TiO2,CoS and SnO2 respectively by itself is inactive for the reduction of SO2 or/and NO by CO;however,we discovered that both TiO2- CoS (1:1 mass ratio) and TiO2- SnO2 (1:1 mass ratio) composite compounds are very...TiO2,CoS and SnO2 respectively by itself is inactive for the reduction of SO2 or/and NO by CO;however,we discovered that both TiO2- CoS (1:1 mass ratio) and TiO2- SnO2 (1:1 mass ratio) composite compounds are very active for such reactions,at 300- 350℃ ,the conversion of SO2 to S,NO to N2 are over 90% ,and the selectivity towards S or N2 are over 95% .These mean that there are synergism effects between TiO2 and CoS,TiO2 and SnO2.It was confirmed by XRD characterization that TiO2 and CoO,TiO2 and SnO2 transform to rutile after calcinations at 500℃ ,however,individual TiO2(anatase) can only transform to rutile up to 900℃ .Therefore ,it is suggested that the synergism effects must be related to these composites comcound which exist as rutile structure.The study of the reaction mechanism and model of active phase are underway.展开更多
Adsorption of water on sulfide surfaces and natural floatability of sulfide minerals were studied using density functional theory (DFT) method. All computational models were built in a vacuum environment to eliminat...Adsorption of water on sulfide surfaces and natural floatability of sulfide minerals were studied using density functional theory (DFT) method. All computational models were built in a vacuum environment to eliminate the effects of oxygen and other factors. H2O molecule prefers to stay with pyrite and sphalerite surfaces rather than water, whereas for galena, chalcocite, stibnite, and molybdenite, H2O molecule prefers to stay with water rather than the mineral surfaces. On the other hand, pyrite surface favors N2 more than water, while sphalerite surface cannot adsorb N2. These results show that galena, stibnite, chalcocite, and molybdenite are hydrophobic, while sphalerite is hydrophilic. Although pyrite has certain hydrophilicity, it tends to be aerophilic because the reaction of pyrite with H2O is weaker than pyrite with N2. Thus, pyrite, galena, chalcocite, stibnite and molybdenite all have natural floatability.展开更多
In order to fundamentally solve the acidification problem of high sulfur-containing bauxite during storage, by simulating the environment of minerals storage in laboratory, the acidification mechanism and influencing ...In order to fundamentally solve the acidification problem of high sulfur-containing bauxite during storage, by simulating the environment of minerals storage in laboratory, the acidification mechanism and influencing factors of high sulfur-containing bauxite were studied and confirmed using the single variable method to control the atmosphere, water and other variables. The results show that the acidification is mostly caused by the oxidation of sulfur-containing bauxite, which is mainly the natural oxidation of Pyrite(Fe S2), then the alkaline minerals dissolute in the presence of water, leading to the acidification phenomenon, which is influenced by moisture and air flow. Finally, more acid-producing substances are formed, resulting in the acidification of high sulfur-containing bauxite. The acidification of high sulfur-containing bauxite results from the combined effect of the oxygen in the air and water, which can be significantly alleviated by controlling the diffusion of the oxygen in air.展开更多
The desulfurization performance of the UDS solvents was investigated at an industrial side-stream plant and was compared with that of MDEA solvent.A mass transfer performance model was employed for explaining the COS ...The desulfurization performance of the UDS solvents was investigated at an industrial side-stream plant and was compared with that of MDEA solvent.A mass transfer performance model was employed for explaining the COS absorption into different solvents.Meanwhile,the regeneration performance of the UDS solvents was evaluated in side-stream tests.Results indicate that under the conditions covering an absorption temperature of 40℃,a pressure of 8.0 MPa,and a gas to liquid volume ratio(V/L)of around 230,the H2S content in purified gas can be reduced to 4.2 mg/m3 and 0 by using solvents UDS-II and UDS-III,respectively.Moreover,the total sulfur content in both purified gases is less than 80 mg/m3.As a result,the UDS-III solvent shows by 30 percentage points higher in COS removal efficiency than MDEA.In addition,the total volume mass transfer coefficient of UDS solvent is found to be twice higher than that of MDEA.Furthermore,the UDS solvents exhibit satisfactory thermal stability and regeneration performance.展开更多
The research aimed to analyze the linkage between natural vegetation, water dynamics and pyrite (FeS2) oxidation in tidal lowlands. The research was carried out in tidal lowland Pulau Rimau, South Sumatra from Febru...The research aimed to analyze the linkage between natural vegetation, water dynamics and pyrite (FeS2) oxidation in tidal lowlands. The research was carried out in tidal lowland Pulau Rimau, South Sumatra from February to December 2010. The field observations are done by exploring several transect on land units. The field description refers to Soil Survey Staff. Water and soil samples were taken from selected key areas for laboratory analyses. The vegetation data were collected by making sample plots placed on each vegetation type with plot sizes 10 m × 10 m for secondary forests and 5 m × 5 m for shrubs and grass. The observations of surface water level were done during the river receding with units of meter above sea level (m.asl). The results shows that pyrite formation is largely determined by the availability of natural vegetation as S (sulfur) donors, climate and uncontrolled water balance and supporting faunas such as crabs and mud shrimp. Climate and water balance as well as supporting faunas is the main supporting factors to accelerate the process of formation pyrite. Oxidized pyrite increases soil pH thus toxic to fish, arable soils, plant growth, disturbing the water quality and soil nutrient availability. Oxidized pyrite is predominantly accelerated by the dynamics of river water and disturbed natural vegetation by human activities, and the pyrite oxidation management approach is divided into three main components of technologies, namely water management, land management and commodity management.展开更多
Soil salinization may negatively affect microbial processes related to carbon dioxide (CO2) and nitrous oxide (N20) emissions. A short-term laboratory incubation experiment was conducted to investigate the effects...Soil salinization may negatively affect microbial processes related to carbon dioxide (CO2) and nitrous oxide (N20) emissions. A short-term laboratory incubation experiment was conducted to investigate the effects of soil electrical conductivity (EC) and moisture content on CO2 and N20 emissions from sulfate-based natural saline soils. Three separate 100-m long transects were established along the salinity gradient on a salt-affected agricultural field at Mooreton, North Dakota, USA. Surface soils were collected from four equally spaced sampling positions within each transect, at the depths of 0-15 and 15-30 cm. In the laboratory, artificial soil cores were formed combining soils from both the depths in each transect, and incubated at 60% and 90% water-filled pore space (WFPS) at 25 ~C. The measured depth-weighted EC of the saturated paste extract (ECe) across the sampling positions ranged from 0.43 to 4.65 dS m-1. Potential nitrogen (N) mineralization rate and CO2 emissions decreased with increasing soil ECe, but the relative decline in soil CO2 emissions with increasing ECe was smaller at 60% WFPS than at 90% WFPS. At 60% WFPS, soil N20 emissions decreased from 133 g N20-N kg-1 soil at ECe ( 0.50 dS m-1 to 72 μg N20-N kg-1 soil at ECe = 4.65 dS m-1. In contrast, at 90% WFPS, soil N20 emissions increased from 262 g N20-N kg-1 soil at ECe : 0.81 dS m-1 to 849 g N20-N kg-1 soil at ECe : 4.65 dS m-1, suggesting that N20 emissions were linked to both soil ECe and moisture content. Therefore, spatial variability in soil ECe and pattern of rainfall over the season need to be considered when up-scaling N20 and CO2 emissions from field to landscape scales.展开更多
文摘TiO2,CoS and SnO2 respectively by itself is inactive for the reduction of SO2 or/and NO by CO;however,we discovered that both TiO2- CoS (1:1 mass ratio) and TiO2- SnO2 (1:1 mass ratio) composite compounds are very active for such reactions,at 300- 350℃ ,the conversion of SO2 to S,NO to N2 are over 90% ,and the selectivity towards S or N2 are over 95% .These mean that there are synergism effects between TiO2 and CoS,TiO2 and SnO2.It was confirmed by XRD characterization that TiO2 and CoO,TiO2 and SnO2 transform to rutile after calcinations at 500℃ ,however,individual TiO2(anatase) can only transform to rutile up to 900℃ .Therefore ,it is suggested that the synergism effects must be related to these composites comcound which exist as rutile structure.The study of the reaction mechanism and model of active phase are underway.
基金Project(51164001)supported by the National Natural Science Foundation of ChinaProject(NCET-11-0925)supported by New Century Excellent Talents in University,China
文摘Adsorption of water on sulfide surfaces and natural floatability of sulfide minerals were studied using density functional theory (DFT) method. All computational models were built in a vacuum environment to eliminate the effects of oxygen and other factors. H2O molecule prefers to stay with pyrite and sphalerite surfaces rather than water, whereas for galena, chalcocite, stibnite, and molybdenite, H2O molecule prefers to stay with water rather than the mineral surfaces. On the other hand, pyrite surface favors N2 more than water, while sphalerite surface cannot adsorb N2. These results show that galena, stibnite, chalcocite, and molybdenite are hydrophobic, while sphalerite is hydrophilic. Although pyrite has certain hydrophilicity, it tends to be aerophilic because the reaction of pyrite with H2O is weaker than pyrite with N2. Thus, pyrite, galena, chalcocite, stibnite and molybdenite all have natural floatability.
基金Project(2013AA064102)supported by the National High Technology Research and Development Program of China
文摘In order to fundamentally solve the acidification problem of high sulfur-containing bauxite during storage, by simulating the environment of minerals storage in laboratory, the acidification mechanism and influencing factors of high sulfur-containing bauxite were studied and confirmed using the single variable method to control the atmosphere, water and other variables. The results show that the acidification is mostly caused by the oxidation of sulfur-containing bauxite, which is mainly the natural oxidation of Pyrite(Fe S2), then the alkaline minerals dissolute in the presence of water, leading to the acidification phenomenon, which is influenced by moisture and air flow. Finally, more acid-producing substances are formed, resulting in the acidification of high sulfur-containing bauxite. The acidification of high sulfur-containing bauxite results from the combined effect of the oxygen in the air and water, which can be significantly alleviated by controlling the diffusion of the oxygen in air.
基金financial support from the National Key Science and Technology Project of China (2011ZX05017-005)the Fundamental Research Funds for the Central Universities (No.22A201514010)
文摘The desulfurization performance of the UDS solvents was investigated at an industrial side-stream plant and was compared with that of MDEA solvent.A mass transfer performance model was employed for explaining the COS absorption into different solvents.Meanwhile,the regeneration performance of the UDS solvents was evaluated in side-stream tests.Results indicate that under the conditions covering an absorption temperature of 40℃,a pressure of 8.0 MPa,and a gas to liquid volume ratio(V/L)of around 230,the H2S content in purified gas can be reduced to 4.2 mg/m3 and 0 by using solvents UDS-II and UDS-III,respectively.Moreover,the total sulfur content in both purified gases is less than 80 mg/m3.As a result,the UDS-III solvent shows by 30 percentage points higher in COS removal efficiency than MDEA.In addition,the total volume mass transfer coefficient of UDS solvent is found to be twice higher than that of MDEA.Furthermore,the UDS solvents exhibit satisfactory thermal stability and regeneration performance.
文摘The research aimed to analyze the linkage between natural vegetation, water dynamics and pyrite (FeS2) oxidation in tidal lowlands. The research was carried out in tidal lowland Pulau Rimau, South Sumatra from February to December 2010. The field observations are done by exploring several transect on land units. The field description refers to Soil Survey Staff. Water and soil samples were taken from selected key areas for laboratory analyses. The vegetation data were collected by making sample plots placed on each vegetation type with plot sizes 10 m × 10 m for secondary forests and 5 m × 5 m for shrubs and grass. The observations of surface water level were done during the river receding with units of meter above sea level (m.asl). The results shows that pyrite formation is largely determined by the availability of natural vegetation as S (sulfur) donors, climate and uncontrolled water balance and supporting faunas such as crabs and mud shrimp. Climate and water balance as well as supporting faunas is the main supporting factors to accelerate the process of formation pyrite. Oxidized pyrite increases soil pH thus toxic to fish, arable soils, plant growth, disturbing the water quality and soil nutrient availability. Oxidized pyrite is predominantly accelerated by the dynamics of river water and disturbed natural vegetation by human activities, and the pyrite oxidation management approach is divided into three main components of technologies, namely water management, land management and commodity management.
文摘Soil salinization may negatively affect microbial processes related to carbon dioxide (CO2) and nitrous oxide (N20) emissions. A short-term laboratory incubation experiment was conducted to investigate the effects of soil electrical conductivity (EC) and moisture content on CO2 and N20 emissions from sulfate-based natural saline soils. Three separate 100-m long transects were established along the salinity gradient on a salt-affected agricultural field at Mooreton, North Dakota, USA. Surface soils were collected from four equally spaced sampling positions within each transect, at the depths of 0-15 and 15-30 cm. In the laboratory, artificial soil cores were formed combining soils from both the depths in each transect, and incubated at 60% and 90% water-filled pore space (WFPS) at 25 ~C. The measured depth-weighted EC of the saturated paste extract (ECe) across the sampling positions ranged from 0.43 to 4.65 dS m-1. Potential nitrogen (N) mineralization rate and CO2 emissions decreased with increasing soil ECe, but the relative decline in soil CO2 emissions with increasing ECe was smaller at 60% WFPS than at 90% WFPS. At 60% WFPS, soil N20 emissions decreased from 133 g N20-N kg-1 soil at ECe ( 0.50 dS m-1 to 72 μg N20-N kg-1 soil at ECe = 4.65 dS m-1. In contrast, at 90% WFPS, soil N20 emissions increased from 262 g N20-N kg-1 soil at ECe : 0.81 dS m-1 to 849 g N20-N kg-1 soil at ECe : 4.65 dS m-1, suggesting that N20 emissions were linked to both soil ECe and moisture content. Therefore, spatial variability in soil ECe and pattern of rainfall over the season need to be considered when up-scaling N20 and CO2 emissions from field to landscape scales.