基于铁浴还原的石煤改质含钒转炉钢渣资源化利用的基础研究

At present, vanadium separating from V-bearing steelmaking slag only places emphasis on the obtaining of vanadium and ignores the utilization of other major composition in steelmaking slag. Given this, based on the early research results, according to the composition characteristic of V-bearing steelmaking slag and stone coal, the project aims to carry out the research on the enrichment of vanadium and utilization of other major composition in V-bearing steelmaking slag by stone coal midification under iron-bath smelting reduction condition. The evolution of structures and compositions of the phases in V-bearing steelmaking slag and stone coal will be revealed by combining the dynamic in situ means and fine static analysis methods, and the interaction mechanism between vanadium and carbon and the physical-chemical behaviors of vanadium during the reduction process will also be clarified. The rules concerning the migration, enrichment and distribution of vanadium and other elements during the reduction process will be elucidated. The mechanism of selective formation of C2S and its structural change, and the theory of slag self-pulverization caused by C2S structural change will be studied by physical and chemical method as well as modern analytical techniques. The new technical directions for the recycling utilization of V-bearing steelmaking slag and stone coal will be designed, as well as the related theoretical basis will also be provided.

目前含钒转炉钢渣提钒工艺主要侧重于有价元素钒的获取，而忽略了渣中其它主要成分的资源化利用。本项目基于项目组前期的工作积累和发现，依据含钒转炉钢渣和石煤的成分特点，综合考虑钢渣、石煤中主要成分的利用，提出在铁浴碳热还原条件下，利用石煤高温改质含钒转炉钢渣。通过研究还原条件下钒的物理化学行为和在渣金间的迁移规律，以及钢渣中C2S相优势生成和晶型转变的条件，实现铁水钒富集和转炉钢渣自粉化，既有效提高了含钒转炉钢渣、石煤中钒的收得率，也可解决钢渣中铁回收、尾渣利用等一系列问题。本项目的完成将为含钒转炉钢渣和石煤的高效资源化利用提供理论依据和技术支撑。

含钒石煤和含钒转炉钢渣中有价元素钒的品位低，提取成本大；同时由于转炉钢渣硬度高、易磨性差，微粉化困难，限制了其大宗量应用。为实现含钒石煤和含钒转炉钢渣的高值大宗量利用，本项目提出了铁浴还原含钒石煤改质的含钒转炉钢渣，实现铁水富钒和尾渣自粉化的含钒资源利用新方法。本项目对含钒石煤矿相组织和钒元素的赋存状态、石煤改质转炉钢渣的矿相组织及含钒相的变化、不同铁浴条件下钒、磷等元素在渣金间的迁移、石煤改质转炉钢渣还原尾渣的自粉化、磁性钒铁尖晶石的生成等相关内容进行了研究。研究结果表明，通过理论计算可确定合适的复合改质剂种类和加入量，并通过石煤复合改质，可改变含钒转炉钢渣还原后尾渣的矿相组织，使还原尾渣保持铁浴熔融，从而促进磷钒的渣金间迁移和还原尾渣的自粉化。本项目研究结果为含钒石煤和含钒转炉钢渣等低品位含钒资源的高值大宗量利用提供了共性理论依据和技术支撑，将有利于推动低品位含钒资源的全量资源化综合利用。