摘要
针对“改质+还原”两步法钢渣在线重构工艺过程涉及的物相与黏度协同调控问题,采用FactSage模拟软件对SiO_(2)-CaO-MgO-Al_(2)O_(3)-FexO五元渣系物相组成和液相区分布进行研究,并结合黏度试验及修正后的Einstein-Roscoe公式对渣系的黏度进行了分析,确定各成分含量变化对重构不同阶段熔渣的物相及黏度的影响规律。结果表明,钢渣主要物相包括金属氧化物、硅酸盐类、铝酸镁、镁硅钙石(Ca_(3)MgSi_(2)O_(8))等,铁元素以Ca_(2)Fe_(2)O_(5)、Fe3O_(4)、FeO形式存在,自由CaO质量分数由2.49%至5.81%不等;提高酸性改质剂比例,改质渣析出物相以铝酸钙、硅酸二钙、偏硅酸钙、铝黄长石(Ca_(2)Al_(2)SiO_(7))、钙长石(Ca_(2)Al_(2)Si_(2)O_(8))类物相为主,后期铝酸镁完全消失,转变为Ca_(2)Al_(2)SiO_(7)和CaMg_(2)Al_(16)O_(27);还原阶段铁氧化物不断还原为金属铁与渣相分离,提铁尾渣中堇青石(Mg_(2)Al_(4)Si_(5)O_(18))和辉石类物相析出范围增大,当碱度由1.47降低至0.95时,偏硅酸钙和钙长石析出显著增多,自由CaO完全消解。改质剂的加入使钢渣的熔化性温度由1450℃以上显著降低至1330℃,FeO、MgO含量增加可降低熔化性温度、改善熔渣流动性,而碱度和Al_(2)O_(3)的影响规律恰好相反;还原阶段尾渣碱度、FeO质量分数对熔化性温度影响显著,碱度为0.95、FeO质量分数为3.69%时,尾渣熔化性温度约为1350℃,FeO质量分数降低至0时尾渣熔化性温度提高了约27℃,需保证供热以克服流动性恶化问题并满足还原耗热;MgO和Al_(2)O_(3)质量分数对熔化性温度影响不大。综上,基于适宜的渣系成分及工艺调控,“两步法”重构钢渣方案可以满足熔池内物相反应及均质行为对熔渣流动性的要求。
Aiming the problem of synergetic control on phases and viscosity during the"modification and reduction"two-step steel slag online reconstruction process,phases and viscosity of SiO_(2)-CaO-MgO-Al_(2)O_(3)-FexO multi-molten slag were discussed by using Factsage simulation software,viscosity test and revised Einstein-Roscoe formula,then the influence of each component content variation on phases and viscosity of steel slag ware confirmed at different reconstruction stages.The results show that,the main phases of steel slag include metal oxides,silicates,magnesium aluminate,merwinite(Ca_(3)MgSi_(2)O_(8))and so on,iron exists in the form of Ca_(2)Fe_(2)O_(5),Fe3O_(4) and FeO,the mass percent of free CaO varies from 2.49%to 5.81%.The precipitated phases of modified slag are mainly calcium aluminate,dicalcium silicate,calcium metasilicate,aluminium melilite(Ca_(2)Al_(2)SiO_(7))and akermanite(Ca_(2)Al_(2)Si_(2)O_(8))when the proportion of acid modifier increased,and magnesium aluminate completely disappeared and transformed into Ca_(2)Al_(2)SiO_(7) and CaMg_(2)Al_(16)O_(27) in the later stage of modification.The iron oxides are continuously reduced to metallic iron and separated from the slag phaseinreduction stage,the range of cordierite(Mg_(2)Al_(4)Si_(5)O_(18))and pyroxene phase precipitation increases in tailings after iron extraction,and as the basicity decreasing from 1.47 to 0.95,calcium metasilicate and anorthite increase significantly,and free CaO was digested completely.The melting temperature of steel slag decreases significantly from above 1450℃to 1330℃with the addition of modifier,the melting temperature was decreased and the liquidity was improved caused by the increase of FeO and MgO mass percent,also the reduced basicity and Al_(2)O_(3) mass percent.In the reduction stage,the basicity and FeO mass percent of the tailings effect on the melting temperature significantly.The melting temperature of the tailings is about 1350℃when R=0.95,w(FeO)=3.69%,and the melting temperature of the tailings increase
作者
甄常亮
程翠花
张巧荣
赵凯
ZHEN Changliang;CHENG Cuihua;ZHANG Qiaorong;ZHAO Kai(School of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063210,Hebei,China;Technical Centre,HBIS Group Tang Steel Company,Tangshan 063000,Hebei,China)
出处
《钢铁》
CAS
CSCD
北大核心
2023年第7期144-153,共10页
Iron and Steel
基金
中央引导地方科技发展资金资助项目(226Z3802G)。
关键词
钢渣
重构
改质
还原
物相
黏度
steel slag
reconstruction
modification
reduction
phase
viscosity
