Selective separation of iron and scandium from Bayer Sc-bearing red mud  

作　　者：Junhui Xiao Kai Zou Nanlan Zhong Deqiang Gao 

机构地区：[1]Sichuan Provincial Engineering Lab of Nonmetallic Mineral Powder Modification and High-Value Utilization,Southwest University of Science and Technology,Mianyang 621010,China [2]Dongfang Boiler Group Co.,Ltd.,Zigong 643001,China [3]Key Laboratory of Ministry of Education for Solid Waste Treatment and Resource Recycle,Southwest University of Science and Technology,Mianyang 621010,China

出　　处：《Journal of Rare Earths》2023年第7期1099-1107,I0005,共10页稀土学报（英文版）

基　　金：Project supported by the Sichuan Science and Technology Program(2022YFS0462,2021YJ0057,2021YFG0268);the China Postdoctoral Science Foundation(2014M560734)。

摘　　要：In this study,we investigated the separation of iron and scandium from Sc-bearing red mud.The red mud object of our study contained 31.11 wt%total iron(TFe),0.0045 wt%Sc,hematite(Fe_(2)O_(3))and ferrosilite(FeO·SiO_(2))as the main Fe-bearing minerals.The Sc-bearing red mud was treated by a novel deep reduction roasting and magnetic separation process that includes the addition of coke and CaO to extract Fe and enriching Sc from the Sc-bearing red mud.The addition of coke and CaO enhances the transformation of hematite(Fe_(2)O_(3))to metallic iron(Fe~0)and magnetite(Fe_(3)O_(4))as well as the transformation of ferrosilite into metallic iron(Fe~0).The test results show that utilizing the new process a Fe concentrate with a TFe content of 81.22 wt%and Fe recovery of 92.96%was obtained.Furthermore,magnetic separation tailings with Sc content of 0.0062 wt%and Sc recovery of 98.65%were also obtained.The test results were achieved under the following process conditions:roasting temperature of 1373 K,roasting time of 45 min,calcium oxide dosage of 20 wt%,coke dosage of 25 wt%,grinding fineness of90%<0.04 mm,and magnetic field intensity of 0.24 T.The major minerals in the Fe concentrate are metallic iron(Fe~0)and magnetite(Fe_(3)O_(4)).The main minerals in the magnetic separation tailings with a low TFe content of 2.62%are CaO·SiO_(2),Na_(2)O·SiO_(2),FeO·SiO_(2),Ca_(3)Fe_(2)Si_(3)O_(12),CaAl_(2)SiO_6 and CaFe(SiO_(3))_(2).

关 键 词：Red mud SCANDIUM IRON Deep reduction roasting Magnetic separation Rare earths 

分 类 号：X758[环境科学与工程—环境工程]