转型发展形势下的转炉炼钢科技进步

Technological progress of BOF steelmaking in period of development mode transition

对中国钢铁工业转型发展时期需重点关注的转炉炼钢工艺技术进行了分析论述,认为:1)较低底吹搅拌强度的复吹转炉应将底吹元件减少至4~6支,并采取根据钢水碳氧积对底吹元件"动态维护"等措施,提高熔池实际搅拌效果,而大量生产低碳、超低碳钢品种的钢厂应将底搅强度逐步增加至0.1~0.15 m^3/(t·min);2)随钢铁工业去产能逐步深入,会有相当数量转炉富余、闲置,有条件钢厂应利用其进行铁水脱磷预处理,采用"脱磷转炉+脱碳转炉"炼钢工艺技术。为此,脱磷转炉须采用大底吹搅拌强度,并注意解决脱碳转炉热量不足问题;3)应加强转炉炉气分析吹炼控制技术研发,具备条件钢厂可尝试首先取消"TSO"测定,由炉气分析系统承担碳含量控制任务,在此基础上逐步对炉气分析控制系统改进完善,最终由其承担转炉冶炼控制任务;4)Simense VAI、Dofasco公司等开发了转炉全自动出钢技术,将转炉自动化、智能化生产提高到新水平,建议国内高水平钢厂加快采用转炉全自动出钢技术。

Four important steelmaking technologies to be developed in the coming transition period of the Chinese steel industry are discussed in this article.（ 1） In BOF steelmaking plants which now use mild bottom blown intensities,number of the bottom tuyeres of the converter should be reduced to 4 - 6. The technology of dynamic maintenance of the bottom tuyeres based on the product of final [% C] and [% O]can be adopted to improve the actual bottom stirring results. Furthermore,for steel plants which mainly produce low and ultra-low carbon steels,the bottom blowing intensity should be progressively increased to0. 1 - 0. 15 m-3/（ t·min）.（ 2） In the coming transition period,steelmaking converters will become surplus in many plants. These converters can be used for hot metal dephosphorization pretreatment. Using the＂DeP ＋ De-C＂steelmaking technology,strong bottom stirring must be applied in De-P converter and attention should be paid on the problem of heat shortage in De-C converter.（ 3） Investigation on controlling BOF blowing based on off gas information should be strengthened. In some high-level plants,＂TSO ＂measurement of the sub lance can be firstly cancelled and the end carbon control can be made by the off gas system. With continuous improvement,the whole blowing will be controlled finally by the off gas system.（ 4） Recently,automatic tapping of BOF steelmaking was successfully developed by Simense VAI,Dofasco,etc. It enhanced the automatic and intelligent operation of BOF steelmaking to a new higher level. Chinese steelmaking plants should adopt this technology.