Refractory bricks are mainly used for building smelting furnaces, and can be used as high-temperature building materials and structural materials for building kilns and various thermal equipment, and can withstand various physical and chemical changes and mechanical force at high temperatures. The performance and life of refractory bricks determine production efficiency, production quality and production safety. Therefore, how to effectively protect refractory bricks in the production process of kilns is a very important task.
This article answers how to effectively protect refractory bricks from several aspects that affect the safety of refractory bricks:
1. The influence of the physical properties of refractory bricks
Slag resistance refers to the ability of refractory materials to resist chemical corrosion. Slag resistance is very important when the initial layer of kiln skin is formed and when the material is viscous or local high temperature causes the kiln skin to fall off.
Porosity and thermal conductivity play an important role in the formation of the initial layer of kiln skin, and when the kiln skin is partially peeled off, refractory materials with larger porosity and thermal conductivity will help the kiln skin to be repaired in time. But at the same time, it may exhibit a great destructive effect, causing the thin layer of refractory bricks to fall off.
In the production process of refractory bricks, the physical and chemical changes generally have not reached the equilibrium state at the firing temperature. There are also refractory bricks that are not fully fired. Therefore, when they are subjected to high temperature in the rotary kiln, most refractory bricks undergo irreversible refiring shrinkage due to the generation of their own liquid phase and the filling of pores. Therefore, high-temperature volume stability must be considered when selecting fired-zone refractory bricks.
Next issue we will continue to introduce how to effectively protect refractory bricks during kiln’s production process.