輕燒鎂粉的選用及維護技術 Selection and maintenance technology of light burned magnesium powder
發布日期：2019-03-11 00:00 來源：http://www.hakatayanoodle.com 點擊：
It is widely used in domestic hazardous waste disposal industry. The quality of the refractories of the rotary kiln affects the stable operation of the rotary kiln. The light-burned magnesium balls were analyzed for the selection and maintenance of refractory materials for the rotary kiln for hazardous waste treatment for reference in specific engineering applications. Hazardous waste has corrosive, toxic, flammable, reactive, infectious and other hazardous properties according to the definition of the National Hazardous Waste List. It may cause harmful effects to the environment or human health, and needs to be managed as hazardous waste. Among them, the method of heat treatment (incineration) of hazardous waste can not only completely eliminate the toxicity and hazards of the waste, but also can reduce the volume of the hazardous waste to the greatest extent. It is the most powerful means for the harmlessness and reduction of waste. At present, most newly built hazardous waste incineration treatment projects in China use rotary kiln as a hazardous waste treatment furnace type, which can effectively treat different shapes and phases of hazardous waste.
Rotary kiln incinerator, also called rotary kiln, is a slightly inclined steel hollow cylinder lined with refractory bricks. Most 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 to the kiln from the front end for incineration, and it is rotated to achieve the purpose of stirring the waste. The rotation must be kept at an appropriate tilt to facilitate the sliding of solid waste. In addition, waste liquid and waste 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 currently the most mainstream technology in hazardous waste incineration technology. It is the most widely used furnace type. Light-burned magnesium powder is a highly adaptable and can incinerate a variety of solid, semi-solid, liquid, and gas wastes. Use incinerators, various types and shapes (particles, powders, blocks and barrels) of combustible waste can be sent to a rotary kiln for incineration.
(1)耐高溫性。能夠長期在 800 ℃以上的高溫環境下運行。
(4)受熱膨脹穩定性要好。 回轉窯殼體的熱膨脹系數雖然大于回轉窯耐火材料的熱膨脹系數，但是殼體溫度一般都在150～300 ℃左右，而耐火材料承受的溫度一般都在 800 ℃以上，這樣可能會導致耐火材料比回轉窯殼體的熱膨脹要大，而容易脫落。
Hazardous waste is incinerated in a rotary kiln, which 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, forming high temperature flue gas and slag. These high temperature flue gases and slag can cause erosive damage to the refractory materials built in the rotary kiln.
(1) High temperature resistance. Able to run in high temperature environment above 800 ℃ for a long time.
(2) High strength and excellent abrasion 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 caused 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 incinerated 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 of the rotary kiln, the shell temperature is generally around 150-300 ℃, and the temperature of the refractory is generally above 800 ℃, which may cause the refractory ratio The thermal expansion of the rotary kiln shell is large, and it is easy to fall off.
(5) The porosity should be low. High porosity will make the flue gas easily penetrate into the refractory material and corrode the refractory body.