高炉炉缸铁水中钛析出动力学及多物理场协同护炉机制基础研究

The safety problem of hearth sidewall has become one of the limiting factors for the long campaign life, high efficiency and low cost of modern blast furnace. Adding titanium bearing materials into blast furnace is the core measure for hearth safety maintenance. Thermodynamic study on the changes of (TiO2)-[Ti]-Ti(C,N) has been done. However, the formation and distribution of titanium compounds in hearth sump are the coupled results by thermodynamics, kinetics, reactor property and inner multi physics fields. According to the research ideas of metallurgical reaction engineering, the kinetic features of titanium precipitation from hot metal are obtained by high temperature physical simulation experiments and microscopic observation and analysis, which are tested under different temperature, stirring intensity and initial concentration. Then chemical reaction rate constant and mass transmission coefficient are confirmed by building different reaction models and adopting sectional stepwise method. Based on this, the user defined functions are developed and the gotten kinetic parameters could be applied to macro numerical simulation. Effects of hearth structure and property, tapping operation, titanium addition method (the whole or partial) and other factors on the flow filed, temperature filed, concentration filed and titanium compound distribution are studied. The temporal and spatial distribution, the synergistic effect and the maintenance efficiency could be confirmed. The quantificational evaluation standards are promoted. The scientific and universal research methods and control plans could be provided for titanium bearing protection into blast furnace. Process analysis and collaborative evaluation mechanism are explored based on transmission and reaction coupling.

炉缸侧壁的安全问题已成为现代高炉长寿、高效、低成本冶炼的限制性环节之一。加钛护炉是炉缸安全维护的核心手段。前人主要进行了(TiO2)-[Ti]-Ti(C,N)转变的热力学研究，但实际死铁层内钛化物的生成及分布是热力学、动力学、反应器材质及内部多物理场耦合作用的结果。本课题拟基于冶金反应工程学研究思路，通过高温物理模拟实验及微观观测分析，掌握不同温度、搅拌强度、初始浓度下铁水中钛析出的动力学特征，并建立不同反应过程模型及采用“分段尝试法”确定其化学反应速度常数和质量传输系数，在此基础上开发用户自定义函数将动力学参数应用于宏观数值模拟，研究高炉炉缸结构特性、出铁操作、Ti加入方式(整体或局部)等对反应器中流场、温度场、浓度场、钛化合物的时空分布、协同效应及护炉效率的影响，提出定量化的评价标准，为高炉加钛护炉提供科学性、普适性的研究方法和控制思路，探寻基于“三传一反”的过程解析和协同评价机制。

炼铁高炉炉缸烧穿是制约高炉安全生产和长寿高效冶炼的关键环节。加钛护炉是防止炉缸烧穿的重要手段，但是如何有效的加钛护炉，是炉缸炉底内铁水流场温度场、砖衬温度场以及钛溶解和TiCN析出的热力学及动力学综合作用的系统工程，此前相关研究较少，在实际高炉生产中也难以做到准确监控，炉缸烧穿事故屡有发生，带来重大经济损失和安全威胁。本项目研究了不同条件下高炉炉缸反应器中流场、温度场、浓度场、钛化合物的时空分及协同效应，研究了炉缸结构、耐材搭配、出铁参数、冷却制度等对加钛护炉和炉缸安全的影响，通过热力学动力学计算及热态试验研究了钛溶解和TiCN的析出规律，对比了生产中有代表性的传热法和隔热法高炉加钛护炉的实际情况和护炉效果，探寻了科学性、普适性的加钛护炉机制，为高炉护炉时钛加入量、时间点、周期、冷却强度及生产调节的优化提供了控制思路和研究方法，并在此基础上开发了高炉炉缸炉底温度场、侵蚀内型及钛护炉物析出在线监测诊断模型，科研成果实现了产品化及产业化，已应用于国内外数十个大型钢铁企业的上百座高炉，建立了炉缸安全大数据平台，在行业内推广了数字化炉缸安全监测及预警机制。