高铁铝土矿/高铁锰矿协同作用下有价组元迁移行为及强化利用机制

High iron bauxite and high iron manganese are Fe-Al and Fe-Mn composite ore respectively in China, which own quite big reserve. As the minerals are superfine and conjoined with each other, it is difficult to be separated through physical beneficiation. Along with continuous heavy demand of iron ore, bauxite and manganese ore resources in our country, the high effective utilization of complex ore resources including high iron bauxite and high iron manganese has been listed into the national long-term science and technology development planning. The development of efficient utilization technologies of high iron bauxite and high iron manganese has great significance on resource security of China. This project puts forward the new process route of high iron bauxite / high iron manganese selective reduction - magnetic separation - smelting -leaching - comprehensive utilization of valuable elements. For the key link of the new technology, some key scientific problems, such as multiple heterogeneous reaction thermodynamics and kinetics of mineral components, reconstruction behavior of microscopic minerals phase, formation and growth characteristics of metallic iron particle, thermodynamic activity of MnO and SiO2 in slag during the process of preparing manganese alloys, allocation pattern of Mn and Si in slag - metal interface, solidification characteristics of slag, are researched to illuminate the selective migration behavior and strengthening utilization mechanism of valuable elements during the new process. The researches would lay foundation of efficient utilization, perfect theory and innovate method for the utilization of high iron bauxite and high iron manganese.

高铁铝土矿/高铁锰矿是我国重要铁铝、铁锰复合矿产资源，储量巨大。由于矿中矿物颗粒微细、嵌布胶合、密切共生，分离极为困难。随着我国对铁矿、铝土矿、锰矿等矿产资源的持续大量需求，高铁铝土矿/高铁锰矿等复合矿产资源的高效综合利用已列入国家中长期科技发展规划，开发其综合利用技术对于我国矿产资源的安全具有重要意义。本项目提出基于协同作用的高铁铝土矿/高铁锰矿选择性还原-磁选-熔炼-浸出有价组元综合利用新工艺。针对新工艺的关键环节，通过研究新工艺过程中组元矿物的多元多相反应热力学和动力学，矿石微观物相重构行为，金属铁颗粒形成及长大特性，锰铁合金制备过程MnO、SiO2在炉渣体系的热力学活度以及Mn、Si组元在渣-金相间的分布规律、熔渣凝固特性等科学问题，阐明新工艺过程有价组元选择性迁移行为及强化利用机制，为高铁铝土矿/高铁锰矿协同综合利用奠定基础，实现高铁铝土矿/高铁锰矿综合利用的理论完善和方法创新。

高铁铝土矿/高铁锰矿是我国重要铁铝、铁锰复合矿产资源，储量巨大。由于矿中矿物颗粒微细、嵌布胶合、密切共生，分离极为困难。随着我国对铁矿、铝土矿、锰矿等矿产资源的持续大量需求，高铁铝土矿/高铁锰矿等复合矿产资源的高效综合利用已列入国家中长期科技发展规划，开发其综合利用技术对于我国矿产资源的安全具有重要意义。本项目提出了基于协同作用的高铁铝土矿/高铁锰矿选择性还原-磁选-熔炼-浸出有价组元综合利用新工艺。针对新工艺的关键环节，开展高铁铝土矿/高铁锰矿协同作用下选择性还原热力学、铁矿物还原动力学及金属铁颗粒生长过程、高铁铝土矿/高铁锰矿选择性还原磁选分离、高铝富锰渣冶炼锰铁合金、富铝渣浸出提铝等关键内容的研究。研究表明，高铁锰矿中的MnO可取代高铁铝土矿中部分铁铝尖晶石中的FeO，可将还原温度由831℃降低至725℃、CO体积分数由92%降低到62%，还原条件得到大幅改善；在高铁铝土矿还原过程中添加高铁锰矿，还原过程中的液相量增多，有利于金属铁颗粒的长大和聚集；适宜的高铁铝土矿/高铁锰矿协同还原工艺参数为铝锰矿物比7/3、碳氧比0.8、还原温度1300℃、还原时间90 min、磨矿时间5 min、磁场强度100 mT，该条件下铁的回收率为90.6%；以高铝富锰渣为原料，进行富锰渣冶炼锰铁合金的实验研究，冶炼过程优化工艺参数为：三元碱度0.7、配碳量1.1、冶炼时间60 min和冶炼温度1550°C。此实验条件下，锰铁合金中锰回收率可达80.47%，铁回收率可达97.70%，锰含量77.76%，铁含量12.13%，碳含量7.73%，硅含量0.168%，P含量0.14%，S含量0.008%各指标均优于FeMn75C7.5、FeMn70C7.5、FeMn65C7.0对应的国标要求，是优质高碳锰铁。适宜的炉渣浸出工艺条件为浸出时间100 min，浸出温度60℃，Na2CO3浓度100 g/L，液固比12.5，在此条件下，炉渣的浸出率为86.20%。本项目研究阐明了新工艺过程有价组元选择性迁移行为及强化利用机制，为高铁铝土矿/高铁锰矿协同综合利用奠定基础，完善了高铁铝土矿/高铁锰矿综合利用相关的技术和理论。