摘要
带式焙烧机是单机大型化球团生产工艺之一,高压辊磨、强力混匀等原料预处理工艺的合理搭配是拓展原料适应性、减少膨润土消耗、改善球团质量的有效手段。针对某钢铁企业带式焙烧机原料预处理流程中辊磨压力过剩和原料处理系数较低等问题,开展了高压辊磨、强力混合联接的工业试验,揭示了辊压强度、上料量等工艺参数对球团的成球性及强度的影响规律,为球团生产的提质降耗提供理论指导。结果表明,辊磨机的上料量与辊压大小对原料粒度和比表面积均有影响,随着上料量减少或辊压提高,原料粒度变细,比表面积增加。在上料量为500 t/h、辊压为90 MPa时,混合料中粒度小于44μm所占比例由辊磨前的72.20%上升至83.94%,粒度小于74μm比例由辊磨前的89.96%上升至95.82%;经过强力混合后,原料中0.044 mm和0.074 mm粒级的比例基本不变,但是粒度分布更加均衡;膨润土和水结合后毛细水和分子水均有较大幅度的提升,所提供的分子力使大颗粒表面黏附较多细微颗粒物,比表面积由辊磨前的922.88 cm^(2)/g增加至1411.15 cm^(2)/g,成球性能得到改善。预处理原料应用于生产时,生球落下强度为5.0~7.0次/(0.5 m),同时,膨润土消耗降低2~3 kg/t,铁品位提高0.05%~0.16%,显著改善了带式焙烧机球团原料质量与生产效率。
Belt roasting machine is one of the production processes of single-large-scale pellet.The reasonable collocation of raw material pretreatment processes such as high pressure grinding rolls and strong mixing is an effective means to expand the adaptability of raw materials,reduce bentonite consumption and improve the quality of pellets.In response to the problems of excessive roller mill pressure and low raw material handling coefficient in the raw material pretreatment process of belt roasting machine in an iron and steel enterprise,the industrial tests of high-pressure roller mill coupling with powerful mixing were carried out to reveal the influence law of process parameters such as roller pressure strength and feeding volume on the sphericity and strength of pellets to provide theoretical guidance for improving quality and reducing consumption in pelletizing.The results showed that the feeding quantity and pressure of the roller mill had an effect on the particle size and specific surface area of raw materials.With the reduction of the feeding quantity or the increase of the roller pressure,the particle size of raw materials was finer and the specific surface area were lager.When the loading volume was 500 t/h and the roll pressure was 90 MPa,the proportion of the mixture with a particle size less than 44μm increased from 72.20% before roller grinding to 83.94%,and the proportion of particle size less than 74μm increased from 89.96% before roller grinding to 95.82%.After strong mixing,the proportion of 0.044 mm和0.074 mm particle size was basically unchanged,but the particle size distribution was more balanced.After the combination of bentonite and water,the lager molecular force provided by the capillary water and molecular water were substantially increased,resulted that the surface of large particles adhere to more fine particles.The specific surface area increased from 922.88 cm^(2)/g before roller grinding to 1411.15 cm^(2)/g,and the sphere-forming performance was improved.When the pretreated raw material was applied to production,the green pellet falling strength was 5.0-7.0 times/(0.5 m).Meanwhile,the bentonite consumption was reduced by 2-3 kg/t and the iron grade was increased by 0.05%-0.16%,which significantly improved the quality and production efficiency of pellet in belt roasting machine.
作者
刘山平
马磊
宋云锋
过刚
雷杰
龙红明
LIU Shanping;MA Lei;SONG Yunfeng;GUO Gang;LEI Jie;LONG Hongming(Manufacturing Department,Maanshan Iron and Steel Group,Maanshan 243032,Anhui,China;School of Metallurgical Engineering,Anhui University of Technology,Maanshan 243032,Anhui,China;Key Laboratory of Metallurgical Engineering and Resource Utilization in Anhui Province,Anhui University of Technology,Maanshan 243032,Anhui,China)
出处
《钢铁》
CAS
CSCD
北大核心
2023年第6期36-44,共9页
Iron and Steel
基金
安徽省自然科学基金杰青资助项目(2208085J19)
国家自然科学基金面上资助项目(52174290)。
关键词
带式焙烧机
生球质量
高压辊磨
强力混合
工艺优化
belt roaster
green pellet quality
high pressure roller grinding
strong mixing
process optimization
