What are the differences in alkali resistance of different refractory brick series?

The alkali resistance of refractory bricks is the key performance of resisting the erosion of alkaline slag in high-temperature environments. Refractory bricks of different materials have significantly different alkali resistance performance due to differences in composition and structure.
There are many types of refractory brick series: silicon-aluminum series, magnesium series, calcium aluminate series, composite material series, aluminum-carbon series, magnesium-aluminum spinel series, and different series have different alkali resistance.

Silicon-alumina series refractory bricks

Silicon-alumina series refractory bricks are the least resistant to alkaline corrosion. High-alumina bricks, clay bricks, そして ムライトレンガ are severely damaged and expanded, and have the worst resistance to alkali metal corrosion. High-alumina bricks and mullite bricks cannot be used in kilns in alkaline atmospheres because silicon-alumina bricks have no alkali resistance under high alkali corrosion.

Magnesia series refractory bricks

The refractory bricks of the magnesia series not only have high refractoriness, 優れた耐熱衝撃性, and strong alkali resistance. 現在のところ, the alkaline atmosphere of cement rotary kilns uses magnesia series products as lining.

Magnesia-alumina spinel refractory brick series

The refractory bricks of the magnesia-alumina spinel series have a stable structure and are resistant to corrosion. Magnesia-alumina spinel refractory bricks have a high melting point, low thermal conductivity, small thermal expansion, high strength and hardness, strong impact resistance and alkali corrosion resistance, and are also very stable against iron oxides. It is the most selected refractory brick variety for furnace linings with strong alkaline corrosion.

Composite refractory bricks

Composite refractory bricks also have good resistance to alkali corrosion, such as silicon carbide combined with corundum bricks and silicon nitride combined with refractory bricks. Composite refractory bricks have good thermal shock stability, erosion resistance, wear resistance, and good resistance to slag erosion.

Aluminum carbon series refractory bricks

Aluminum-carbon series refractory bricks are widely used in blast furnaces. Alkali-corroded hot metal pretreatment furnaces and molten reduction furnaces all use this product. The corundum particles react with ferrous oxide, sodium oxide, and potassium oxide in the ash to form ferroaluminum spinel. This refractory brick will slow down the alkali corrosion process, but at the same time,e it will adhere to refractory materials and ash to form nepheline and low-temperature eutectic, resulting in matrix embrittlement damage.