摘要
电渣重熔是一种利用电流通过熔渣时产生的电阻热作为热源进行熔炼的净化钢液手段。因为其冶炼产品具有金属洁净、组织致密、成分均匀、表面光洁等优点,广泛应用于高端金属材料制备。为了保证熔渣的导电性,电渣渣系均含有一定CaF_(2),冶炼过程挥发严重,污染环境;氟化物挥发造成渣系成分波动大进而影响冶炼过程和产品质量。从渣系组成、冶炼环境、热力学和动力学几方面出发,讨论了影响渣系中氟化物挥发的因素,探讨了降低氟化物挥发的有效方法。重点介绍了CaF_(2)、w((CaO))/w((SiO_(2)))、w((CaO))/w((Al_(2)O_(3)))对渣系挥发的影响。降低渣中CaF_(2)含量、增大w((CaO))/w((SiO_(2)))、减小w((CaO))/w((Al_(2)O_(3)))可有效减少渣中氟化物挥发;讨论了利用碱金属氧化物(Li_(2)O、Na_(2)O、K_(2)O)、TiO_(2)、B_(2)O_(3)代替CaF_(2)开发低氟渣的可能性。利用Na_(2)O、TiO_(2)、B_(2)O_(3)等代替CaF_(2)是未来低氟/无氟渣开发的重要方向之一;综述了冶炼温度和环境湿度等对含氟渣系挥发的影响规律。降低冶炼温度、提高升温速率、对渣系预熔和保持干燥均可有效抑制氟化物挥发;基于电渣冶金渣系挥发热力学和动力学研究现状,介绍了炉渣分子离子共存理论计算渣系组元活度的适用性,总结了渣系挥发的动力学机理,归纳了电渣重熔过程中含氟渣挥发的限制性环节。分子离子模型对常见渣系组元活度计算具有很高的准确性,对其他特殊渣系的适用性还有待进一步验证。未来渣系挥发动力学研究应重点关注参与挥发反应的阴阳离子由本体向反应界面传质过程,以及反应生成物的形核、长大、气泡化的过程这2个限制性环节,以减少氟化物挥发。
Electroslag remelting is a method to purify molten steel,using the resistance heat generated by the current passing through the slag as a heat source for smelting.The products prepared by electroslag remelting have the advantages of high purity,dense structure,uniform composition,and smooth surface,so electroslag remelting is widely used in the preparation of high-end metal materials.To ensure the conductivity of the slag,the electric slag system contains a certain amount of CaF_(2),which causes severe volatilization during the smelting process and pollutes the environment.The volatilization of fluoride causes significant fluctuations in slag composition,which affects the smelting process and product quality.From the aspects of slag composition,smelting environment,thermodynamics and kinetics,the factors affecting the volatilization of fluoride and the effective methods to reduce the volatilization of fluoride in the slag system are discussed.The effects of CaF_(2),w((CaO))/w((SiO_(2)))and w((CaO))/w((Al_(2)O_(3)))on the volatilization of slag system are introduced.Reducing the content of CaF_(2),increasing the w((CaO))/w((SiO_(2)))and decreasing the w((CaO))/w((Al_(2)O_(3)))in the slag would effectively reduce the volatilization of fluoride in the slag.And the possibility of using alkali metal oxides(Li_(2)O,Na_(2)O,K_(2)O),TiO_(2) and B_(2)O_(3) instead of CaF_(2) to develop low fluorine slag is discussed.One of the important directions for future development of low fluorine/non fluorine slag is to replace CaF_(2) with Na_(2)O,TiO_(2),B_(2)O_(3),etc.The effects of smelting temperature and environmental humidity on the volatilization of fluorine-containing slag are reviewed.Reducing the smelting temperature,increasing the heating rate,premelting the slag system and maintaining dryness could effectively inhibit the volatilization of fluoride.On the basis of investigating the current research status of volatilization thermodynamics and kinetics of electric slag system,the applicability of the slag molecular ion co
作者
邱国兴
介光辉
杨永坤
李小明
QIU Guoxing;JIE Guanghui;YANG Yongkun;LI Xiaoming(College of Metallurgical Engineering,Xi’an University of Architecture and Technology,Xi’an 710048,Shaanxi,China)
出处
《钢铁》
CAS
CSCD
北大核心
2024年第10期1-10,共10页
Iron and Steel
基金
中国博士后科学基金资助项目(2022M720982)
陕西省自然科学基金青年基金资助项目(2021JQ-502)。
关键词
电渣冶金
渣系
CaF_(2)
挥发
热力学
动力学
electroslag metallurgy
slag
CaF_(2)
volatilization
thermodynamics
dynamics
