Calcium carbonate content standard for lime kiln raw materials
The calcium carbonate content of lime kiln raw materials is a key factor affecting the quality and production efficiency of lime products. In lime kiln production, limestone is the main raw material, and its calcium carbonate content has clear and strict standards.
Generally speaking, the calcium carbonate content in limestone should reach a relatively high level. In most cases, it is required that the calcium carbonate content be above 90%, and a higher content is more beneficial for production. When the content of calcium carbonate is high, the production capacity of the lime kiln is large, the concentration of carbon dioxide in the kiln gas is high, and the concentration of ash milk is also high. The operation of the kiln is not easy to form lumps, and the rate of stone and sand return is low, resulting in low consumption of limestone.
From different application scenarios, in the field of calcium carbonate production, according to the national standard GB/T 3280-2015, the calcium carbonate content of limestone should be greater than or equal to 75%, which ensures the quality and efficiency of calcium carbonate production. In some specific lime kiln production standards, the requirements for calcium carbonate content are more stringent. For example, some require a calcium carbonate content of over 97% to ensure high calcium oxide content and good lime activity in the fired lime, which is conducive to improving the utilization rate and product quality of lime.
Impurities in limestone, such as silicon dioxide, magnesium oxide, aluminum oxide, and other oxides, will react with calcium carbonate during the firing process to form compounds that are not easily decomposed, reducing the purity of lime. Therefore, while ensuring the content of calcium carbonate, the impurity content should also be controlled to improve the purity and product quality of lime.
