Application of Magnesium Iron Spinel Brick in Cement Kiln

The chromium-free measures in cement kilns are mainly to replace magnesia-chrome bricks with magnesia-dolomite brick, magnesia-alumina spinel brick, and magnesium iron spinel brick. The best refractory material to replace magnesia-chrome bricks in cement kilns.

Why use magnesium iron spinel bricks instead of magnesia chrome bricks?

Magnesia chrome bricks produce a public nuisance

A direct combination of magnesia-chrome bricks is a refractory material with good adaptability and high-cost performance for cement kilns. However, during use, the originally harmless Cr2O3 components in magnesia-chrome bricks combine with alkali components in kiln materials, which will form water-soluble toxic Cr 6+ compounds that form chromium pollution, which causes magnesia-chromium bricks to be eliminated by the cement industry. The direct combination of magnesia-chrome bricks is very suitable for the firing zone of a cement rotary kiln, mainly because magnesia-chrome bricks can form a protective kiln skin, and the formation of the kiln skin benefits from chromite, the raw material of magnesia-chrome bricks. The role of iron in the kiln skin is to participate in the formation of high-viscosity tetracalcium aluminate ferrite C, AF, and other kiln skin protective layers.

Magnesia spinel bricks are used in cement kilns

Introducing iron-aluminum spinel into magnesia refractory materials, the produced magnesia-iron-aluminum spinel brick provides a new furnace lining concept for cement rotary kilns. Its good structural flexibility and excellent kiln skin hanging performance make it Provides high adaptability. In recent years, magnesia-iron-aluminum spinel bricks have been fully used in the high-temperature zone of cement rotary kilns.

The characteristics of magnesia-iron composite spinel bricks

●During use, the hot surface of the brick forms a layer of highly viscous calcium-iron or calcium-aluminum-iron-oxide, which improves the performance of the kiln skin and the firmness of the kiln skin, and is suitable for protecting the lining bricks and extending their service life.
●The fused iron-aluminum spinel composite is added to the product, which not only has high strength but also has excellent thermal shock resistance. It can also effectively resist the chemical erosion of cement clinker liquid phase and alkali, sulfur, and other gases.
●The thermal expansion of spinel and periclase is inconsistent during the firing and cooling process. The micro-cracks formed between the two can buffer the stress impact caused by temperature changes and avoid the brittle explosion of the lining bricks.
●Chrome-free and environmentally friendly