非均相脱磷渣中磷在相间的分配及传递研究

The phosphorus content of ore from inner Mongolia is medium-height with about 0.2% phosphorus content in hot metal and the content in Mongolia ore is higher which is imported large quantity to reduce the using number of ores from Australia and Brazilia for its high price..The requirement to steel with low and ultra-low content of phosphorus is increasing and the low phosphrus steel is often refined by single slag method which has shortages of large slag quantity, instable refining operation, serious splashing, short lining life and low ratio of destination hit..Low cost and high efficiency dephosphorization agent is required to reduce consumption of raw material and energy for metallurgy industry to realize development with endurance..Now oxidation process is the main dephosphorization method and CaO-FeOn-CaF2 slag system is used mainly during prudcuting and studying. And the content of studying is focused on dephosphorizing dynamics and thermodynamics of dephosphorization slag with different components. There is little study on how type and ratio of solid phase particle in dephosphorization slag effects on dephosphorization..In the project, based on thermodynamics calculation and combined with present measured method, it will be studied how composition and ratio of solid phase particle and type and ratio of solid phase particle in dephosphorization slag at high temperature effect on dephosphorizing dynamics and thermodynamics and how phosphorus dispenses in solid and liquid phase. In short, the dephosphorization process will be studied in detail..The project will provide theoretical instruction for exploiting high effeciency and low cost dephosphorization agent and will enrich the foundation of oxidation dephosphorization.

内蒙古地区的铁矿属于中高磷矿石，铁水中磷含量在0.2%左,为了减少价格较高的澳矿和巴西矿的用量，大量进口蒙古矿，其磷含量更高。低磷或超低磷钢的需求越来越多，目前采用单渣法冶炼低磷钢，存在着渣量大、冶炼操作不稳定、喷溅严重、炉衬寿命短和终点命中率低的缺点，为了实现可持续发展，又要求冶金生产原料和能量消耗越来越低，需要低成本高效的脱磷剂。目前脱磷以氧化脱磷为主，生产和研究以CaO-FeOn-CaF2渣系为主，研究内容主要集中在不同成分脱磷渣的脱磷热力学和动力学，涉及脱磷渣中固相质点种类和其所占比例对脱磷影响方面的研究很少。本项目以热力学计算为基础通过实验结合现代化检测手段，对脱磷渣在高温下的固相质点组成和比例、固相质点的种类和比例对脱磷的热力学和动力学的影响、磷在渣中固液两相中的分配及传递进行研究，对脱磷过程进行细致的研究。本项目将为开发高效、低成本的脱磷剂提供理论指导，也将丰富氧化脱磷的基础

我国铁矿磷含量偏高，铁水中磷含量偏高，目前高磷铁水脱磷采用的方法是双渣或部分换渣法，渣量大。项目研究了非均相渣中磷在2CaO·SiO2颗粒和液相渣及其渣中其它类型颗粒中的分配情况，研究了磷在非均相脱磷渣2CaO·SiO2、CaO·SiO2、CaO颗粒中的扩散速率以及非均相渣中不同固相颗粒含量时脱磷动力学。研究得出，磷在2CaO∙SiO2固相中磷的固溶量为8.87%，铁酸钙相中磷的固溶量为1.2%，玻璃相中磷的固溶量为1.3%。磷在固相颗粒中扩散时，分为4层，分别为：固相颗粒层、扩散层、固溶体层、渣层，磷在固溶体层有明显的富集，明显高于渣层中的磷含量，脱磷产物扩散进入2CaO·SiO2和CaO颗粒中较为明显，而在CaO·SiO2固相颗粒中扩散较浅。磷在2CaO·SiO2中的扩散速率为6.43×10-9m2/s，磷在CaO颗粒中的扩散系数为3.16×10-9m2/s，磷在CaO·SiO2中的扩散速率为9.27×10-10m2/s。非均相脱磷剂与传统的纯液相相比，虽然有着很好的脱磷效果，但不是渣中固相越多，脱磷效果就越好，1350°C的条件下，脱磷的限制性环节是磷在渣中的扩散，钢液中磷的传质系数为0.00564~0.08002cm∙s-1，在渣中的传质系数为0.1133~0.3009×10-4cm∙s-1。