基于直接还原的高铁铝土矿选择性富集

胡文韬¹，王化军¹，季春伶¹，孙传尧^{1, 2}，于宏东²，张云海²

(1. 北京科技大学 土木与环境工程学院，金属矿山高效开采与安全教育部重点实验室，北京，100083；
2. 北京矿冶研究总院 矿物加工科学与技术国家重点实验室，北京，100070)

摘 要：研究还原剂用量、保温温度、保温时间、升温速率和降温速率对高铁铝土矿组分选择性富集以及刚玉晶体长大的影响。研究结果表明：还原气氛中赤铁矿被还原为单质铁后富集于金属相，水铝石转化为α-Al₂O₃富集于刚玉相；高岭石转化为莫来石和非晶SiO₂富集于硅酸盐相；增加保温时间可以有效促进刚玉晶粒的长大和粗化而不会出现粒铁和金属夹渣现象；采用直接还原方案可以实现高铁铝土矿中组分的选择性富集。

关键词：铝土矿；铁；氧化铝；刚玉；直接还原

Selective enrichment of ferric bauxite based on direct-reduction process

HU Wen-tao¹, WANG Hua-jun¹, JI Chun-ling¹, SUN Chuan-yao^{1, 2}, YU Hong-dong², ZHANG Yun-hai²

(1. Key Laboratory of High Efficiency Mining and Safety for Metal Mines, Ministry of Education,
School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing 100083, China;
2. State Key Laboratory of Mineral Processing Science and Technology,
Beijing General Research Institute of mining & Metallurgy, Beijing 100070, China)

Abstract:The effects of various factors, such as reduction coal dosage, preservation temperature, preservation time, and heating rate, on selective enrichment of useful constituents in ferric bauxite and the growth of corundum crystallite were investigated. The results show that the iron oxide in ferric bauxite is reduced into iron and accumulated in metallic phase. Diaspore and boehmite are converted into α-Al₂O₃ and enriched in corundum phase. Kaolin is converted into mullite and non-crystalline SiO₂ and accumulated in aluminosilicate phase. The growth and coarsening of corundum grain are promoted by the increase of the preservation temperature. After reduction, no luppen or slag inclusion is found in clinker. It is found that selective enrichment of useful constituents can be realized by direct-reduction process.

Key words:bauxite; iron; alumina; corundum; direct reduction