Requirements for raw limestone in vertical lime kilns
As the core equipment for lime production, the production efficiency and lime quality of a vertical lime kiln are directly affected by the raw material limestone. The quality of raw limestone, especially particle size and calcium content, plays a crucial role in the operational efficiency of lime kilns and the quality of final products.
1、 Requirements for particle size of raw limestone
Particle size range: For vertical lime kilns, the particle size of raw limestone is generally required to be between 40-80mm. The setting of this size range aims to balance heat transfer efficiency and material fluidity.
Heat transfer efficiency: If the particle size is too small, although it can increase the heat transfer area, it is easy to cause material blockage in the kiln, affecting the flow of hot air and reducing heat transfer efficiency. If the particles are too large, the heat transfer path will become longer, which may lead to insufficient internal decomposition.
Material flowability: Appropriate particle size can ensure smooth flow of materials in the vertical kiln, avoiding material accumulation or poor flow caused by particles that are too large or too small, which affects production continuity and efficiency.
2、 Requirements for calcium content in raw limestone
Calcium content standard: The calcium content (CaCO3 content) of raw limestone is one of the key factors determining the final quality of lime, generally required to be above 50%. Limestone with high calcium content can improve the purity and activity of lime, and reduce production costs.
Lime quality: Limestone with high calcium content decomposes during the calcination process to produce lime (CaO) with high purity and good activity, which is suitable for various industrial applications such as steel smelting, chemical production, sewage treatment, etc. Production cost: Limestone with high calcium content can reduce the decomposition consumption of non calcium components during the calcination process, lower fuel demand, and thus reduce production costs.
3、 Quality control of raw limestone
Raw material screening: By using screening equipment, ensure that the particle size of the raw limestone meets the requirements, avoiding particles that are too large or too small from entering the vertical kiln and affecting production efficiency.
Chemical analysis: Conduct chemical composition analysis on raw limestone to ensure that the calcium content meets the standard. If necessary, adjust the calcium content by mixing limestone of different qualities to meet production needs.
Raw material pretreatment: For limestone with low calcium content, pretreatment processes such as flotation, magnetic separation, etc. can be used to increase its calcium content to meet the requirements of vertical kiln production.
The vertical kiln of lime kiln has strict requirements for the quality of raw limestone, especially the control of particle size and calcium content, which has a direct impact on production efficiency and lime quality. Through scientific raw material screening, chemical analysis, and pretreatment, it is possible to ensure that the raw limestone meets the requirements of vertical kiln production, improve the operational efficiency of the lime kiln and the quality of the final product, and provide a solid foundation for the development of the lime industry. Lime production enterprises should strengthen the quality management of raw limestone, adopt advanced technology and equipment, ensure the quality of raw limestone, and achieve efficient, high-quality, and low-cost lime production.
