What are the requirements for raw limestone in vertical lime kilns
The requirements for raw limestone in vertical lime kilns mainly include particle size distribution, impurity content, and chemical composition.
The particle size distribution of raw limestone has a significant impact on the firing efficiency of lime. Vertical lime kilns tend to choose limestone raw materials with uniform particle size and a size range of 40-80mm. This particle size of limestone can ensure the balance of filling density and airflow distribution in the shaft kiln, avoid the occurrence of "raw burning" and "over burning" phenomena, reduce dust generation, and simplify the waste gas treatment process.
The particle size of limestone, whether too large or too small, can affect the calcination effect. Larger particles can lead to a decrease in filling density and uneven airflow distribution, while smaller particles can easily generate dust, increasing the difficulty of waste gas treatment.
The impurity content of raw limestone has a direct impact on the quality of lime. Impurities such as silicon, aluminum, iron, magnesium and other oxides will react with calcium carbonate during the firing process to form compounds that are not easily decomposed, reducing the purity and activity of lime. Therefore, selecting limestone raw materials with low impurity content is the key to improving the quality of lime.
The chemical composition of raw limestone, especially the content of calcium carbonate, also has a significant impact on the firing rate and product quality of lime. Limestone raw materials with high calcium carbonate content can accelerate the burning speed of lime, increase the activity of lime, and thus improve product quality
In actual production, controlling the calcination temperature and time of limestone is also an important measure to ensure the quality of lime.
