The Research On High Quality Of Active Lime Roasted In Rotary Kiln

As an important auxiliary material for iron and steel industry, lime is an importantflux in the smelting process. Metallurgical active lime is mainly made from limestonethrough the lime kiln roasting, and activity is the main measure of its quality. With highactivity lime, not only the refining time can be reduced but also the effect ofdesulfurization and dephosphorization be improved during the smelting process. As aconsequence, the quality of pig iron and molten steel can be improved, raw materialscan be saved and the furnace can be improved. With the rapid development of the ironand steel industry the requirements for quality of metallurgical lime have exigent.Accordingly, It has been an important task that how to improve the quality of lime inmetallurgical production.The technological characteristics of active lime production at home and abroad wasanalyzed, of which rotary kiln is characterized by large production, simple processequipment and high quality product and accounts for a significant proportion inmetallurgical lime production. Besides, based on the investigation, the paper analysesrotary kiln system of XINYU IRON&STEEL GROUP CO.;LTD, in aspects of rawmaterials, equipment and technology. Also, we pointed out the existing problems in theproduction process and proposed several measures to procure rotary kiln more stabilityand promote improvement of the quality of the lime. We not only analyse calcinations mechanism, decomposition of thermodynamicsand thermodynamics of calcite, but also conduct study on the influence of raw materialparticle size, temperature, time and other factors on the quality of lime under laboratoryconditions. Results showed that the lime activity is the highest when the limestone ofwhich particle size is in about20to40mm has been calcined at1200°C for60min,and the maximum can reach398ml.Based on the above research, the industrial-scale tests of calcining technology foractivating lime were performed in the rotary kiln. The effects of raw materials, fuel,rotary equipment and thermal system on activity of lime were examined in theproduction practice, and the problems that exist in the production were improved. Afterthe improvement,the rotary kiln conditions becomes more stability, quality of lime is insmaller fluctuations, and the content of CaO reached93.10%and the mean activity islime more than385ml, meaning products have achieved high level in the country.