Acid Mine Drainage(AMD)from coal mining is a serious environmental issue which affects water quality,ecology,and the overall landscape of the basin.A large number of coal mine tailings in the mountainous regions of Gu...Acid Mine Drainage(AMD)from coal mining is a serious environmental issue which affects water quality,ecology,and the overall landscape of the basin.A large number of coal mine tailings in the mountainous regions of Guizhou Province,China were unattended and iron-rich AMD was directly discharged to the rivers.This discharge leaves the river―yellow‖and heavily polluted.This study tries to find an efficient and economical method for treating iron-rich AMD.We sampled AMD water in two sites:Yangliujie town of Duyun city(hereafter,called Yangliujie),and Xinglong Coal Mine,Duliu town of Guiding county(hereafter,called Xinglong).We performed iron removal laboratory experiment with Cement-Bentonite Agent(CBA,80%cement and 20%bentonite)in 500 mL AMD water from Yangliujie,scale-up experiment in 15 L AMD water from both Yangliujie and Xinglong,and engineering application in Xinglong respectively.Laboratory experiment results showed the iron removal rate can reach 99.8%and the removal rate depends on the CBA dosage and the treatment time.In the scale-up experiment,we found that Fe concentration could be reduced from 587.0 to 0.2 mg/L when adding 20 g/L CBA to the AMD water and aerating for 3 hours.As sampled water in Xinglong has a very high Fe concentration(Fe 1019.8 mg/L)and the concentration varies with seasons,it is not economical to add the CBA directly to the AMD water.Considering the abundant and cheap limestone resources in Guizhou,we used a twostep treatment method,first we added CaCO3 to raise the pH,and then we took the supernatant liquor and added CBA to the liquor.It was shown that 15 g/L of CBA was a good dosage for iron removal with Fe concentration being reduced from 1019.8 to 0.3 mg/L when CaCO3 was used to raise the pH.The best treatment realized over 99.9%iron removal,99.2%NH3-N removal,98.9%CODMn removal,and heavy metals in the treated water were reduced to under the limit stipulated in the―Environmental Quality Standards of Surface Water in China‖.Thus in the engineering application,we used this two-step treatment method.After the treatment,the pH of the iron-rich AMD(pH 2.86,Fe 2624.6 mg/L)increased to 8.53,the concentration of Fe was reduced to 59.5 mg/L,NH3-N decreased from 16.15 to less than 0.05 mg/L,CODMn decreased from 323.33 to 24.57 mg/L,heavy metals except Fe and Mn were reduced to under the limit of surface water.In conclusion,the use of CBA can effectively remove Fe and other heavy metals from the iron-rich AMD and adjust the pH value to the range of a natural water body.展开更多
A series of iron-based Fischer-Tropsch synthesis （FTS） catalysts incorporated with Al2O3 binder were prepared by the combination of co-precipitation and spray drying technology. The catalyst samples were characteriz...A series of iron-based Fischer-Tropsch synthesis （FTS） catalysts incorporated with Al2O3 binder were prepared by the combination of co-precipitation and spray drying technology. The catalyst samples were characterized by using N2 physical adsorption, temperature-programmed reduction/desorption （TPR/TPD） and MSssbauer effect spectroscopy （MES） methods. The characterization results indicated that the BET surface area increases with increasing Al2O3 content and passes through a maximum at the Al2O3/Fe ratio of 10/100 （weight basis）. After the point, it decreases with further increase in Al2O3 content. The incorporation of Al2O3 binder was found to weaken the surface basicity and suppress the reduction and carburization of iron-based catalysts probably due to the strong K-Al2O3 and Fe-Al2O3 interactions. Furthermore, the H2 adsorption ability of the catalysts is enhanced with increasing Al2O3 content. The FTS performances of the catalysts were tested in a slurry-phase continuously stirred tank reactor （CSTR） under the reaction conditions of 260 ℃, 1.5 MPa, 1000 h^-1 and molar ratio of H2/CO 0.67 for 200 h. The results showed that the addition of small amounts of Al2O3 affects the activity of iron-based catalysts to a little extent. However, with further increase of Al2O3 content, the FTS activity and water gas shift reaction （WGS） activity are decreased severely. The addition of appropriate Al2O3 do not affect the product selectivity, but the catalysts incorporated with large amounts of Al2O3 have higher selectivity for light hydrocarbons and lower selectivity for heavy hydrocarbons.展开更多
The effect of heat treatment mode on the microstructure of Fe-Cr-B cast iron alloys was investigated inthis paper by comparing the difference of precipitation patterns of secondary particles after thermal cycling trea...The effect of heat treatment mode on the microstructure of Fe-Cr-B cast iron alloys was investigated inthis paper by comparing the difference of precipitation patterns of secondary particles after thermal cycling treatment(TCT) with those after normal heat treatment (NHT). No obvious differences were found in precipitation patterns ofsecondary particles between TCT and NHT when experimental temperature was below Ar1. However, whentemperature was over Ar1, there were significant differences, with secondary particles prominently segregated at thegrain boundaries under TCT, while the particles evenly distributed in the matrix under NHT. The reason for themicrostructure differences could be associated with the development of non-equilibrium segregation of boron duringTCT.展开更多
Water-logging and the inability to take up sufficient iron (Fe), causing iron deficiency chlorosis (IDC) in soybean (<em>Glycine max</em>, L. Merr.), can be major yield reducing factors in certain soils in...Water-logging and the inability to take up sufficient iron (Fe), causing iron deficiency chlorosis (IDC) in soybean (<em>Glycine max</em>, L. Merr.), can be major yield reducing factors in certain soils in the northern USA and Manitoba, Canada, soybean growing regions. The objective of this research was to evaluate soybean IDC, biomass production, and yield with seeding on raised beds and seed application of the Fe-chelate compound ortho-ortho-Fe-EDDHA. In six environments, soybean were seeded on raised beds and conventionally prepared seedbeds (flat) and with a factorial arrangement of five cultivars (within adapted maturity group 0.1 to 0.9 and variable IDC tolerance) and seed applied Fe-EDDHA using rates of 0 kg<span style="white-space:nowrap;"><span style="white-space:nowrap;">·</span></span>ha<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup> and 3.36 kg<span style="white-space:nowrap;"><span style="white-space:nowrap;">·</span></span>ha<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup>. There were no significant interactions between the factors tested. The plant population was 27% higher on the raised beds compared with flat, and yield was 6.3% higher (2893 kg<span style="white-space:nowrap;"><span style="white-space:nowrap;">·</span></span>ha<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup> vs. 2722 kg<span style="white-space:nowrap;"><span style="white-space:nowrap;">·</span></span>ha<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup>). Total dry plant biomass on raised beds was 9.8% greater compared with flat. The plant population with seed applied Fe-EDDHA was 10.6% lower compared with no application. However, the IDC score was significantly lower 2.2 vs 2.4 (1 = green, 5 = dead) for Fe-EDDHA seed application. Yield and plant biomass were not significantly different between Fe treatments. Raised beds offer an opportunity for soybean growers to reduce the negative influence of excessive water. Further research is needed to determine the long-term effect of raised beds on plant development, IDC expression, and yield. The application of Fe-EDDHA remains a partial solution and should therefore be combined with other methods to reduce IDC. Further research should study other Fe-EDDHA application rates and methods.展开更多
Insoluble constituents in 3104 alloy for beverage cans manufacturing play an important role in deep ironing process. This paper studies the effect of Fe content in the alloy on volume fraction of the constituents Al6(...Insoluble constituents in 3104 alloy for beverage cans manufacturing play an important role in deep ironing process. This paper studies the effect of Fe content in the alloy on volume fraction of the constituents Al6(Fe, Mn)3 and Al12(Fe, Mn)3Si and its influence on ironing die pickup. It is shown that with Fe content increase, the amount of these constituents rises that helps prevent tool galling. Trials made at a can plant showed less ironing die changeovers at bodymakers. The optimum Fe content for aluminum can production can be considered between 0.47% and 0.53% that corresponds to 2.0% - 2.3% of insoluble constituent volume fraction. Greater amounts than this cause problems with excessive constituent particle formation and earing;smaller amounts result in increased ironing die galling.展开更多
Fe-based amorphous alloys with ductility were synthesized using the commercial cast iron QT50 (denoted as QT) with the combining minor addition of B and Al by single roller melt-spinning. The melt-spun (QT1-xBx)99Al1 ...Fe-based amorphous alloys with ductility were synthesized using the commercial cast iron QT50 (denoted as QT) with the combining minor addition of B and Al by single roller melt-spinning. The melt-spun (QT1-xBx)99Al1 (x is from 0.006wt% to 0.01wt%) amorphous alloys exhibit onset crystallization temperatures and Curie temperatures of 759-780 and 629-642 K respectively, and whi- ch increase with B content. The amorphous ribbons are ductile and can be bent 180° without breaking. With the increase in B content from 0.006wt% to 0.01wt%, the Vickers microhardness of the amorphous alloys increases from Hv 830 to Hv 1110. The effects of the additional B and Al elements on the glass forming ability and mechanical properties were also discussed.展开更多
基金supported by"Guizhou Coal Mine Water Control Technology Research and Development"projectthe Department of Science and Technology of Sichuan Province(20GJHZ0296)。
文摘Acid Mine Drainage(AMD)from coal mining is a serious environmental issue which affects water quality,ecology,and the overall landscape of the basin.A large number of coal mine tailings in the mountainous regions of Guizhou Province,China were unattended and iron-rich AMD was directly discharged to the rivers.This discharge leaves the river―yellow‖and heavily polluted.This study tries to find an efficient and economical method for treating iron-rich AMD.We sampled AMD water in two sites:Yangliujie town of Duyun city(hereafter,called Yangliujie),and Xinglong Coal Mine,Duliu town of Guiding county(hereafter,called Xinglong).We performed iron removal laboratory experiment with Cement-Bentonite Agent(CBA,80%cement and 20%bentonite)in 500 mL AMD water from Yangliujie,scale-up experiment in 15 L AMD water from both Yangliujie and Xinglong,and engineering application in Xinglong respectively.Laboratory experiment results showed the iron removal rate can reach 99.8%and the removal rate depends on the CBA dosage and the treatment time.In the scale-up experiment,we found that Fe concentration could be reduced from 587.0 to 0.2 mg/L when adding 20 g/L CBA to the AMD water and aerating for 3 hours.As sampled water in Xinglong has a very high Fe concentration(Fe 1019.8 mg/L)and the concentration varies with seasons,it is not economical to add the CBA directly to the AMD water.Considering the abundant and cheap limestone resources in Guizhou,we used a twostep treatment method,first we added CaCO3 to raise the pH,and then we took the supernatant liquor and added CBA to the liquor.It was shown that 15 g/L of CBA was a good dosage for iron removal with Fe concentration being reduced from 1019.8 to 0.3 mg/L when CaCO3 was used to raise the pH.The best treatment realized over 99.9%iron removal,99.2%NH3-N removal,98.9%CODMn removal,and heavy metals in the treated water were reduced to under the limit stipulated in the―Environmental Quality Standards of Surface Water in China‖.Thus in the engineering application,we used this two-step treatment method.After the treatment,the pH of the iron-rich AMD(pH 2.86,Fe 2624.6 mg/L)increased to 8.53,the concentration of Fe was reduced to 59.5 mg/L,NH3-N decreased from 16.15 to less than 0.05 mg/L,CODMn decreased from 323.33 to 24.57 mg/L,heavy metals except Fe and Mn were reduced to under the limit of surface water.In conclusion,the use of CBA can effectively remove Fe and other heavy metals from the iron-rich AMD and adjust the pH value to the range of a natural water body.
基金The financial support from the National Natural Science Foundation of China (20590361)the National Outstanding Young Scientists Foundation of China (20625620)
文摘A series of iron-based Fischer-Tropsch synthesis （FTS） catalysts incorporated with Al2O3 binder were prepared by the combination of co-precipitation and spray drying technology. The catalyst samples were characterized by using N2 physical adsorption, temperature-programmed reduction/desorption （TPR/TPD） and MSssbauer effect spectroscopy （MES） methods. The characterization results indicated that the BET surface area increases with increasing Al2O3 content and passes through a maximum at the Al2O3/Fe ratio of 10/100 （weight basis）. After the point, it decreases with further increase in Al2O3 content. The incorporation of Al2O3 binder was found to weaken the surface basicity and suppress the reduction and carburization of iron-based catalysts probably due to the strong K-Al2O3 and Fe-Al2O3 interactions. Furthermore, the H2 adsorption ability of the catalysts is enhanced with increasing Al2O3 content. The FTS performances of the catalysts were tested in a slurry-phase continuously stirred tank reactor （CSTR） under the reaction conditions of 260 ℃, 1.5 MPa, 1000 h^-1 and molar ratio of H2/CO 0.67 for 200 h. The results showed that the addition of small amounts of Al2O3 affects the activity of iron-based catalysts to a little extent. However, with further increase of Al2O3 content, the FTS activity and water gas shift reaction （WGS） activity are decreased severely. The addition of appropriate Al2O3 do not affect the product selectivity, but the catalysts incorporated with large amounts of Al2O3 have higher selectivity for light hydrocarbons and lower selectivity for heavy hydrocarbons.
文摘The effect of heat treatment mode on the microstructure of Fe-Cr-B cast iron alloys was investigated inthis paper by comparing the difference of precipitation patterns of secondary particles after thermal cycling treatment(TCT) with those after normal heat treatment (NHT). No obvious differences were found in precipitation patterns ofsecondary particles between TCT and NHT when experimental temperature was below Ar1. However, whentemperature was over Ar1, there were significant differences, with secondary particles prominently segregated at thegrain boundaries under TCT, while the particles evenly distributed in the matrix under NHT. The reason for themicrostructure differences could be associated with the development of non-equilibrium segregation of boron duringTCT.
文摘Water-logging and the inability to take up sufficient iron (Fe), causing iron deficiency chlorosis (IDC) in soybean (<em>Glycine max</em>, L. Merr.), can be major yield reducing factors in certain soils in the northern USA and Manitoba, Canada, soybean growing regions. The objective of this research was to evaluate soybean IDC, biomass production, and yield with seeding on raised beds and seed application of the Fe-chelate compound ortho-ortho-Fe-EDDHA. In six environments, soybean were seeded on raised beds and conventionally prepared seedbeds (flat) and with a factorial arrangement of five cultivars (within adapted maturity group 0.1 to 0.9 and variable IDC tolerance) and seed applied Fe-EDDHA using rates of 0 kg<span style="white-space:nowrap;"><span style="white-space:nowrap;">·</span></span>ha<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup> and 3.36 kg<span style="white-space:nowrap;"><span style="white-space:nowrap;">·</span></span>ha<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup>. There were no significant interactions between the factors tested. The plant population was 27% higher on the raised beds compared with flat, and yield was 6.3% higher (2893 kg<span style="white-space:nowrap;"><span style="white-space:nowrap;">·</span></span>ha<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup> vs. 2722 kg<span style="white-space:nowrap;"><span style="white-space:nowrap;">·</span></span>ha<sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>1</sup>). Total dry plant biomass on raised beds was 9.8% greater compared with flat. The plant population with seed applied Fe-EDDHA was 10.6% lower compared with no application. However, the IDC score was significantly lower 2.2 vs 2.4 (1 = green, 5 = dead) for Fe-EDDHA seed application. Yield and plant biomass were not significantly different between Fe treatments. Raised beds offer an opportunity for soybean growers to reduce the negative influence of excessive water. Further research is needed to determine the long-term effect of raised beds on plant development, IDC expression, and yield. The application of Fe-EDDHA remains a partial solution and should therefore be combined with other methods to reduce IDC. Further research should study other Fe-EDDHA application rates and methods.
文摘Insoluble constituents in 3104 alloy for beverage cans manufacturing play an important role in deep ironing process. This paper studies the effect of Fe content in the alloy on volume fraction of the constituents Al6(Fe, Mn)3 and Al12(Fe, Mn)3Si and its influence on ironing die pickup. It is shown that with Fe content increase, the amount of these constituents rises that helps prevent tool galling. Trials made at a can plant showed less ironing die changeovers at bodymakers. The optimum Fe content for aluminum can production can be considered between 0.47% and 0.53% that corresponds to 2.0% - 2.3% of insoluble constituent volume fraction. Greater amounts than this cause problems with excessive constituent particle formation and earing;smaller amounts result in increased ironing die galling.
基金This work was financially supported by the National Natural Science Foundation of China (No.50225103, 50471001 and 50631010).
文摘Fe-based amorphous alloys with ductility were synthesized using the commercial cast iron QT50 (denoted as QT) with the combining minor addition of B and Al by single roller melt-spinning. The melt-spun (QT1-xBx)99Al1 (x is from 0.006wt% to 0.01wt%) amorphous alloys exhibit onset crystallization temperatures and Curie temperatures of 759-780 and 629-642 K respectively, and whi- ch increase with B content. The amorphous ribbons are ductile and can be bent 180° without breaking. With the increase in B content from 0.006wt% to 0.01wt%, the Vickers microhardness of the amorphous alloys increases from Hv 830 to Hv 1110. The effects of the additional B and Al elements on the glass forming ability and mechanical properties were also discussed.
