微波场作用下白云鄂博稀土尾矿原位合成铁基多功能金属陶瓷基础研究

As paragenetic and associated tailings, Bayan Obo rare earth tailings which contain many valuable elements (such as rare earth, niobium and iron) are potential secondary resources. The project will be focused on microwave-radiated Bayan Obo rare earth tailings. Furthermore, the special microwave interaction mechanisms will be unearthed during the in-situ synthesis of multi-functional Fe-based cermets. And the expected results can not only widen the utilization of Bayan Obo rare earth tailings but also provide reference for future studies on microwave metallurgy in the treatment of multi-metal associated minerals. The implementation of the project is divided three steps: Firstly, the preparation conditions and key parameters are established during microwave in-situ synthesis of multi-functional Fe-based cermets from Bayan Obo rare earth tailings. Secondly, the effects of various factors involving microstructures, morphology evolution, phase transformation, distribution of nanoparticles and rare earth constitutes on targeted material properties are revealed. And also, microwave effects and their mechanisms in the process of energy transfer and mass diffusion are explored in details. Thirdly, pilot-scale studies are conducted by choice of the as-obtained optimized process, which gradually achieve large scale and industrialization of cermet synthesis from Bayan Obo tailings. Meanwhile, we will try to extend the novel approach to Bayan Obo raw ores and concentrates, expect to get a innovative process distinct from Baotou Steel conventional process of rare earth separation-ironmaking-steelmaking and finally realize the strategic vision of integrated exploitation of Bayan Obo multi-metal resources.

白云鄂博稀土尾矿为典型的共生、伴生难处理尾矿，其中含大量稀土、铌、铁等有价矿物组分，是潜在的二次资源。本课题立足于微波辐照白云鄂博稀土尾矿，在原位合成铁基多功能金属陶瓷的同时深入挖掘微波的独特作用机理，不仅可以有效拓宽稀土尾矿的利用途径，而且为微波冶金在多金属共伴生矿上的应用提供研究参考。开展此项目分“三步走”：1）探索白云鄂博稀土尾矿原位微波合成铁基多功能金属陶瓷的实验条件与关键参数。2）研究微观组织、形貌演变、相转变、纳米颗粒分布及稀土组元等因素对目标产物性能的影响，探讨制备过程中微波效应及其在能量传递及物质扩散中的作用机理。3）利用获取的最佳工艺进行中试实验，逐步达到白云鄂博尾矿制备金属陶瓷的规模化与工业化。同时尝试将此推广到白云鄂博原矿及精矿中，获得一种有别于包钢传统的稀土分离-炼铁-炼钢工艺的新工艺，实现白云鄂博矿多金属资源综合利用的战略远景。

微波独特的空间能量传递与原位能量转化方式，能够在材料内部建立均匀的温度场分布，促进材料微结构与相分布的匀质化。因此，微波冶金在白云鄂博多金属伴生矿综合利用方面具有广阔的前景。本项目以白云鄂博矿为研究对象，微波制备了Fe/Fe2SiO4-FeAl2O4基金属陶瓷、设计并合成了梯度结构纳米透辉石增韧玻璃陶瓷及FeSi2-辉石金属陶瓷等，系统研究了各体系的反应过程、微观形貌、相组成及性能等，阐述了微波热效应与非热效应对析晶过程的影响机制，明确了白云鄂博矿的微波特性。本项目的研究结果可以为微波冶金在多金属伴生矿上的应用提供理论指导与技术支持。