What is magnesia chrome brick?

Magnesia-chrome brick is a kind of alkaline refractory product, Mgo contains: 55% -80%. Cr2O3 contains: 8% -20%, the main crystal phase is periclase and compound spinel XOY2O3, of which XO is mainly MgoFeO; Y2O3 is mainly Cr2O3.AI2O3.Fe2O3. XO is equal to the moles of Y2O3, and the excess Y2O3 is solid-dissolved in composite spinel. There is also a small amount of silicate (forsterite and calcium forsterite).

The raw materials of magnesia-chrome brick production are: natural raw materials, synthetic raw materials, industrial chromium oxide and industrial alumina. Natural raw materials: such as sintered magnesia at all levels, ordinary chrome ore and low impurity chrome concentrate. Synthetic raw materials: co-sintered magnesia-chromium materials in which magnesia and chromium concentrates are finely ground, mixed, compacted, and then calcined at high temperatures; and fused magnesia-chromium materials made from magnesite and chromium ore electrofusion; and Fused magnesia. Synthetic materials are generally low impurity raw materials.

 

Ordinary magnesia-chrome bricks are made of sintered magnesia (MGO contains 89%-92%) and refractory chrome bricks as the main raw materials, which are mixed, formed under high pressure, dried and fired at 1550-1600 degrees. Due to the high impurity content, the refractory particles are a combination of silicates, so the fired ordinary magnesia-chrome bricks are also called the combination of silicates and magnesia-chrome bricks, or magnesia-chrome bricks for short. The main raw materials for the manufacture of magnesia-chrome bricks are sintered magnesia and chromite. The purity of magnesia raw material should be as high as possible. The chemical composition requirements of chromite are: Cr2O3: 30~45%, CaO: <1.0~1.5%.

 

The characteristics of magnesia chrome bricks.

（1） high refractory temperature.

（2） 0.2MPA load softening temperature is high.

（3）Strong resistance to alkali slag.

（4） high temperature strength.

（5） Good volume stability at high temperature.

（6）The standard size is accurate, the construction is convenient, and it can be processed according to the drawings.

 

The usage of magnesia chrome brick:

Magnesia-chrome bricks are mainly used in the metallurgical industry, such as open-hearth furnace tops, electric furnace tops, out-of-furnace refining furnaces and various non-ferrous metal smelting furnaces. The high-temperature part of the ultra-high-power electric furnace wall adopts fused-cast magnesia-chrome bricks, the high-erosion area of the refining furnace outside the furnace adopts magnesia-chrome bricks made of synthetic materials, and the high-erosion areas of non-ferrous metal flash smelting furnaces use magnesia-chrome bricks which made of fused cast magnesia-chrome bricks and synthetic materials.In addition, magnesia-chrome bricks are also used in the firing zone of cement rotary kilns and the regenerators of glass kilns.

Zhengzhou Shennan Refractory Co.,Ltd are professional in producing magnesia chrome bricks, any demands,please don't hesitate contact with me. 


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