Limestone is a kind of sedimentary rock, the main components are calcium carbonate and magnesium carbonate, etc. The tailings produced by sandstone processing are mainly stone chips and stone powder. Stone chips can generally replace fine aggregates and crushed stones as building foundation fillers, and can also be ground by a limestone mill and processed as resources at the same time as stone powder. Limestone powder can be used according to its physical and chemical properties, such as as an admixture for concrete, cement and PC components, and also as a high-calcium solvent for desulfurization in power plants and metallurgy. In addition to the construction industry, tailings from limestone sandstone mines have certain applications in the chemical, metallurgical, and even agricultural and pharmaceutical industries. Guilin Hongcheng, as a manufacturer of limestone mills, will introduce to you today the comprehensive utilization of limestone tailings for construction.
The comprehensive utilization of limestone tailings for construction, through the limestone grinding mill, can develop high-end products such as calcium carbonate, high-calcium powder for flux, and limestone powder for desulfurization in thermal power plants:
(1) Calcium carbonate: Light calcium carbonate is produced by calcining limestone and other raw materials to produce lime (the main component is calcium oxide) and carbon dioxide, and adding water to digest the lime to produce milk of lime (the main component is calcium hydroxide), and then carbon dioxide is added to carbonize Calcium carbonate precipitates from milk of lime, which is finally dehydrated, dried and crushed.
(2) Stone powder for desulfurization: At present, limestone desulfurization is the most important method for flue gas desulfurization in power plants because of its mature technology and stable operation. It provides a good market for tailing limestone powder to turn waste into treasure.
(3) High calcium powder for flux: High calcium limestone powder is widely used in the metallurgical industry. In black metallurgy, the role of high calcium powder is to convert gangue in iron ore, ash in fuel, and other harmful impurities into slag to eliminate, in order to facilitate the extraction of useful iron metals; During the steelmaking process, limestone discharges phosphorus and sulfur into the slag to improve the quality of the steel. In non-ferrous metal smelting, limestone serves as a reducing agent for oxidized ores and metals. With the changes in the iron ore resource market, the role of quicklime in strengthening sintering is gradually weakening. At the same time, the domestic steel market is declining, and major steel enterprises are facing enormous pressure, creating favorable conditions for optimizing the flux structure. For example, after adding limestone powder and dolomite powder to the raw solvent materials, Angang achieved relatively stable sinter quality and significantly reduced flux costs, achieving significant economic and social benefits; The addition of approximately 1.66% limestone powder to replace quicklime in sintering production at Jigang has shown no negative impact on the quality and economic indicators of sintered minerals, and can reduce the cost of flux and improve the stability rate of alkalinity. At present, high calcium stone powder has been widely used as a substitute for some quicklime in steel plants to reduce sintering costs. The main indicator requirement for high calcium stone powder used in flux is CaO (50 ± 2%), with a particle size of less than 3mm, and stone powder with a particle size ≤ 3mm must reach over 90%. Steelmaking requires the strictest quality of limestone, with good activity, stable composition, low impurity content (especially phosphorus and sulfur), and appropriate particle size.
As a manufacturer of limestone mills, Guilin Hongcheng produces Raymond mills, vertical mills, ultra-fine mills and other equipment, which have been widely used in comprehensive utilization projects of limestone tailings for construction, and can be applied to production Desulfurizer, calcium carbonate, lime powder and other products, the finished product fineness is 80-2500 mesh, if you have relevant needs, please leave us a message for details.