In the production process of calcined zinc oxide, controlling energy consumption and emissions is the key to ensuring the dual goals of production efficiency and environmental protection.
Calcination temperature and time are important factors affecting the calcination effect of zinc oxide. Reasonable calcination parameters can significantly reduce energy consumption. By determining the optimal calcination temperature and time through experiments, unnecessary energy waste can be reduced while ensuring product quality. For example, a company reduced the calcination temperature from 1250℃ to 1150℃, the zinc recovery rate remained above 92%, and fuel consumption was reduced by 12%. This optimization not only improves energy utilization efficiency, but also reduces production costs.
The design of the kiln structure has a direct impact on energy consumption and emissions. The use of double-layer refractory bricks plus ceramic fiber composite insulation layer can effectively reduce the surface temperature of the kiln and reduce heat loss. At the same time, the installation of a hydraulic wheel stop device can reduce the deviation of the kiln, reduce the motor load, and further save energy. These structural improvements not only improve the thermal efficiency of the kiln, but also extend the service life of the equipment.
The high-temperature exhaust gas generated during the calcined zinc oxide process is a valuable thermal energy resource. High-temperature waste gas (above 500℃) is converted into steam through waste heat boilers, which can be used for raw material drying or power generation; low-temperature waste gas (<200℃) can be used for plant heating. This way of cascade utilization of waste heat not only reduces energy waste, but also reduces dependence on external energy.
Intelligent control of the calcination process can be achieved by installing online monitoring instruments for kiln tail temperature and oxygen concentration, and adjusting the blower speed and fuel supply in a linked manner. The intelligent control system can automatically adjust the calcination parameters according to the actual production situation to ensure the stability and efficiency of the production process. At the same time, it can also detect and handle abnormal situations in a timely manner to reduce energy consumption and emission risks.
Pretreatment of raw materials is crucial for energy consumption and emission control during calcination. Through pretreatment steps such as crushing, screening, and drying, the uniformity and reactivity of raw materials can be improved, and the calcination time and energy consumption can be reduced. In addition, the use of industrial solid wastes such as red mud and steel slag as alternative fuels or raw materials can be explored, which not only reduces the cost of raw materials, but also reduces the use of fossil energy and waste emissions.
The waste gas generated during the calcined zinc oxide process contains acidic substances such as sulfides, which need to be desulfurized before they can be discharged. The use of advanced desulfurization technology and equipment, such as desulfurization towers, can effectively remove harmful substances in the waste gas and ensure that emissions meet standards. At the same time, it can also optimize the kiln head seal and negative pressure control, balance the contradiction between environmental protection and energy consumption, and reduce unnecessary energy consumption and emissions.
Establish an energy ledger, count the energy consumption data of electricity, coal, water, etc. by shift, and set up a red, yellow, and green light warning mechanism for energy consumption per ton of product, so that energy consumption anomalies can be discovered in time and measures can be taken to improve them. In addition, regular energy-saving training is conducted for operators to correct bad operating habits and improve employees' energy-saving awareness and operating skills. Cooperating with scientific research institutions to develop new technologies and processes, such as hydrogen as auxiliary fuel, microwave heating combined with rotary kilns, etc., is also an effective way to reduce energy consumption and emissions.
By optimizing calcination parameters, upgrading kiln structure, cascade utilization of waste heat, intelligent control system, raw material pretreatment and substitution, waste gas treatment and emission control, as well as energy management and continuous improvement, energy consumption and emissions can be effectively controlled in the production process of calcined zinc oxide, achieving a win-win situation of economic benefits and environmental protection.
