The storage of solid waste in Bayan Obo has resulted in significant resource wastage and environmental concerns.In this study,an efficient process was developed to recover iron and rare earth elements(REEs)from this w...The storage of solid waste in Bayan Obo has resulted in significant resource wastage and environmental concerns.In this study,an efficient process was developed to recover iron and rare earth elements(REEs)from this waste by processes of hydrogen-based mineral phase transformation(HMPT),magnetic separation,and flotation.Under optimal HMPT conditions(525℃,12.5 min,and 30%H_(2)concentration),an iron concentrate with a TFe grade of 64.09%and a recovery of 95.33%was obtained.The magnetic properties of the solid waste were greatly enhanced by HMPT,allowing the effective magnetic separation of iron minerals.Further optimization of the flotation process resulted in a REEs concentrate with a rare earth oxide(REO)grade of 65%-70%and a REEs recovery of 60%-65%.Hematite was reduced to magnetite during HMPT,and bastnaesite was decomposed to REEs oxides and fluorides,and the particle structure was significantly destroyed.However,changes in monazite,fluorite,and barite were minimal.展开更多
Pretreatment of high content of Si- and Al-containing cyanide tailings by water leaching to remove some impurities, such as the major impurities minerals of Si and A1, as well as its effect on Fe extraction in the wat...Pretreatment of high content of Si- and Al-containing cyanide tailings by water leaching to remove some impurities, such as the major impurities minerals of Si and A1, as well as its effect on Fe extraction in the water leaching process was investigated. The effects of different parameters on iron recovery were studied, and the reaction parameters were proposed as follows： sodium carbonate content of 30%, water leaching at 60 ~C for 5 min, liquid/solid ratio of 15：1, and exciting current of 2 A. Under these optimal conditions, magnetic concentrate containing 59.11% total iron and a total iron recovery rate of 76.12% was obtained. In addition, the microstructure and phase transformation of the process of water leaching were studied by X-ray powder diffraction technique （XRD）, Electronic image of backscattering （BEI）, X-ray fluorescence （XRF）, and energy dispersive spectrometry （EDS）. The results indicate that the soluble compound impurities generated in the roasting process are washed out, and the dissoluble substances enter into nonmagnetic materials by water leaching, realizing the effective separation of impurities and Fe.展开更多
基金supported by the National Key R&D Program of China(No.2021YFC2901000)the Key Program of National Natural Science Foundation of China(No.52130406)+1 种基金the Natural Science Foundation Innovation Group Project of Hubei Province(No.2023AFA044)the Fundamental Research Funds for the Central Universities(No.N2301002)。
文摘The storage of solid waste in Bayan Obo has resulted in significant resource wastage and environmental concerns.In this study,an efficient process was developed to recover iron and rare earth elements(REEs)from this waste by processes of hydrogen-based mineral phase transformation(HMPT),magnetic separation,and flotation.Under optimal HMPT conditions(525℃,12.5 min,and 30%H_(2)concentration),an iron concentrate with a TFe grade of 64.09%and a recovery of 95.33%was obtained.The magnetic properties of the solid waste were greatly enhanced by HMPT,allowing the effective magnetic separation of iron minerals.Further optimization of the flotation process resulted in a REEs concentrate with a rare earth oxide(REO)grade of 65%-70%and a REEs recovery of 60%-65%.Hematite was reduced to magnetite during HMPT,and bastnaesite was decomposed to REEs oxides and fluorides,and the particle structure was significantly destroyed.However,changes in monazite,fluorite,and barite were minimal.
基金Projects(ZR2010EL006,Y2007F60) supported by the National Science Foundation of Shandong Province of ChinaProject(J12LA04) supported by High Education Science Technology Program of Shandong Province,China
文摘Pretreatment of high content of Si- and Al-containing cyanide tailings by water leaching to remove some impurities, such as the major impurities minerals of Si and A1, as well as its effect on Fe extraction in the water leaching process was investigated. The effects of different parameters on iron recovery were studied, and the reaction parameters were proposed as follows： sodium carbonate content of 30%, water leaching at 60 ~C for 5 min, liquid/solid ratio of 15：1, and exciting current of 2 A. Under these optimal conditions, magnetic concentrate containing 59.11% total iron and a total iron recovery rate of 76.12% was obtained. In addition, the microstructure and phase transformation of the process of water leaching were studied by X-ray powder diffraction technique （XRD）, Electronic image of backscattering （BEI）, X-ray fluorescence （XRF）, and energy dispersive spectrometry （EDS）. The results indicate that the soluble compound impurities generated in the roasting process are washed out, and the dissoluble substances enter into nonmagnetic materials by water leaching, realizing the effective separation of impurities and Fe.
