基于高炉炉料结构优化的源头减排技术及应用

Application practice of source and process sulfur-nitrate reduction technology based on optimization of blast furnace charge structure

为了更进一步降低污染物排放总量,河钢集团在实现污染物超低排放的同时积极开展源头和过程硫硝减排技术研发。针对国内矿粉资源特点和球团、烧结过程污染物生成规律,以减少污染物生成总量为出发点,开发出适于高比例球团冶炼的低排放、低能耗熔剂性球团制备技术,阐明了熔剂性球团焙烧过程吸放热规律,克服了生球爆裂、回转窑结圈等技术难题,成功生产出SiO2质量分数在4.5%以上,MgO质量分数为1.8%左右,二元碱度(R2)为1.0左右的镁质熔剂性球团,并且具备长期连续生产的能力。开发了焙烧温度与球团矿质量调控、燃烧温度与硫硝生成控制技术,使得熔剂性球团抗压强度大于2 200N/个,SO2生成量比酸性球团降低了20%,比烧结矿产生的SO2、NOx分别降低75%、53%。研发了高比例球团高炉冶炼集成技术,高炉球团质量分数由20%增加到80%,燃料比降低11kg/t,吨铁SO2、NOx分别减排50%、26%。提出了炼铁流程全生命周期节能减排定量分析方法和持续改进方向,成功实现污染物在源头和过程上的削减。已成功推广至河钢集团2 000m^3级、3 000m^3级高炉和河钢乐亭沿海基地3 000m^3级高炉在建项目上,为国内钢铁工业减少污染物排放总量开辟了新的方向。

On the premise of achieving ultra-low pollutant emission,HBIS actively carries out research and development of source and process sulfur-nitrate emission reduction technology in order to further reduce the total pollutant emission.Aiming at the characteristics of domestic mineral powder resources and the law of pollutant generation in pellets and sintering process,the fluxed pellet with low-emission and low-energy,which is suitable for high ratio pellet smelting,was developed to reduce the total pollutant emission.The heat absorption and release law of fluxed pellet during the roasting process was clarified,the technical problems such as green ball bursting and rotary kiln ring formation were overcame,the magnesium fluxed pellet with mass percent of SiO2 above 4.5%,mass percent of MgO about 1.8%,and binary alkalinity(R2)around 1.0 was developed with long-term continuous production.The roasting temperature and pellet quality control,combustion temperature and sulfur-nitrate production control technology were developed,so that the compressive strength of fluxed pellet was more than 2 200 N,the SO2 production amount was 20%lower than that of acidic pellet,and the SO2 and NOx were reduced by 75%and 53%respectively than that of sinter.The blast furnace smelting integrated technology of high proportion pellet was developed.And the proportion of blast furnace pellet was increased from 20%to 80%,the fuel ratio was decreased by 11 kg/t,and the SO2 and NOxemission of per ton iron was reduced by 50% and 26% respectively.Quantitative analysis method of energy saving and emission reduction during the iron-making life cycle and the continuous improvement direction were put forward,and the source and process pollutant reduction was realized.It has been successfully extended to the online2 000 m^3 blast furnace,3 000 m^3 blast furnace and 3 000 m^3 blast furnace in Laoting plant of HBIS Group.It opens up a new direction for reducing the total pollutant emission of domestic iron and steel industry.