Method of calcining high activity lime in lime kiln
Lime is an important material widely used in industries such as construction, steel, and chemical engineering. Highly active lime has become a popular product in the market due to its excellent reactivity and high application value. Lime kiln calcination is a key step in producing high activity lime. How to achieve the goal of calcining high activity lime in a lime kiln by optimizing raw material selection, calcination process, and equipment improvement.
1、 Raw material selection and pretreatment
The quality of raw materials has a crucial impact on the activity of lime. High purity and high CaCO3 content limestone are prerequisites for producing highly active lime. When selecting raw materials, it should be ensured that the chemical composition of limestone is stable and the impurity content is low.
The particle size of raw materials is also a key factor affecting the activity of lime. The particle size is too large, and the internal CaCO3 decomposition is incomplete, which affects the activity of lime; Particles that are too small are prone to overburning during calcination, which also leads to a decrease in lime activity. Therefore, it is recommended to control the particle size of the raw materials within the range of 15-40mm.
In addition, preheating the raw materials can accelerate the chemical reactions during the calcination process and improve the activity of lime. Preheating treatment can also reduce the heat consumption of lime kilns and improve energy utilization efficiency.
2、 Optimization of calcination process
The calcination temperature and time have a direct impact on the activity of lime. Excessive temperature can lead to overburning of lime and a decrease in activity; Low temperature leads to incomplete decomposition of CaCO3. The ideal calcination temperature range is 900-1200 ℃, and the specific temperature needs to be adjusted according to the characteristics of the raw materials.
Extending the calcination time is beneficial for the complete decomposition of CaCO3 and improving the activity of lime. However, prolonged calcination time can also lead to overburning of lime and a decrease in activity. Therefore, controlling the calcination time reasonably and ensuring the full decomposition of CaCO3 is the key to improving the activity of lime.
During the calcination process, an appropriate oxidizing atmosphere helps to improve the activity of lime. By controlling the air supply in the lime kiln and maintaining an appropriate oxidizing atmosphere, it is possible to avoid excessive burning of lime and improve its activity.
3、 Equipment improvement and automation control
Optimizing the structure of the lime kiln, such as using multi-stage calcination, can enable the raw materials to be calcined in stages at different temperatures, thereby improving the activity of lime. Meanwhile, optimizing the combustion system and adopting efficient combustion technologies such as oxygen enriched combustion can improve calcination efficiency and reduce the risk of lime overburning.
By using automated control systems such as PLC and DCS, key parameters such as calcination temperature, time, and atmosphere can be accurately controlled to ensure the stability of the calcination process and the uniformity of lime activity. Installing online monitoring systems, such as thermocouples and gas analyzers, can monitor key parameters such as temperature and atmosphere during the calcination process in real time, adjust the calcination process in a timely manner, and ensure the stability and uniformity of lime activity.
4、 Finished product quality inspection and continuous improvement
Establish a strict quality inspection system for finished products, regularly test the activity of lime to ensure product quality. Through comparative analysis, continuously optimize the calcination process and improve the activity of lime.
Improving the activity of lime calcined in lime kilns requires comprehensive measures from multiple aspects, such as raw material selection, calcination process optimization, equipment improvement, and quality control. Lime production enterprises should strengthen technology research and application, continuously optimize calcination processes, improve lime activity, and contribute to the high-quality development of the lime industry.
