The aim of this investigation was to prepare geopolymeric precursor from vanadium tailing(VT)by thermal activation and modification.For activation,a homogeneous blend of VT and sodium hydroxide was calcinated at an el...The aim of this investigation was to prepare geopolymeric precursor from vanadium tailing(VT)by thermal activation and modification.For activation,a homogeneous blend of VT and sodium hydroxide was calcinated at an elevated temperature and then modified with metakaolin to produce a geopolymeric precursor.During the thermal activation,the VT was corroded by sodium hydroxide and then sodium silicate formed on the particle surfaces.After water was added,the sodium silicate coating dissolved to release silicon species,which created an alkaline solution environment.The metakaolin then dissolved in the alkaline environment to generate aluminum species,which was followed by geopolymerization.The VT particles were connected by a gel produced during geopolymerization,which yielded a geopolymer with excellent mechanical performance.This investigation not only improves the feasibility of using geopolymer technology for large-scale and in-situ applications,but also promotes the utilization of VT and other silica-rich solid wastes.展开更多
Reduction roasting with sodium sulfate fol- lowed by magnetic separation was investigated to utilize vanadium tailings with total iron grade of 54.90 wt% and TiO2 content of 17.40 wt%. The results show that after redu...Reduction roasting with sodium sulfate fol- lowed by magnetic separation was investigated to utilize vanadium tailings with total iron grade of 54.90 wt% and TiO2 content of 17.40 wt%. The results show that after reduction roasting-magnetic separation with sodium sul- fate dosage of 2 wt% at roasting temperature of 1150℃ for roasting time of 120 min, metallic iron concentrate with total iron grade of 90.20 wt%, iron recovery rate of 97.56 % and TiO2 content of 4.85 wt% is obtained and high-titanium slag with TiO2 content of 57.31 wt% and TiO2 recovery rate of 80.27 % is also obtained. The results show that sodium sulfate has a catalytic effect on the reduction of tailings in the novel process by thermody- namics, scanning electron microscopy （SEM） and X-ray diffraction （XRD） and reacts with silica and alumina in the tailings to form sodium silicate and sodium aluminosili- cate. Migration of elements and chemical reactions destroy the crystal structures of minerals and promote the reduction of vanadium tailings, resulting in that iron grains grow to large size so that metallic iron concentrate with high total iron grade and low TiO2 content is obtained.展开更多
基金This work was financially supported by the Major Tech-nical Innovation Project of Hubei Province,China(No.2018ACA157)the National Natural Science Foundation of China(No.51874222)the Excellent Dissertation Cul-tivation Funds of Wuhan University of Technology(No.2018-YS-052).
文摘The aim of this investigation was to prepare geopolymeric precursor from vanadium tailing(VT)by thermal activation and modification.For activation,a homogeneous blend of VT and sodium hydroxide was calcinated at an elevated temperature and then modified with metakaolin to produce a geopolymeric precursor.During the thermal activation,the VT was corroded by sodium hydroxide and then sodium silicate formed on the particle surfaces.After water was added,the sodium silicate coating dissolved to release silicon species,which created an alkaline solution environment.The metakaolin then dissolved in the alkaline environment to generate aluminum species,which was followed by geopolymerization.The VT particles were connected by a gel produced during geopolymerization,which yielded a geopolymer with excellent mechanical performance.This investigation not only improves the feasibility of using geopolymer technology for large-scale and in-situ applications,but also promotes the utilization of VT and other silica-rich solid wastes.
基金financially supported by Fundamental Research Funds for the Central Universities (No. 2014zzts273)the National Professional Senior Researchers and Visiting Scholar Programs (No. [2013]3018)
文摘Reduction roasting with sodium sulfate fol- lowed by magnetic separation was investigated to utilize vanadium tailings with total iron grade of 54.90 wt% and TiO2 content of 17.40 wt%. The results show that after reduction roasting-magnetic separation with sodium sul- fate dosage of 2 wt% at roasting temperature of 1150℃ for roasting time of 120 min, metallic iron concentrate with total iron grade of 90.20 wt%, iron recovery rate of 97.56 % and TiO2 content of 4.85 wt% is obtained and high-titanium slag with TiO2 content of 57.31 wt% and TiO2 recovery rate of 80.27 % is also obtained. The results show that sodium sulfate has a catalytic effect on the reduction of tailings in the novel process by thermody- namics, scanning electron microscopy （SEM） and X-ray diffraction （XRD） and reacts with silica and alumina in the tailings to form sodium silicate and sodium aluminosili- cate. Migration of elements and chemical reactions destroy the crystal structures of minerals and promote the reduction of vanadium tailings, resulting in that iron grains grow to large size so that metallic iron concentrate with high total iron grade and low TiO2 content is obtained.
