It is widely used in the domestic hazardous waste disposal industry. Light burnt magnesia powder and the quality of the refractory materials of the rotary kiln affect the stable operation of the rotary kiln. The selection and maintenance of refractory materials for hazardous waste treatment rotary kilns are analyzed for reference for specific engineering applications. Hazardous wastes are corrosive, corrosive, flammable, reactive, infectious, and other hazardous properties defined in the National Hazardous Waste List. May cause harmful effects on the environment or human health, and need to be managed as hazardous waste. Among them, the thermal treatment (incineration) of hazardous waste can not completely eliminate the nature and hazard of the waste, and can reduce the volume of the hazardous waste, which is a powerful means to harmless and reduce the waste. At present, most of the newly-built hazardous waste incineration and disposal projects in China prefer the rotary kiln as the type of hazardous waste treatment furnace, which can effectively treat hazardous wastes of different shapes and phases. Light burnt magnesia powder

Rotary kiln-type incinerator, also known as rotary kiln, is a slightly inclined steel hollow cylinder lined with refractory bricks. Most of the waste materials are heated by the gas generated during the combustion process and the heat transmitted by the kiln wall. The solid waste is sent from the front end to the kiln for incineration, and it is rotated to achieve the purpose of mixing the waste. It is necessary to maintain a proper tilt when rotating to facilitate the solid waste to slide down. In addition, waste liquid and exhaust gas can be sent from the kiln head or the second combustion chamber, and even the whole barrel of waste can be sent to the rotary kiln incinerator for combustion.

Rotary kiln incineration technology is the mainstream technology in the current hazardous waste incineration technology. It is a furnace with many applications. Light-burned magnesia powder is a highly adaptable multi-purpose that can incinerate a variety of solid, semi-solid, liquid and gaseous wastes. In the incinerator, various combustible wastes of different types and shapes (granules, powders, blocks and barrels) can be sent to the rotary kiln for incineration.

Hazardous wastes are incinerated in rotary kilns, and generally go through several stages such as drying, pyrolysis, burning and burnout. After these stages, the harmful components in the hazardous waste are fully decomposed and destroyed under the action of high temperature, forming high-temperature flue gas and slag. These high temperature flue gas and slag will cause corrosive damage to the refractory materials built in the rotary kiln.

(1) Sex. It can run in a high temperature environment above 800 ℃ for a long time.

(2) And excellent sex. The refractory material in the rotary kiln needs to have the 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 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 thermal expansion stability is better. Although the thermal expansion coefficient of the rotary kiln shell is greater than the thermal expansion coefficient of the refractory material of the rotary kiln, the shell temperature is generally around 150-300 ℃, and the temperature of the refractory material is generally above 800 ℃, which may lead to the ratio of refractory materials. The thermal expansion of the rotary kiln shell is large, and it is easy to fall off.

(5) The porosity should be low. The high porosity makes the flue gas easy to penetrate into the refractory material and corrode the refractory material body.