Cement rotary kiln belongs to the category of building materials equipment and is a type of lime kiln. Rotary kilns can be divided into cement rotary kilns, metallurgical and chemical rotary kilns, and lime rotary kilns depending on the materials being processed. Cement rotary kiln is the main equipment for dry and wet cement clinker production lines.
First, we need to understand what hazardous waste is. According to regulations, hazardous waste refers to waste that has one or several hazardous characteristics such as corrosivity, toxicity, flammability, reactivity, or infectivity. It also refers to waste that has hazardous characteristics and may have harmful effects on the environment or human health. Knowing this, you may realize that hazardous waste is actually all around us. The wide range of sources and large quantities of hazardous waste have been a cause for concern. The harm of hazardous waste to human health and the damage it causes to the ecological environment have been taken seriously by countries around the world. Some even refer to hazardous waste as political waste, indicating the troubles it brings to people's lives. Therefore, it is of utmost importance to improve the treatment and recycling of hazardous waste in order to build a green, low-carbon, environmentally friendly, and energy-saving lifestyle and work.
After long-term exploration and experimentation, many methods have been developed to handle hazardous waste, such as landfilling, incineration, and using chemical or physical methods for neutralization, extraction, magnetic separation, hydrolysis, and precipitation, among others. Among them, the use of cement rotary kiln technology to treat hazardous waste has become the most effective method for its unique advantages, and it has been widely promoted and applied.
Cement rotary kilns have high incineration temperature and stable operation, which ensures more thorough combustion of waste. When the rotary kiln is running, it operates under negative pressure, avoiding the overflow of harmful gases during the treatment of hazardous waste. Additionally, due to the good sealing of the rotary kiln, it does not cause dust pollution, which is beneficial for environmental protection. The chlorine, sulfur, fluorine, and other chemical components contained in hazardous waste are completely absorbed and transformed into non-toxic calcium chloride, calcium sulfate, calcium fluoride, etc., during high-temperature treatment. They directly mix with cement clinker. It has been verified that they generally do not have adverse effects on the quality of cement. The waste generated during incineration produces a certain amount of heat, which saves the consumption of coal and reduces production costs.
Cement rotary kiln has the advantages of environmental protection, energy saving, safety, and certain economic benefits in the treatment of hazardous waste.
In addition to calcining cement clinker, cement rotary kiln is also used for calcining clay, limestone, and drying slag in the production of refractory materials. In non-ferrous and ferrous metallurgy, metals such as iron, aluminum, copper, zinc, tin, nickel, tungsten, and chromium are processed using rotary kilns as smelting equipment for sintering and roasting ores, concentrates, and intermediates. In the beneficiation process, rotary kilns are used for magnetizing roasting of low-grade iron ore, transforming its weak magnetism into strong magnetism, facilitating magnetic separation. In the chemical industry, rotary kilns are used for soda production, calcining phosphorus fertilizer, barium sulfide, and more. This method has the advantages of low energy consumption, low power consumption, no use of sulfuric acid, and the ability to utilize medium and low-grade phosphate ore, making it quickly popularized.
Furthermore, in terms of environmental protection, cement kilns can be used to incinerate hazardous waste and garbage, which not only reduces waste and renders it harmless but also utilizes waste as fuel, saving coal powder and achieving the resource utilization of waste.