Does a lime kiln need to use alkaline or acidic refractory materials?
Lime kilns usually require the use of alkaline refractory materials. A lime kiln is an equipment used to produce lime, and the production process of lime involves high-temperature reactions. In such a high temperature environment, alkaline refractory materials are usually more resistant to high temperatures and can resist the erosion of alkaline substances produced during the lime manufacturing process.
Generally, refractory materials are divided into three types: alkaline, acidic and neutral, and which one to choose depends on the process conditions and the chemical properties of the material. In the case of lime kilns, alkaline refractory materials are more suitable because the lime manufacturing process produces alkaline exhaust gases and alkaline substances, and alkaline refractory materials can better resist these erosions.
The kiln type of lime kiln is commonly used in the building materials industry. The choice of refractory bricks is different from that of cement kilns. There are phosphate bricks, high-load soft bricks, magnesia bricks, and magnesia-aluminum spinels brick.
The calcined belt lining of the lime kiln is damaged quickly by the abrasion of materials, air flow erosion and chemical erosion of CaO at high temperatures. For small and medium-sized vertical kilns, high alumina bricks and sillimanite bricks with low porosity are generally used; for large vertical kilns, alkaline bricks such as magnesia bricks, magnesia bricks, and magnesia spinel bricks are mostly used as the firing belt lining.
The cooling zone of the lime shaft kiln and the lining around the discharge port are also used at relatively low temperatures. The damage is caused by the wear of the lime and the temperature difference caused by the alternating action of hot and cold. High-strength clay bricks can be used for this part. The following table shows the refractory materials used in lime shaft kilns.
It should be noted that the specific choice may also depend on the specific design and operating conditions of the lime kiln, so it is recommended to seek advice from an engineer or someone working in the relevant industry when selecting refractory materials.
