Experimental data on the optimal particle size range of limestone for burning lime
The particle size of limestone has a significant impact on the quality and production efficiency of lime calcination. Experimental data shows that there are differences in the optimal particle size range of limestone under different kiln types and calcination processes. When the traditional vertical kiln adopts a particle size of 50-100mm, the residence time inside the kiln is about 8-26 hours, and the production capacity significantly increases with the decrease of particle size. However, if the particle size is too small, it will lead to an increase in gas resistance. When the particle size drops to 30mm, the resistance per meter of kiln height reaches 1200Pa, which affects the uniformity of gas flow distribution inside the kiln.
The experiment of dual chamber parallel flow thermal storage lime kiln shows that when the particle size range is 30-60mm or 40-80mm, controlling the particle size ratio at 1:2 can optimize the porosity of the material layer and reduce the flow resistance of the furnace gas. The metallurgical industry has stricter requirements for the particle size of limestone, ensuring that the proportion of 40-80mm exceeds 80% and the particle size deviation does not exceed ± 10%. At the same time, it is required to have a regular appearance to reduce the generation of cracks during the calcination process.
The preparation experiment of high activity lime further confirms that ultrafine limestone with a particle size of 0.125-0.63mm can be calcined at 1000-1050 ℃ for 30-40 minutes to obtain products with fine grains and high porosity, significantly improving the activity. Based on various experimental data, the optimal particle size range of limestone needs to be determined comprehensively according to the kiln type, calcination temperature, and product requirements. Mechanical ventilation kilns are suitable for 50-100mm, and thermal storage kilns can be optimized to 30-80mm. However, the preparation of highly active lime requires the use of ultra-fine particle size control technology.
