Refractory Materials for Lime Kilns

Lime kilns are mainly divided into square kilns and round kilns. According to the classification of fired products, there are lime kilns and ceramic kilns. It is divided into a preheating zone, a firing zone, and a cooling zone.

The operating temperature of the preheating belt on the top of the lime kiln is not very high, but when firing products, the raw materials are easy to cause great wear and tear on the refractory bricks, and the furnace gas will cause serious chemical erosion of the refractory bricks. Therefore, attention must be paid to the strength, density, wear resistance, and corrosion resistance of refractory bricks.

Although the preheating zone does not have high-temperature requirements for refractory bricks, the other performance requirements for refractory bricks are very strict. Many factories use high alumina bricks and clay bricks, which are different.

Calcining area. The calcining zone is the area with the strongest chemical reaction of the refractory bricks used in lime kilns, and the calcining zone is also the stage with the highest temperature. So be careful when you have bricks. Has good thermal shock resistance, corrosion resistance, and wear resistance. Use dense high alumina bricks.

The calcining zone was initially constructed with dense high-alumina refractory bricks. However, in recent years, the use of alkaline refractory bricks has achieved better results, consistent with lime gas fields. Currently, due to cost reasons, there are many high-alumina bricks, but phosphate bricks and phosphate composite bricks are also useful. This depends on the usage habits and cost of each unit chosen.

However, it is not possible to use alkaline bricks in the firing zone. In areas close to the preheating and cooling zones, wear resistance is more important than corrosion resistance. Many manufacturers still use high-alumina refractory bricks with good wear resistance and high refractory temperature.

Then comes the cooling zone. Because when quicklime enters the cooling zone, there is still a lot of heat flowing back and forth in the cooling zone. Refractory bricks in the cooling zone should also be resistant to wear, rapid cooling and heating, and spalling. But when the diameter of the shaft kiln is small, many manufacturers also choose clay bricks.