Detailed performance of hot sale magnesia chrome bricks

Magnesia-chrome bricks are refractory products with magnesium oxide (MgO) and chromium trioxide (Cr2O3) as the main components, and perovskite and spinel as 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 acid slag. The main raw materials for manufacturing magnesia-chrome bricks are sintered magnesia and chromite. The purity of magnesia raw materials should be as high as possible. The chemical composition requirements of chromite are: Cr2O3: 30-45%, CaO: ≤1.0-1.5%.

 

The production process of fired magnesia-chrome bricks is roughly similar to magnesia bricks. In order to eliminate the loose effect caused by the expansion of MgO and Cr2O3, Al2O3 or iron oxide during the firing process to form spinel, synthetic co-sintering materials can also be used to make magnesia-chrome bricks. In addition, there are non-fired magnesia-chrome bricks, for example, non-fired magnesia-chromium bricks combined with an inorganic magnesium salt solution. The production process of non-fired magnesia-chrome bricks is simple, the cost is low, and the thermal stability is also good, but the high temperature strength is far less than that of fired bricks. At the end of the 1950s, a so-called "direct bonding" magnesia-chrome brick was developed. This kind of brick is characterized by pure raw materials, high firing temperature, direct combination between high-temperature phases such as brucite and spinel, and low-melting phases such as silicate are island-like distribution, therefore, the high temperature of the brick is significantly increased Strength and slag resistance.

The method of making bricks by using chrome ore-magnesia co-grinding and compacting calcined compacts and coarse magnesia particles is an effective measure to eliminate the loose effect. Compared with ordinary magnesia-chrome bricks, the magnesia-chrome bricks made by this method have lower porosity, higher compressive strength, load softening temperature and flexural strength. Magnesia-chrome bricks made of chrome ore-magnesite powder compacts and synthetic magnesite sand calcined at high temperature have better slag resistance and high temperature strength than other magnesia-chrome bricks.

 

In addition, there are fused cast magnesia chrome bricks obtained by direct casting of molten magnesia chromium material in an electric furnace, and fusible particles produced by the fused magnesia chromium material in accordance with the brick making process combined with magnesia chrome bricks.

 

Magnesia-chrome bricks are mainly used in the metallurgical industry, such as the construction of open hearth furnace roofs, electric furnace roofs, refining furnaces outside the furnace, and various non-ferrous metal smelting furnaces. The high-temperature part of the furnace wall of the ultra-high power electric furnace is made of fused cast magnesia chrome bricks, the high erosion zone of the outside refining furnace is made of synthetic materials, and the high erosion zone of the non-ferrous metal flash smelting furnace is made of molten cast magnesia chrome bricks and synthetic materials. Magnesia-chrome bricks. In addition, magnesia-chromium bricks are also used in cement rotary kiln firing zone and glass kiln regenerators.