particles of magnesia is an effective measure for eliminating the loose effect. Compared with ordinary magnesia chrome bricks, the magnesia chrome bricks produced by this method have low porosity, high compressive strength, load softening temperature and flexural strength. Magnesia-chrome bricks made of chrome ore-magnesite powder compacts and high-temperature calcined synthetic magnesia-chrome sands are better than other magnesia-chrome bricks in slag resistance and high temperature strength.

In addition, there is a fused cast magnesia chrome brick obtained by directly casting a molten magnesia in an electric furnace (see the microscopic structure, see the color map), and the fused granules produced by the fused magnesia chrome material are combined with magnesium. Chrome bricks, etc.