高铁赤泥作为拜耳法工艺中产生的固体残渣，是一种典型的二次资源。赤泥的资源化利用及无害化处理，对提高资源利用率和改善生态环境意义重大。本项目针对高铁赤泥的资源化问题，提出直接还原—磁选—浸出的新思路，运用矿物加工和提取冶金原理和方法，开展赤泥中铁、铝等金属的高效分离研究。具体内容包括：研究不同粒级高铁赤泥工艺矿物学，确立铁、铝、硅等氧化物在还原焙烧及钠基添加剂作用下反应的热力学关系，获得高铁赤泥中铁和其他元素分离的热力学条件；运用MPE软件、微观结构分析等技术，研究还原焙烧过程中铁、铝、硅等矿物物相的转变规律及其微观结构的演变，查明金属铁晶粒生长的动力学控制特征；研究磁场和浸出剂作用下铁、铝、硅等元素的富集规律。本项目的开展将为揭示直接还原-磁选-浸出工艺中铁、铝高效分离的微观机制，实现高铁赤泥的资源化利用提供理论指导和技术支持。

The high-iron content red mud, as a typical secondary resource, is the tailing produced during extracting alumina from bauxite with the Bayer process. The treatment and utilization of red mud with high iron content is of great significance to improve resource utilization and ecological environment. To utilize such resources, a novel process of direct reduction roasting- magnetic separation- leaching is proposed in this project. And studies on the separation and recycling of Fe-Al in red mud have been carried out by using the theory and methods including mineral processing and extractive metallurgy. The main contents can be described as follows: Investigation on the mineralogy characters of red mud with different grained sizes; Building up thermodynamic relations of ferrous, aluminiferous and siliceous oxides in reduction process with or without the addition of sodium-based additives; Setting up thermodynamic conditions to separate iron and aluminium; Studying the phase transformation and structural evolution of ferrous, aluminiferous and silaceous minerals in the reduction roasting process by means of MPE and micro-structure analysis; Exposition the reduction dynamics of iron grains; Finding out the enrichment laws of ferrous, aluminiferous and silaceous elements in the role of magnetic field and leaching agents. This project will reveal the micro-mechanism of high-efficiency separation of ferrous and aluminiferous in the process of direct reduction roasting- magnetic separation- leaching, and provide theory instruction and technical support for the utilization of red mud with high iron content.