Selection points of refractory materials for rotary kiln

Hazardous waste is incinerated in a rotary kiln and generally undergoes several stages such as drying, pyrolysis, combustion, and burnout. After these stages, the harmful components in the hazardous waste are fully decomposed and destroyed under the action of high temperature to form high-temperature flue gas and slag. These high temperature flue gases and slag can cause erosive damage to the refractory materials built into the rotary kiln.

    Therefore, the refractory material of the rotary kiln for hazardous waste incineration should have the following characteristics:

    (1) High temperature resistance. It can operate in high temperature environment above 800 °C for a long time.

    (2) High strength and excellent wear resistance. The refractory material in the rotary kiln needs to have a certain mechanical strength to withstand the expansion stress at high temperature and the stress formed by the deformation of the rotary kiln shell.

    (3) Good chemical stability and thermal stability to resist the corrosion of chemical substances in the flue gas and to withstand the alternating thermal stress in the incineration state.

    (4) The stability of thermal expansion is better. Although the thermal expansion coefficient of the rotary kiln shell is larger than the thermal expansion coefficient of the rotary kiln refractory material, the shell temperature is generally around 150-300 °C, and the refractory material is generally subjected to temperatures above 800 °C, which may lead to refractory ratio. The thermal expansion of the rotary kiln shell is large and it is easy to fall off.

   (5) The porosity is low. A high porosity allows the flue gas to easily penetrate into the refractory material and corrode the refractory body.