Separation and Purification Technology ( IF 8.6 ) Pub Date : 2021-04-30 , DOI: 10.1016/j.seppur.2021.118742 Yan Zhou , Jianxing Liu , Gongjin Cheng , Xiangxin Xue , He Yang
In this work, carbothermal reduction followed by sulfuric acid (H2SO4) leaching of Bayan Obo tailings has been studied for the selective concentration of Fe and rare earth (RE) minerals. The effect of basicity on the metallization rate of Fe, transfer behaviors of metallic Fe and RE elements, phase composition, and element migration was investigated using XRD, SEM-EDS, EDS mapping, and FT-IR spectroscopy. At a roasting temperature of 1100–1200 °C and a basicity of 1.87, more than 99% of Fe was metallized and 97.91% of Fe and 94.94% of RE were separated magnetically. After roasting, the RE elements mainly existed in Ca2RE8(SiO4)6O2 and Ca8RE2(PO4)6O2, 88% of which were leached out by H2SO4 at 25 °C with an initial concentration of 2 mol/L and a stirring speed of 900 r/min. The precipitation of RE2(SO4)3 was responsible for the incomplete recovery of RE elements during leaching.
中文翻译:
碳热还原,然后用Bayes Obo尾矿进行硫酸浸出以选择性地浓缩铁和稀土金属
在这项工作中,已经研究了碳热还原后再用Bayan Obo尾矿中的硫酸(H 2 SO 4)浸出的方法,以选择性地富集Fe和稀土(RE)矿物。使用XRD,SEM-EDS,EDS映射和FT-IR光谱研究了碱度对Fe的金属化速率,金属Fe和RE元素的转移行为,相组成以及元素迁移的影响。在1100-1200°C的焙烧温度和1.87的碱度下,超过99%的Fe被金属化,而97.91%的Fe和94.94%的RE被磁分离。焙烧后,稀土元素主要存在于Ca 2 RE 8(SiO 4)6 O 2和Ca 8中。RE 2(PO 4)6 O 2,其中的88%在25°C下被H 2 SO 4浸出,初始浓度为2 mol / L,搅拌速度为900 r / min。RE 2(SO 4)3的沉淀是浸出过程中RE元素回收不完全的原因。