转炉钢渣中镁铁锰尖晶石群(Mg,Fe,Mn)Fe2O4的析出、长大和分离研究

钢渣的综合循环利用在整个钢铁工业的可持续发展过程中起着尤为重要的作用。将钢渣掺入水泥制备钢渣水泥是一个有效且高效的利用方式，然而钢渣中难以分离的铁氧化物和RO相的存在限制了其在建材领域的应用。前期研究对CaO-SiO2-FexO-MgO体系钢渣进行了固相改质处理，实现了钢渣中铁氧化物和RO相向强磁性镁铁尖晶石的转变。本项目进一步针对CaO-SiO2-FexO-MgO-MnO体系钢渣进行固相改质，并对改质后形成镁铁锰尖晶石相的组成、形态和尺度进行研究。通过成分改质和工艺参数调整，探索化学成分、煅烧温度和保温时间对镁铁锰尖晶石形成过程的影响规律；借助热力学计算，研究改质过程中主要矿物相的转变机理；利用热重分析，建立镁铁锰尖晶石形核和长大的动力学模型；参照Rietveld精修分析结果，解析镁铁锰尖晶石的晶体结构构建过程。该项目的实施可以对冷态钢渣的改质处理提供理论依据和技术基础。

The comprehensive recycling of steel slag plays a particularly important role in the sustainable development of the entire steel industry. The incorporation of steel slag into cement to prepare steel slag cement is an effective and efficient way. However, the existence of iron oxide and RO phase which are difficult to separate in steel slag limits its application in the field of building materials. In the previous study, the solid phase modification of CaO-SiO2-FexO-MgO system steel slag was carried out, and the transformation of iron oxide and RO phase to ferromagnetic (Mg,Fe)Fe2O4 spinel in steel slag was realized. In this project, the solid phase modification of CaO-SiO2-FexO-MgO-MnO system was carried out, and the composition, morphology and scale of the (Mg,Fe,Mn)Fe2O4 phase formed after modification were studied. Through the modification of composition and adjustment of process parameters, the influence of chemical composition, calcination temperature and holding time on the formation process of (Mg,Fe,Mn)Fe2O4 phase was explored. The thermodynamic calculation was used to study the transformation mechanism of main mineral phases during the upgrading process. The kinetic model of nucleation and growth of (Mg,Fe,Mn)Fe2O4 phase was established. The crystal structure of (Mg,Fe,Mn)Fe2O4 phase was analyzed with reference to the results of Rietveld refinement analysis. The implementation of the project can provide theoretical basis and technical basis for the reformation of steel slag.