论文部分内容阅读
印度JSW钢铁公司是一家年产钢700万t的联合钢铁企业,其炼铁单元由2座COREX和3座高炉组成。COREX和高炉用球团由一个年产420万t的带式焙烧机球团厂供给。作为一项重要的冶金性能指标,球团的还原粉化指数(RDI)要求满足COREX和高炉冶炼的要求。通过建立神经元网络模型和敏感度分析,研究了给料率、料层高度、焙烧温度、干透点温度、COREX煤气单耗、膨润土的添加量、生球水分、生球碳含量、以及成品球的MgO、Al2O3含量和碱度等12个因素对球团RDI指标的影响,并对焙烧机生产球团的RDI(-6.3mm)和RDI(-0.5mm)进行了预测。结果表明,球团中MgO、CaO/SiO2,生球碳含量和Al2O3含量对球团RDI指标影响较大。预测结果与实际的数据误差低于4%。研究得出:①生球的MgO、氧化铝和碳含量以及二元碱度对球团RDI有重要影响。②随着球团MgO含量和球团二元碱度的升高,球团RDI(-6.3mm)和RDI(-0.5mm)得到改善。③随着生球中氧化铝含量的增加,球团RDI升高,因此应尽量使用低氧化铝含量的铁矿粉来降低球团中的氧化铝。随着生球中氧化铝和碳含量的增加,球团RDI(-6.3mm)和RDI(-0.5mm)有所降低。④提高球团二元碱度和MgO含量的同时,降低生球碳含量可以改善球团的RDI。因此需要对它们的配比进行优化。⑤二元碱度0.50～0.55,MgO质量分数0.35%～0.45%,生球碳质量分数1.15%～1.20%,焙烧球氧化铝质量分数低于2.5%,FeO质量分数低于0.60%时,可望得到较低的RDI。⑥相对于球团中的碳和CaO含量,最优的焙烧温度可以改善球团的RDI(-6.3mm)和RDI(-0.5mm)。⑦高给料率和较高的料层高度会使球团的RDI(-6.3mm)和RDI(-0.5mm)升高。
India JSW Steel is a joint-stock steel company that produces 7 million tons of steel a year. Its ironmaking unit consists of two COREX and three blast furnaces. COREX and blast furnace pellets are supplied by a belt roaster pellet plant with an annual output of 4.2 million t. As an important metallurgical performance index, pellets’ reduction pulverization index (RDI) is required to meet the requirements of COREX and blast furnace smelting. Through the establishment of neural network model and sensitivity analysis, the feeding rate, material height, baking temperature, dry-point temperature, COREX gas consumption, the amount of bentonite, green ball moisture content, MgO, Al 2 O 3 content and alkalinity were investigated. The RDI (-6.3mm) and RDI (-0.5mm) of the pellets produced by roaster were predicted. The results show that the pellets in the MgO, CaO / SiO2, green ball carbon content and Al2O3 content of the pellet RDI greater impact. The prediction error is less than 4% from the actual data. The results show that: ① raw ball of MgO, alumina and carbon content and binary alkalinity have an important impact on pellet RDI. (2) The RDI (-6.3mm) and RDI (-0.5mm) were improved with the increase of pellet MgO content and pellet binary basicity. (3) With the increase of the alumina content in the green ball, the RDI of the pellets will increase. Therefore, the iron oxide powder with low alumina content should be used to reduce the alumina in the pellet. With increasing alumina and carbon content in the pellets, the pellet RDI (-6.3 mm) and RDI (-0.5 mm) decreased. ④ improve the pellet binary basicity and MgO content, while reducing the green ball carbon content can improve pellet RDI. Therefore need to optimize their ratio. ⑤ binary basicity of 0.50 ~ 0.55, MgO mass fraction of 0.35% to 0.45%, the ball of carbon mass fraction of 1.15% ~ 1.20%, roasting ball alumina mass fraction of less than 2.5%, FeO mass fraction of less than 0.60% Hope to get a lower RDI. ⑥ The optimal calcination temperature can improve the pellet’s RDI (-6.3mm) and RDI (-0.5mm) relative to the carbon and CaO content of pellets. ⑦ High feed rates and higher bed height result in higher pellet RDI (-6.3 mm) and RDI (-0.5 mm).