A novel method of pellet calcification roasting-H_(2)SO_(4) leaching was proposed to efficiently separate and extract vanadium(V)from vanadium-titanium(V-Ti)magnetite concentrates.The leaching rate of V is as high as ...A novel method of pellet calcification roasting-H_(2)SO_(4) leaching was proposed to efficiently separate and extract vanadium(V)from vanadium-titanium(V-Ti)magnetite concentrates.The leaching rate of V is as high as 88.98%,while the leaching rate of impurity iron is only 1.79%.Moreover,the leached pellets can be used as raw materials for blast furnace ironmaking after secondary roasting.X-ray photoelectron spectroscopy(XPS)and scanning electron microscopy with energy dispersive X-ray spectrometry(SEMEDS)analyses showed that V^(3+)was oxidized to V^(5+)after roasting at 1200℃,and V^(5+)was then leached by H_(2)SO_(4).X-ray diffraction(XRD)analyses and single factor experiment revealed a minimal amount of dissolved Fe_(2)O_(3) during H_(2)SO_(4) leaching.Therefore,a high separation degree of V and iron(Fe)from V-Ti magnetite concentrate was achieved through H_(2)SO_(4) leaching.Compared with the traditional roastingleaching process,this process can achieve a high selectivity of V and Fe,and has excellent prospects for industrial production.展开更多
Pilot experiments on Na;SO;-roasting of V-Ti magnetite(VTM) concentrate pellets were performed to activate vanadium with simulated grate-kiln machines. Combined with thermodynamic calculation, X-ray diffraction(XRD), ...Pilot experiments on Na;SO;-roasting of V-Ti magnetite(VTM) concentrate pellets were performed to activate vanadium with simulated grate-kiln machines. Combined with thermodynamic calculation, X-ray diffraction(XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy(SEM-EDS), and inductively coupled plasma-atomic emission spectrometry(ICP-AES) analyses, process parameters of pellet making were optimized, and the enhancement of vanadium oxidation and conversion was realized. The results show that, in balling stage, adding Na;SO;can promote the thermal decrepitation resistance of green pellets;in the drying stage, higher wind temperature can improve the dispersion of sodium salt in pellets;in preheating stage, using O;-rich hot gas can promote more thorough oxidation of vanadium;in roasting stage, the effect of vanadium conversion to sodium vanadate is better when the liquid amount is 15.5%-22.5%. Based on the above measures, the vanadium conversion rate achieved in the roasted pellets is 85.6%, proving the feasibility of vanadium recovery using an existing pellet production line.展开更多
Objective In recent years, the birth time and evolution of the Three Gorges, Yangtze River has become a focused topic. Different from previous studies, this study used provenance analysis of Quaternary sediments to di...Objective In recent years, the birth time and evolution of the Three Gorges, Yangtze River has become a focused topic. Different from previous studies, this study used provenance analysis of Quaternary sediments to discuss this question. Among those minerals in Quaternary sediments, magnetite was rarely studied. This paper presents element geochemistry and backscatter images of detrital magnetites from the Quaternary sediments in the Yichang area of Hubei Province. By discussing the provenance changes of detratic magnetites, we suggested the birth time of the Three Gorges of the Yangtze River.展开更多
条带状铁建造(banded iron formation,BIF)是前寒武纪地层中广泛发育的一类富铁沉积岩,它在华北克拉通内广泛发育。在华北克拉通南缘的舞阳地区,晚太古代太华群铁山庙组BIF包含石英-磁铁矿和辉石-磁铁矿两种组合,前者的绝大部分磁铁矿...条带状铁建造(banded iron formation,BIF)是前寒武纪地层中广泛发育的一类富铁沉积岩,它在华北克拉通内广泛发育。在华北克拉通南缘的舞阳地区,晚太古代太华群铁山庙组BIF包含石英-磁铁矿和辉石-磁铁矿两种组合,前者的绝大部分磁铁矿颗粒均自形程度高、粒度粗大并常常紧密伴生有一定量的方解石。舞阳地区铁山庙组BIF的RAMAN,SEM,CL和EDS分析结果表明:石英-磁铁矿矿石中的磁铁矿自形程度最高、石英次之、方解石最低;方解石似条带的RAMAN分析结果指示其有序度、结晶程度沿条带的垂直方向无规律突变,明显不同于裂隙中后期热液流体沉淀形成的方解石脉;方解石发生了塑性流变并最终定位于石英和磁铁矿间的间隙内,其矿物的截面形状和展布特征明显受控于石英和磁铁矿并得到了石英颗粒间微裂隙内方解石的证实;方解石似条带的微区成份存在明显差异,这反映方解石经历了塑性流变及再次汇聚;在磁铁矿颗粒的汇聚及生长过程中,方解石充当了磁铁矿微颗粒迁移的媒介并得到了方解石中磁铁矿微颗粒局部富集现象的证实。展开更多
基金funded by the National Science Foundation of China(No.51704028)the Key R&D Program of Yunnan Province(No.2018IB027)。
文摘A novel method of pellet calcification roasting-H_(2)SO_(4) leaching was proposed to efficiently separate and extract vanadium(V)from vanadium-titanium(V-Ti)magnetite concentrates.The leaching rate of V is as high as 88.98%,while the leaching rate of impurity iron is only 1.79%.Moreover,the leached pellets can be used as raw materials for blast furnace ironmaking after secondary roasting.X-ray photoelectron spectroscopy(XPS)and scanning electron microscopy with energy dispersive X-ray spectrometry(SEMEDS)analyses showed that V^(3+)was oxidized to V^(5+)after roasting at 1200℃,and V^(5+)was then leached by H_(2)SO_(4).X-ray diffraction(XRD)analyses and single factor experiment revealed a minimal amount of dissolved Fe_(2)O_(3) during H_(2)SO_(4) leaching.Therefore,a high separation degree of V and iron(Fe)from V-Ti magnetite concentrate was achieved through H_(2)SO_(4) leaching.Compared with the traditional roastingleaching process,this process can achieve a high selectivity of V and Fe,and has excellent prospects for industrial production.
基金financially supported by the Science and Technology Innovation Program of Hunan Province, China (No. 2021RC2003)the National Natural Science Foundation of China (No. 72088101)China Postdoctoral Science Foundation (No. 2021TQ0370)。
文摘Pilot experiments on Na;SO;-roasting of V-Ti magnetite(VTM) concentrate pellets were performed to activate vanadium with simulated grate-kiln machines. Combined with thermodynamic calculation, X-ray diffraction(XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy(SEM-EDS), and inductively coupled plasma-atomic emission spectrometry(ICP-AES) analyses, process parameters of pellet making were optimized, and the enhancement of vanadium oxidation and conversion was realized. The results show that, in balling stage, adding Na;SO;can promote the thermal decrepitation resistance of green pellets;in the drying stage, higher wind temperature can improve the dispersion of sodium salt in pellets;in preheating stage, using O;-rich hot gas can promote more thorough oxidation of vanadium;in roasting stage, the effect of vanadium conversion to sodium vanadate is better when the liquid amount is 15.5%-22.5%. Based on the above measures, the vanadium conversion rate achieved in the roasted pellets is 85.6%, proving the feasibility of vanadium recovery using an existing pellet production line.
基金financially supported by the National Natural Science Foundation of China (grants No.41072083 and 4157209)
文摘Objective In recent years, the birth time and evolution of the Three Gorges, Yangtze River has become a focused topic. Different from previous studies, this study used provenance analysis of Quaternary sediments to discuss this question. Among those minerals in Quaternary sediments, magnetite was rarely studied. This paper presents element geochemistry and backscatter images of detrital magnetites from the Quaternary sediments in the Yichang area of Hubei Province. By discussing the provenance changes of detratic magnetites, we suggested the birth time of the Three Gorges of the Yangtze River.
文摘条带状铁建造(banded iron formation,BIF)是前寒武纪地层中广泛发育的一类富铁沉积岩,它在华北克拉通内广泛发育。在华北克拉通南缘的舞阳地区,晚太古代太华群铁山庙组BIF包含石英-磁铁矿和辉石-磁铁矿两种组合,前者的绝大部分磁铁矿颗粒均自形程度高、粒度粗大并常常紧密伴生有一定量的方解石。舞阳地区铁山庙组BIF的RAMAN,SEM,CL和EDS分析结果表明:石英-磁铁矿矿石中的磁铁矿自形程度最高、石英次之、方解石最低;方解石似条带的RAMAN分析结果指示其有序度、结晶程度沿条带的垂直方向无规律突变,明显不同于裂隙中后期热液流体沉淀形成的方解石脉;方解石发生了塑性流变并最终定位于石英和磁铁矿间的间隙内,其矿物的截面形状和展布特征明显受控于石英和磁铁矿并得到了石英颗粒间微裂隙内方解石的证实;方解石似条带的微区成份存在明显差异,这反映方解石经历了塑性流变及再次汇聚;在磁铁矿颗粒的汇聚及生长过程中,方解石充当了磁铁矿微颗粒迁移的媒介并得到了方解石中磁铁矿微颗粒局部富集现象的证实。
