Nanostructured Fe-doped titanium dioxide was synthesized from titanium containing electric furnace molten slag(TCEFMS)by using an alkali fusion,followed by a hydrolyzation-acidolysis-calcination route.The efects of al...Nanostructured Fe-doped titanium dioxide was synthesized from titanium containing electric furnace molten slag(TCEFMS)by using an alkali fusion,followed by a hydrolyzation-acidolysis-calcination route.The efects of alkali/slag mass ratio,calcinating temperature,calcinating time,and water/slag mass ratio on the extraction efciency and purity of products were systematically studied in this paper.It is indicated that the best extraction efciency of nanostructured Fedoped titanium dioxide is 99.35%,when the molten slag is calcinated at 700 C for 1 h with the mass ratio of alkali/molten slag of 1.5:1.The influence of alkali/slag mass ratio on the photocatalytic activity of final products was evaluated by the photodegradation of methyl blue under visible light irradiation.A maximum photodegradation efciency of 88.12%over30 min was achieved under the optimum conditions.展开更多
Extraction and separation of nickel and cobalt from saprolite laterite ore were studied by using a method of microwave-assisted hydrothermal leaching and chemical deposition. The effects of leaching temperature and ti...Extraction and separation of nickel and cobalt from saprolite laterite ore were studied by using a method of microwave-assisted hydrothermal leaching and chemical deposition. The effects of leaching temperature and time on the extraction efficiencies of Ni2+ and Co2+ were investigated in detail under microwave conditions. It is shown that the extraction efficiencies of Ni2+ and Co2+ from the ore pre-roasted at 300 C for 5 h were 89.19% and 61.89% when the leaching temperature and time were about 70 C and 60 min, respectively. For the separation process of Ni and Co, the separation of main chemical components was performed by adjusting the pH values of sulfuric leaching solutions using a NaOH solution based on the different pH values of precipitation for metal hydroxides. The final separation efficiencies of Ni and Co were 77.29% and 65.87%, respectively. Furthermore, the separation efficiencies of Fe of 95.36% and Mg of 92.2% were also achieved at the same time.展开更多
Effects of the weld microstructure and inclusions on brittle fracture initiation are investigated in a thermally aged ferritic high-nickel weld of a reactor pressure vessel head from a decommissioned nuclear power pla...Effects of the weld microstructure and inclusions on brittle fracture initiation are investigated in a thermally aged ferritic high-nickel weld of a reactor pressure vessel head from a decommissioned nuclear power plant.As-welded and reheated regions mainly consist of acicular and polygonal ferrite,respectively.Fractographic examination of Charpy V-notch impact toughness specimens reveals large inclusions(0.5-2.5μm)at the brittle fracture primary initiation sites.High impact energies were measured for the specimens in which brittle fracture was initiated from a small inclusion or an inclusion away from the V-notch.The density,geometry,and chemical composition of the primary initiation inclusions were investigated.A brittle fracture crack initiates as a microcrack either within the multiphase oxide inclusions or from the debonded interfaces between the uncracked inclusions and weld metal matrix.Primary fracture sites can be determined in all the specimens tested in the lower part of the transition curve at and below the 41-J reference impact toughness energy but not above the mentioned value because of the changes in the fracture mechanism and resulting changes in the fracture appearance.展开更多
Nanostructured TiO2 with different morphologies and crystal phases was successfully synthesized from titanium-containing electric furnace molten slag by using a hydrothermal method followed by reflux process in acid s...Nanostructured TiO2 with different morphologies and crystal phases was successfully synthesized from titanium-containing electric furnace molten slag by using a hydrothermal method followed by reflux process in acid solution. The effects of acid concentration, reflux time, and acid type on the formation of TiO2 were systematically investigated by scanning electron microscopy, X-ray diffraction(XRD), transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM),and X-ray fluorescence(XRF). It is indicated that TiO2 nanorod with rutile phase is achieved in nitric or hydrochloric acid, while anatase TiO2 nanodisk is formed in sulfuric acid.With the increase of the concentration of hydrochloric acid from 0.3 to 1.5 mol L-1, the dispersibility and crystallinity of the final product can be improved. With prolonging the reflux time from 6 to 14 h, the rutile TiO2 nanorod with uniform crystal size and high crystallinity is obtained. The growth mechanism of TiO2 nanorod and nanodisk prepared under different conditions was also discussed.展开更多
基金supported by the National Nature Science Foundation of China(Nos.51272025,50872011,and 50672006)the Major State Basic Research and Development Program of China(No.2007CB613608)
文摘Nanostructured Fe-doped titanium dioxide was synthesized from titanium containing electric furnace molten slag(TCEFMS)by using an alkali fusion,followed by a hydrolyzation-acidolysis-calcination route.The efects of alkali/slag mass ratio,calcinating temperature,calcinating time,and water/slag mass ratio on the extraction efciency and purity of products were systematically studied in this paper.It is indicated that the best extraction efciency of nanostructured Fedoped titanium dioxide is 99.35%,when the molten slag is calcinated at 700 C for 1 h with the mass ratio of alkali/molten slag of 1.5:1.The influence of alkali/slag mass ratio on the photocatalytic activity of final products was evaluated by the photodegradation of methyl blue under visible light irradiation.A maximum photodegradation efciency of 88.12%over30 min was achieved under the optimum conditions.
基金financially supported by the National Natural Science Foundation of China(Nos. 51272025,50872011 and 51072022)the National Basic Research Program of China(No. 2007CB613608)the New Century Excellent Researcher Award Program from the Ministry of Education of China (No. NCET-08-0732)
文摘Extraction and separation of nickel and cobalt from saprolite laterite ore were studied by using a method of microwave-assisted hydrothermal leaching and chemical deposition. The effects of leaching temperature and time on the extraction efficiencies of Ni2+ and Co2+ were investigated in detail under microwave conditions. It is shown that the extraction efficiencies of Ni2+ and Co2+ from the ore pre-roasted at 300 C for 5 h were 89.19% and 61.89% when the leaching temperature and time were about 70 C and 60 min, respectively. For the separation process of Ni and Co, the separation of main chemical components was performed by adjusting the pH values of sulfuric leaching solutions using a NaOH solution based on the different pH values of precipitation for metal hydroxides. The final separation efficiencies of Ni and Co were 77.29% and 65.87%, respectively. Furthermore, the separation efficiencies of Fe of 95.36% and Mg of 92.2% were also achieved at the same time.
基金the SAFIR2022 BRUTE project (Barseback RPV material used for true evaluation of embrittlement) for funding the study
文摘Effects of the weld microstructure and inclusions on brittle fracture initiation are investigated in a thermally aged ferritic high-nickel weld of a reactor pressure vessel head from a decommissioned nuclear power plant.As-welded and reheated regions mainly consist of acicular and polygonal ferrite,respectively.Fractographic examination of Charpy V-notch impact toughness specimens reveals large inclusions(0.5-2.5μm)at the brittle fracture primary initiation sites.High impact energies were measured for the specimens in which brittle fracture was initiated from a small inclusion or an inclusion away from the V-notch.The density,geometry,and chemical composition of the primary initiation inclusions were investigated.A brittle fracture crack initiates as a microcrack either within the multiphase oxide inclusions or from the debonded interfaces between the uncracked inclusions and weld metal matrix.Primary fracture sites can be determined in all the specimens tested in the lower part of the transition curve at and below the 41-J reference impact toughness energy but not above the mentioned value because of the changes in the fracture mechanism and resulting changes in the fracture appearance.
基金financially supported by the National Natural Science Foundation of China(Nos.51272025 and 51072022)the State Basic Research Development Program of China(973 Program)(No.2007CB613608)the New Century Excellent Researcher Award Program from Ministry of Education of China(No.NCET-08-0732)
文摘Nanostructured TiO2 with different morphologies and crystal phases was successfully synthesized from titanium-containing electric furnace molten slag by using a hydrothermal method followed by reflux process in acid solution. The effects of acid concentration, reflux time, and acid type on the formation of TiO2 were systematically investigated by scanning electron microscopy, X-ray diffraction(XRD), transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM),and X-ray fluorescence(XRF). It is indicated that TiO2 nanorod with rutile phase is achieved in nitric or hydrochloric acid, while anatase TiO2 nanodisk is formed in sulfuric acid.With the increase of the concentration of hydrochloric acid from 0.3 to 1.5 mol L-1, the dispersibility and crystallinity of the final product can be improved. With prolonging the reflux time from 6 to 14 h, the rutile TiO2 nanorod with uniform crystal size and high crystallinity is obtained. The growth mechanism of TiO2 nanorod and nanodisk prepared under different conditions was also discussed.