The effect of conventional thermal pretreatment on the surface properties of ilmenite and its accompanied gangue minerals was investigated using flotation experiments(microflotation and laboratory cell flotation),XRD,...The effect of conventional thermal pretreatment on the surface properties of ilmenite and its accompanied gangue minerals was investigated using flotation experiments(microflotation and laboratory cell flotation),XRD,XPS and FT-IR analysis and zeta potential and contact angle measurements.After treatment at 600℃ for 25 min as optimal condition,the floatability of ilmenite is improved from 73.5%to 91%at a pH value of 6.3.As demonstrated by XRD and XPS analysis,under this pretreatment condition,the Fe^(3+)content increases by almost 16.5%without any phase decomposition and structural changes in ilmenite.FT-IR analysis and contact angle and zeta potential measurements give evidences that the improvement of ilmenite floatability can be related to the enhancement of collector adsorption and the formation of a more insoluble hydrophobic layer of ferric iron oleate.The ore flotation experiments show that the thermal pretreatment process without making a significant change in TiO2 content of ilmenite concentrate enhances the TiO2 recovery from 65.4%to 73.7%.展开更多
Experiments were conducted to investigate the behavior of the sequential system of intensified zero-valent iron process(IZVI) and anaerobic filter and biological aerated filter(AF/BAF) reactors for advanced treatment ...Experiments were conducted to investigate the behavior of the sequential system of intensified zero-valent iron process(IZVI) and anaerobic filter and biological aerated filter(AF/BAF) reactors for advanced treatment of biologically pretreated coking wastewater. Particular attention was paid to the performance of the integrated system for the removal of chemical oxygen demand(COD), ammonia nitrogen(NH3-N) and total nitrogen(TN). The average removal efficiencies of COD, NH3-N and TN were 76.28%, 96.76% and 59.97%, with the average effluent mass concentrations of 56, 0.53 and 18.83 mg/L, respectively, reaching the first grade of the national discharge standard. Moreover, the results of gas chromatography/mass spectrum(GC/MS) and gel permeation chromatography(GPC) analysis demonstrated that the refractory organic compounds with high relative molecular mass were partly removed in IZVI process by the function of oxidation-reduction, flocculation and adsorption which could also enhance the biodegradability of the system effluent. The removal efficiencies of NH3-N and TN were achieved mainly in the subsequent AF/BAF reactors by nitrification and denitrification. Overall, the results obtained show that the application of IZVI in combination with AF/BAF is a promising technology for advanced treatment of biologically pretreated coking wastewater.展开更多
文摘The effect of conventional thermal pretreatment on the surface properties of ilmenite and its accompanied gangue minerals was investigated using flotation experiments(microflotation and laboratory cell flotation),XRD,XPS and FT-IR analysis and zeta potential and contact angle measurements.After treatment at 600℃ for 25 min as optimal condition,the floatability of ilmenite is improved from 73.5%to 91%at a pH value of 6.3.As demonstrated by XRD and XPS analysis,under this pretreatment condition,the Fe^(3+)content increases by almost 16.5%without any phase decomposition and structural changes in ilmenite.FT-IR analysis and contact angle and zeta potential measurements give evidences that the improvement of ilmenite floatability can be related to the enhancement of collector adsorption and the formation of a more insoluble hydrophobic layer of ferric iron oleate.The ore flotation experiments show that the thermal pretreatment process without making a significant change in TiO2 content of ilmenite concentrate enhances the TiO2 recovery from 65.4%to 73.7%.
基金Project(2006BAJ04A)suppprted by the National Sci-Tech Support Plan,China
文摘Experiments were conducted to investigate the behavior of the sequential system of intensified zero-valent iron process(IZVI) and anaerobic filter and biological aerated filter(AF/BAF) reactors for advanced treatment of biologically pretreated coking wastewater. Particular attention was paid to the performance of the integrated system for the removal of chemical oxygen demand(COD), ammonia nitrogen(NH3-N) and total nitrogen(TN). The average removal efficiencies of COD, NH3-N and TN were 76.28%, 96.76% and 59.97%, with the average effluent mass concentrations of 56, 0.53 and 18.83 mg/L, respectively, reaching the first grade of the national discharge standard. Moreover, the results of gas chromatography/mass spectrum(GC/MS) and gel permeation chromatography(GPC) analysis demonstrated that the refractory organic compounds with high relative molecular mass were partly removed in IZVI process by the function of oxidation-reduction, flocculation and adsorption which could also enhance the biodegradability of the system effluent. The removal efficiencies of NH3-N and TN were achieved mainly in the subsequent AF/BAF reactors by nitrification and denitrification. Overall, the results obtained show that the application of IZVI in combination with AF/BAF is a promising technology for advanced treatment of biologically pretreated coking wastewater.
