转底炉用含碳球团制备及生产工艺优化  

Preparation and production process optimization of carbon-bearing pellets for rotary bottom furnace

作　　者：杨涛 雷杰[1] 任晓健 万奇林[3] 周荣宝 龙红明 YANG Tao;LEI Jie;REN Xiao-jian;WAN Qi-lin;ZHOU Rong-bao;LONG Hong-ming(School of Metallurgical Engineering,Anhui University of Technology,Ma’anshan 243032,Anhui,China;Anhui Province Key Laboratory of Metallurgy Engineering and Resources Recycling,Anhui University of Technology,Ma’anshan 243002,Anhui,China;Resource Utilization Research Office,Jiangsu Yonggang Group Co.,Ltd.,Zhangjiagang 215628,Jiangsu,China)

机构地区：[1]安徽工业大学冶金工程学院,安徽马鞍山243032 [2]安徽工业大学冶金工程与资源综合利用安徽省重点实验室,安徽马鞍山243002 [3]江苏永钢集团有限公司资源利用研究室,江苏张家港215628

出　　处：《钢铁》2023年第4期157-166,共10页Iron and Steel

基　　金：安徽省自然科学基金杰青项目资助项目(2208085J19)。

摘　　要：转底炉直接还原工艺是目前处理含铁锌尘泥工艺的典型代表,能充分利用钢铁尘泥中的铁、碳和锌等物质,生产的金属化球团可返回炼铁/炼钢生产工序,同时可回收氧化锌粉等高附加值资源,成为钢铁企业含铁尘泥处理技术发展的趋势之一。基于某钢铁企业转底炉生产情况,从含碳球团的成型工艺参数及还原焙烧制度等方面进行分析与优化,以期为转底炉处理含铁尘泥工艺的推广和改进提供参考。揭示了压球工艺参数如水分、辊速和压力等对含碳球团的成球性及强度的影响规律,结果表明,3个参数相互作用、紧密相关,建议混合料压球水分、辊轮转速和辊轮压力分别控制为14%、6.0 r/min和2.5×10^(4)N/cm,此时原料的成球性能和球团强度等综合性能最佳;探究了焙烧温度、焙烧时间及摆放位置对金属化球团强度性能、金属化率及脱锌率的影响,结果表明,适当提高焙烧温度和延长焙烧时间使得金属铁连晶增加、渣相填充铁连晶间的孔隙,且金属铁相、浮氏体及渣相连结增强,可提高金属化球团的强度。其中焙烧温度对改善球团微观结构并提高球团抗压强度的作用最为显著,建议焙烧温度设定为1275℃、焙烧时间设定为25 min;摆放方式对还原后球团的平均抗压强度、金属化率和脱锌率等性能的影响较小,但3层摆放较2层摆放而言,会造成各层球团之间性能的差异逐渐增大。The rotary hearth furnace direct reduction is recognized as a typical process for the treatment of iron-and zinc-containing dust sludge,due to the full utilization of iron,carbon and zinc.The metallized pellets produced by the rotary hearth furnace are available for iron and steel production and high value added resources such as zinc oxide powder are recovered.The preparation process parameters and reduction roasting system of carbon-bearing pellets were analyzed and optimized based on the actual production conditions,contributing to the promotion and improvement of the process of treating iron-bearing dust sludge in the rotary hearth furnace.The effects of pelletizing process parameters such as moisture,roll speed and pressure on the sphericity and strength of carbon-bearing pellets were revealed.The optimal results were derived at 14%mix balling moisture,6.0 r/min roller speed and 2.5×10^(4) N/cm roller pressure.The effects of roasting temperature,roasting time and placement on the strength properties,metallization rate and dezincification rate of metallized pellets were investigated.Raising the roasting temperature and prolonging the roasting time appropriately resulted in an increase of metallic iron crystallization and a decrease of porosity.In addition,the metallic iron phase,faujasite and slag linkage were enhanced,leading to an improvement in the strength of the metallized pellets.The roasting temperature significantly affected the pellet microstructure and compressive strength.The optimal roasting temperature was 1275℃and roasting time was 25 min.The effect of placement on the properties of metallized pellets such as average compressive strength,metallization rate and dezincification rate was slight.However,the three-layer placement caused an increased difference in properties among the pellets compared to the two-layer placement.

关 键 词：冶金固废 含铁尘泥 转底炉 资源化 工艺优化 

分 类 号：TF046.6[冶金工程—冶金物理化学]