铁水预处理高效脱硫工艺

HIGH EFFICIENCY DESULFURIZATION PROCESS OF HOT METAL PRETREATMENT

随着我国钢铁行业的发展,对钢中硫含量的要求越来越严格,一般要求钢中[S]的质量分数不大于0.02%,而一些对硫含量要求更为严格的钢种,则要求成品中硫含量小于0.005%。为了进一步提升铁水脱硫能力、降低铁水消耗,本文分析了KR预处理工艺过程中铁水温度、脱硫剂单耗、初始硫含量、搅拌时间对脱硫率的影响,针对KR工艺优化前存在的问题进行了分析,基于热力学平衡计算,建立了适宜的炉渣碱度、FeO以及温度的控制方式,更有利于获得碱度合适、流动性较好的炉渣,优化了渣钢反应的动力学条件。通过工艺优化,基于不同的铁水条件,调整装入量在78~80 t、优化搅拌头转速、搅拌时间以及搅拌深度,KR脱硫剂单耗为0.123 kg/(t·s),下降了13.38%,平均搅拌时间缩短了1.04 min,脱硫剂消耗减少了2.58 kg/t,吨钢脱硫渣量减少了1.97 kg/t,全天最高脱硫包数78包,全月有9次单班KR脱硫完成27炉,KR各项工艺指标均得到改善,形成了高效低成本KR冶炼工艺,降低了冶炼过程渣料消耗量,减少了冶炼成本,实现了KR高效低成本脱硫。

With the development of China's steel industry,the requirements for sulfur content in steel are becoming increasingly strict.Generally,the quality fraction of steel grades[S]is required to be no more than 0.02%,while some steel grades with stricter sulfur content requirements require the sulfur content in the finished product to be less than 0.005%.In order to further enhance the desulfurization capacity of hot metal and reduce its consumption,this paper analyzes the effects of hot metal temperature,desulfurizer consumption,initial sulfur content,and stirring time on the desulfurization rate during the KR pretreatment process.Based on thermodynamic equilibrium calculations,suitable control methods for slag alkalinity,FeO,and temperature are established to obtain slag with appropriate alkalinity and good fluidity,and the kinetic conditions of slag steel reaction are optimized.Through process optimization,based on different hot metal conditions,the loading amount was adjusted from 78 to 80 tons,and the stirring head speed,stirring time,and stirring depth were optimized.The unit consumption of KR desulfurizer was 0.123 kg/(t·s),a decrease of 13.38%,and the average stirring time was shortened by 1.04 minutes.The consumption of desulfurizer was reduced by 2.58 kg/t,and the amount of desulfurization slag per ton of steel was reduced by 1.97 kg/t.The highest number of desulfurization packages in the whole day was 78 packages.There were 9 single shifts of KR desulfurization completed in 27 furnaces throughout the month,and KR's various process indicators were improved,forming an efficient and low-cost KR smelting process,reducing slag consumption in the smelting process,reducing smelting costs,and achieving KR's efficient and low-cost desulfurization.