The carbothermic reduction of Panzhihua ilmenite with various additions of activated carbon was investigated byisothermal experiments over the temperature range of1373to1773K in the argon atmosphere.According to the r...The carbothermic reduction of Panzhihua ilmenite with various additions of activated carbon was investigated byisothermal experiments over the temperature range of1373to1773K in the argon atmosphere.According to the reaction kineticsrecorded by the infrared gas analyzer,it was found that the amount of carbon addition had little influence on the reaction rates atvarious temperatures except1473K.When the reaction temperature was above the eutectic temperature of1427K of Fe?C binarysystem,part of carbon would dissolve into Fe to form a liquid phase,which made the liquid Fe as a diffusion channel of carbon todiffuse to the reaction interface.The carbothermic reduction above1573K obeyed the shrinking-core model.The mass fraction ofTiC could be determined by the standard addition technique.展开更多
Thermally activated pinecone(TAP) was used for the adsorption of dimethyl trisulfide(DMTS)from aqueous solutions,which was proved to be the main odorous in algae-caused black bloom.The effects of adsorbent dosage,adso...Thermally activated pinecone(TAP) was used for the adsorption of dimethyl trisulfide(DMTS)from aqueous solutions,which was proved to be the main odorous in algae-caused black bloom.The effects of adsorbent dosage,adsorbate concentration and contact time on DMTS biosorption were studied.The TAP produced at 600℃ exhibited a relatively high surface area(519.69 m^2/g) and excellent adsorption capacity.The results show that the adsorption of DMTS was initially fast and that the equilibrium time was6 h.Higher initial DMTS concentrations led to lower removal percentages but higher adsorption capacity.The removal percentage of DMTS increased and the adsorption capacity of TAP decreased with an increase in adsorbent dosage.The adsorption process conforms well to a pseudo-second-order kinetics model.The adsorption of DMTS is more appropriately described by the Freundlich isotherm(R^2=0.996 1) than by the Langmuir isotherm(R^2=0.916 9).The results demonstrate that TAP could be an attractive low-cost adsorbent for removing DMTS from water.展开更多
The adsorption capability of D318 resin for Cr(Ⅵ) was investigated by chemistry analysis. Experimental results show that D318 resin has the best adsorption ability for Cr(Ⅵ) at pH=3.16 in HAc-NaAc medium. The st...The adsorption capability of D318 resin for Cr(Ⅵ) was investigated by chemistry analysis. Experimental results show that D318 resin has the best adsorption ability for Cr(Ⅵ) at pH=3.16 in HAc-NaAc medium. The statically saturated adsorption capacity of the resin is 265.4 mg/g. The thermodynamic adsorption parameters, enthalpy change AH and free energy change AG298 of the adsorption reaction are 4.81 and -5.16 kJ/mol, respectively. The apparent activation energy Ea is 22.4 kJ/mol. The adsorption behavior obeys the Freundlich isotherm. The molar coordination ratio of the functional group of resin to Cr(Ⅵ) is 3:2. Cr(Ⅵ) adsorbed on D318 resin can be eluted by 5%NaOH-5%NaCl quantitatively.展开更多
Rare-earth dements (REE) in limestones were measured by ICP-MS from the Yangdi section across the Frasnian-Famennian (F-F) transition in Guilin, Guangxi of South China. The average EREE contents of measured sample...Rare-earth dements (REE) in limestones were measured by ICP-MS from the Yangdi section across the Frasnian-Famennian (F-F) transition in Guilin, Guangxi of South China. The average EREE contents of measured samples are 33.32 ppm. The average LREE/HREE ratio is 6.35. Data show LREE-enriched REE distribution pattern in the Yangdi section. Most of samples are characterized by positive Eu anomaly with average of 1.13, and there are two maxima of Eu anomaly just below the F-F boundary. Almost all analytical samples show obvious tetrad effects. Remarkable M-shaped tetrad effects are observed in these samples with positive Eu anomaly. The characters of REE and some relative elements (Fe, Mn, Al, etc.) indicate that hydro- thermal activities occurred and resulted in seawater acidification in Upper and Lower Kellwasser horizons of the Late Devonian. The changes of marine environment caused by hydrothermal activities, such as seawater acidification, heavy metal pollution, and eutrophication, would destroy the neritic ecosystem and finally result in the F-F mass extinction.展开更多
Lithologically, two kinds of chert can be recognized in the Middle-Upper Permian from the Tieqiao section in Laibin area, Guangxi, i.e., calcic chert occurring mainly in the Maokou Formation and pure chert mainly in t...Lithologically, two kinds of chert can be recognized in the Middle-Upper Permian from the Tieqiao section in Laibin area, Guangxi, i.e., calcic chert occurring mainly in the Maokou Formation and pure chert mainly in the Wujiaping Formation. Geochemical data show that both kinds of chert contain very low A1203 (0-0.23%) and TiO2 (0.001%-0.024%) and low ZREE (0.55-19.94 ppm, averaging 9.97 ppm), as well as high ratio of Fe2O3/TiO2 (17-443, averaging 111) and low ratio of A1203/(Al2O3+Fe203) (0-0.26, averaging 0.09). Given that the average value Ce anomalies in chert deposited in the ridge-proximal environment is about 0.29, and that in the pelagic environment is about 0.60, the low Ce anomalies in the Tieqiao chert (0.24-0.46, averaging 0.35) imply that they were deposited in an ocean basin with influence of submarine hydrothermal fluid and no input of terrigenous materials. The vertical variation of the silica abundance in strata (SAIS) in the Middle-Upper Permian strata, together with the Eu anomalies and the ratios of ∑REE/Fe, indicates a relationship between the hydrothermal activity and the Emeishan basalt eruption, and that submarine hydrothermal activity was stronger in the Upper Permian (the Wujiapingian Stage) than in the Middle Permian (the Maokou Stage).展开更多
基金Project(FRF-TP-15-009A3) supported by the Fundamental Research Funds for the Central Universities,ChinaProject(U1460201) supported by the National Natural Science Foundation of China
文摘The carbothermic reduction of Panzhihua ilmenite with various additions of activated carbon was investigated byisothermal experiments over the temperature range of1373to1773K in the argon atmosphere.According to the reaction kineticsrecorded by the infrared gas analyzer,it was found that the amount of carbon addition had little influence on the reaction rates atvarious temperatures except1473K.When the reaction temperature was above the eutectic temperature of1427K of Fe?C binarysystem,part of carbon would dissolve into Fe to form a liquid phase,which made the liquid Fe as a diffusion channel of carbon todiffuse to the reaction interface.The carbothermic reduction above1573K obeyed the shrinking-core model.The mass fraction ofTiC could be determined by the standard addition technique.
基金Supported by the Taihu Special Project of Water Pollution Control,Jiangsu Province(No.TH2013214)the National Water Pollution Control and Management Technology Major Project(No.2012ZX07103-005)+1 种基金the Industry-Academia Cooperation Innovation Fund Project of Jiangsu Province(No.BY2011165)the Open Foundation of State Key Laboratory of Lake Science and Environment,CAS(No.2014SKL005)
文摘Thermally activated pinecone(TAP) was used for the adsorption of dimethyl trisulfide(DMTS)from aqueous solutions,which was proved to be the main odorous in algae-caused black bloom.The effects of adsorbent dosage,adsorbate concentration and contact time on DMTS biosorption were studied.The TAP produced at 600℃ exhibited a relatively high surface area(519.69 m^2/g) and excellent adsorption capacity.The results show that the adsorption of DMTS was initially fast and that the equilibrium time was6 h.Higher initial DMTS concentrations led to lower removal percentages but higher adsorption capacity.The removal percentage of DMTS increased and the adsorption capacity of TAP decreased with an increase in adsorbent dosage.The adsorption process conforms well to a pseudo-second-order kinetics model.The adsorption of DMTS is more appropriately described by the Freundlich isotherm(R^2=0.996 1) than by the Langmuir isotherm(R^2=0.916 9).The results demonstrate that TAP could be an attractive low-cost adsorbent for removing DMTS from water.
基金Project (Y304121) supported by the Natural Science Foundation of Zhejiang Province,China
文摘The adsorption capability of D318 resin for Cr(Ⅵ) was investigated by chemistry analysis. Experimental results show that D318 resin has the best adsorption ability for Cr(Ⅵ) at pH=3.16 in HAc-NaAc medium. The statically saturated adsorption capacity of the resin is 265.4 mg/g. The thermodynamic adsorption parameters, enthalpy change AH and free energy change AG298 of the adsorption reaction are 4.81 and -5.16 kJ/mol, respectively. The apparent activation energy Ea is 22.4 kJ/mol. The adsorption behavior obeys the Freundlich isotherm. The molar coordination ratio of the functional group of resin to Cr(Ⅵ) is 3:2. Cr(Ⅵ) adsorbed on D318 resin can be eluted by 5%NaOH-5%NaCl quantitatively.
基金supported by Natural Science Foundation of China(Grant Nos.40730209,40802005,40872001,40921062)the"111" Project(Grant No.B08030)the MOST Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources
文摘Rare-earth dements (REE) in limestones were measured by ICP-MS from the Yangdi section across the Frasnian-Famennian (F-F) transition in Guilin, Guangxi of South China. The average EREE contents of measured samples are 33.32 ppm. The average LREE/HREE ratio is 6.35. Data show LREE-enriched REE distribution pattern in the Yangdi section. Most of samples are characterized by positive Eu anomaly with average of 1.13, and there are two maxima of Eu anomaly just below the F-F boundary. Almost all analytical samples show obvious tetrad effects. Remarkable M-shaped tetrad effects are observed in these samples with positive Eu anomaly. The characters of REE and some relative elements (Fe, Mn, Al, etc.) indicate that hydro- thermal activities occurred and resulted in seawater acidification in Upper and Lower Kellwasser horizons of the Late Devonian. The changes of marine environment caused by hydrothermal activities, such as seawater acidification, heavy metal pollution, and eutrophication, would destroy the neritic ecosystem and finally result in the F-F mass extinction.
基金supported by National Basic Research Program of China (Grant No. 2005CB422101)
文摘Lithologically, two kinds of chert can be recognized in the Middle-Upper Permian from the Tieqiao section in Laibin area, Guangxi, i.e., calcic chert occurring mainly in the Maokou Formation and pure chert mainly in the Wujiaping Formation. Geochemical data show that both kinds of chert contain very low A1203 (0-0.23%) and TiO2 (0.001%-0.024%) and low ZREE (0.55-19.94 ppm, averaging 9.97 ppm), as well as high ratio of Fe2O3/TiO2 (17-443, averaging 111) and low ratio of A1203/(Al2O3+Fe203) (0-0.26, averaging 0.09). Given that the average value Ce anomalies in chert deposited in the ridge-proximal environment is about 0.29, and that in the pelagic environment is about 0.60, the low Ce anomalies in the Tieqiao chert (0.24-0.46, averaging 0.35) imply that they were deposited in an ocean basin with influence of submarine hydrothermal fluid and no input of terrigenous materials. The vertical variation of the silica abundance in strata (SAIS) in the Middle-Upper Permian strata, together with the Eu anomalies and the ratios of ∑REE/Fe, indicates a relationship between the hydrothermal activity and the Emeishan basalt eruption, and that submarine hydrothermal activity was stronger in the Upper Permian (the Wujiapingian Stage) than in the Middle Permian (the Maokou Stage).