Kiln coating adherence refers to the ability of refractory materials in a cement rotary kiln to react with cement during operation, forming a protective layer on the surface of the refractory lining. This ability is known as kiln coating adherence. This is the key point of choosing refractory castables of the kiln lining refractory materials.
A suitable kiln coating can protect the refractory material, prevent further erosion, and provide a certain degree of thermal insulation, thereby reducing heat loss. Therefore, kiln coating adherence is one of the important properties of refractory materials in cement rotary kilns.
How to Form Kiln Coating Adherence in a Cement Rotary Kiln Lining?
Kiln coating adherence is crucial for protecting refractory materials and ensuring the efficiency of cement rotary kiln operation.
To form and maintain a stable kiln coating, consider the following factors:
1. Control of Operating Parameters:
- Maintain an appropriate kiln temperature (1400-1500°C) to facilitate proper clinker formation and bonding of the coating.
- Avoid excessive fluctuations in feed composition and kiln speed, as these can cause coating instability.
- Optimize the burning zone atmosphere to avoid excess oxidation or reduction, which can weaken coating formation.
2. Proper Selection of Raw Materials:
- The composition of raw materials, especially the ratio of lime (CaO), silica (SiO₂), alumina (Al₂O₃), and iron oxide (Fe₂O₃), influences coating adherence.
- High liquid phase formation in the burning zone helps in coating buildup.
3. Coating Formation Process:
- A sufficient liquid phase (formed by clinker minerals like C₃A and C₄AF) promotes adhesion to the refractory surface.
- A slow and gradual heating process during kiln startup helps in forming a protective coating layer.
- A rough refractory surface provides a better base for coating attachment.
