Carboxymethyl starchs（CMS） with low and high degrees of substitution（CMSL and CMSH in short,respectively） were employed as depressants of diaspore in cationic reverse flotation using dodecylamine（DDA） as collect...Carboxymethyl starchs（CMS） with low and high degrees of substitution（CMSL and CMSH in short,respectively） were employed as depressants of diaspore in cationic reverse flotation using dodecylamine（DDA） as collector.The effect of degree of substitution of CMS on its depression performance was examined and the interaction mode and behavior were investigated in a comparative manner.Micro-flotation test showed that CMSL exhibited better performance in depressing diaspore than CMSH in a broad pH range.The adsorption of CMS on diaspore was studied by adsorption test,zeta potential measurement,and atomic force microscopy.It was found that CMSH corresponds to lower adsorption amount,thinner adsorption layer,and more negative charge than CMSL,resulting from the more chelating sites brought by the high degree of substitution.The surface tension measurement and DDA adsorption test further revealed that CMSL/DDA system gives a better depressing performance benefiting from the trapping effect by enveloping some DDA molecules inside the loop chains,while CMSH/DDA system is likely considered a quasi-surfactant.展开更多
In this paper,an ab initio,local density functional(LDF)method was used to explore the relationship between the molecular properties of additives and the lubricating performance of aluminum rolling oil.The structural ...In this paper,an ab initio,local density functional(LDF)method was used to explore the relationship between the molecular properties of additives and the lubricating performance of aluminum rolling oil.The structural properties of butyl stearate,dodecanol,docosanol,and methyl dodecanoate were studied according to the density functional theory.The calculated data showed that the atoms in or around the functional groups might be likely the reacting sites.Because of the different functional groups and structure of ester and alcohol,two types of complex additives,dodecanol and butyl stearate,methyl dodecanoate and butyl stearate,respectively,were chosen for studying their tribological properties and performing aluminum cold rolling experiments.The test results agreed with the calculated results very well.The complex ester,viz.methyl dodecanoate and butyl stearate,had the best lubricating performance with a friction coefficient of 0.084 1 and a permissive-rolling thickness of 0.040 mm as compared with that of dodecanol-butyl stearate-base oil formulation.展开更多
The floatability of diaspore and three kinds of silicate minerals,including kaolinite,illite and pyrophyllite,by a cationic Gemini surfactant as collector and starch as depressant was investigated as function of reage...The floatability of diaspore and three kinds of silicate minerals,including kaolinite,illite and pyrophyllite,by a cationic Gemini surfactant as collector and starch as depressant was investigated as function of reagents concentration and pulp pH.Further studies of artificially mixed minerals and bauxite ore were also detailedly conducted.At last,the pre-desliming reverse flotation separation process was adopted.It can be concluded that the combinational use of a Gemini cationic collector and the starch depressant is effective.The concentrates with Al2O3 to SiO2 mass ratio of 9.66 and the recovery of Al2O3 of 71.73% are obtained from natural bauxite ore(A/S=5.70) at pH value of around 10.展开更多
Abstract： The present article compares the propane dehydrogenation performance of alumina binder-added PtSnNa/ A1SBA-15 catalysts prepared via three different procedures in comparison with the performance of a binder...Abstract： The present article compares the propane dehydrogenation performance of alumina binder-added PtSnNa/ A1SBA-15 catalysts prepared via three different procedures in comparison with the performance of a binder-free PtSnNa/ AISBA-15 catalyst. All these catalysts have been investigated by reaction tests and some physico-chemical characterizations such as BET, H2 chemisorption, catalytic grain crushing strength, NHa-TPD and TPO analyses. Test results showed that the addition of alumina binder could enhance the mechanical strength of catalyst evidently. Moreover, the different preparation procedures not only modified the characteristics of both acid and metal functions but also affected the coke deposition on the catalysts. Among these catalysts studied, the catalyst prepared by impregnation followed by the agglomeration of alumi- na binder had exhibited the highest catalytic activity and stability compared with other catalyst samples undergoing different preparation procedures. The possible reason may be attributed to the highest metallic dispersion and the strong interactions among Pt, Sn and the support.展开更多
The chemical composition, structure and thermal stability of the spent FCC equilibrium catalyst from an oil refinery were characterized by XRD, FT-IR, DTA-TG, BET, complete chemical analysis, SEM, and XRF. The spent F...The chemical composition, structure and thermal stability of the spent FCC equilibrium catalyst from an oil refinery were characterized by XRD, FT-IR, DTA-TG, BET, complete chemical analysis, SEM, and XRF. The spent FCC equilibrium catalyst, clay, barium carbonate, and talc were used as the main raw materials to prepare the alumina abrasion-resistant ceramic balls to be used in the powder grinding mill for manufacture of architecture tiles. The results showed that after proper formulation study, the spent FCC equilibrium catalyst could replace industrial alumina to prepare high performance grinding balls. Meanwhile, the various performance indices of the grinding ball could meet the quality standard for similar products, and additionally, the energy saving effect was achieved in the operation of the grinding section, resulting in a successful comprehensive utilization of solid wastes.展开更多
基金Projects (50804055,50974134) supported by the National Natural Science Foundation of ChinaProject (09JJ3100) supported by the Natural Science Foundation of Hunan Province,China
文摘Carboxymethyl starchs（CMS） with low and high degrees of substitution（CMSL and CMSH in short,respectively） were employed as depressants of diaspore in cationic reverse flotation using dodecylamine（DDA） as collector.The effect of degree of substitution of CMS on its depression performance was examined and the interaction mode and behavior were investigated in a comparative manner.Micro-flotation test showed that CMSL exhibited better performance in depressing diaspore than CMSH in a broad pH range.The adsorption of CMS on diaspore was studied by adsorption test,zeta potential measurement,and atomic force microscopy.It was found that CMSH corresponds to lower adsorption amount,thinner adsorption layer,and more negative charge than CMSL,resulting from the more chelating sites brought by the high degree of substitution.The surface tension measurement and DDA adsorption test further revealed that CMSL/DDA system gives a better depressing performance benefiting from the trapping effect by enveloping some DDA molecules inside the loop chains,while CMSH/DDA system is likely considered a quasi-surfactant.
基金the financial support of this study provided by the National Natural Science Foundation of China(No.51274037)the Cooperation Program between USTB and SINOPEC(No.112116)
文摘In this paper,an ab initio,local density functional(LDF)method was used to explore the relationship between the molecular properties of additives and the lubricating performance of aluminum rolling oil.The structural properties of butyl stearate,dodecanol,docosanol,and methyl dodecanoate were studied according to the density functional theory.The calculated data showed that the atoms in or around the functional groups might be likely the reacting sites.Because of the different functional groups and structure of ester and alcohol,two types of complex additives,dodecanol and butyl stearate,methyl dodecanoate and butyl stearate,respectively,were chosen for studying their tribological properties and performing aluminum cold rolling experiments.The test results agreed with the calculated results very well.The complex ester,viz.methyl dodecanoate and butyl stearate,had the best lubricating performance with a friction coefficient of 0.084 1 and a permissive-rolling thickness of 0.040 mm as compared with that of dodecanol-butyl stearate-base oil formulation.
基金Project(50874118) supported by the National Natural Science Foundation of ChinaProject(2007B52) supported by the Foundation for the Author of National Excellent Doctoral Dissertation of ChinaProject(2005CB623701) supported by the National Basic Research Program of China
文摘The floatability of diaspore and three kinds of silicate minerals,including kaolinite,illite and pyrophyllite,by a cationic Gemini surfactant as collector and starch as depressant was investigated as function of reagents concentration and pulp pH.Further studies of artificially mixed minerals and bauxite ore were also detailedly conducted.At last,the pre-desliming reverse flotation separation process was adopted.It can be concluded that the combinational use of a Gemini cationic collector and the starch depressant is effective.The concentrates with Al2O3 to SiO2 mass ratio of 9.66 and the recovery of Al2O3 of 71.73% are obtained from natural bauxite ore(A/S=5.70) at pH value of around 10.
基金the National Nature Science Foundation of China(50873026,and21106017)the Production and Research Prospective Joint Research Project(BY2009153)+1 种基金the Science and Technology Support Program(BE2008129) of Jiangsu Province of ChinaSpecialized Research Fund for the Doctoral Program of Higher Education of China(20100092120047) for financial supports
文摘Abstract： The present article compares the propane dehydrogenation performance of alumina binder-added PtSnNa/ A1SBA-15 catalysts prepared via three different procedures in comparison with the performance of a binder-free PtSnNa/ AISBA-15 catalyst. All these catalysts have been investigated by reaction tests and some physico-chemical characterizations such as BET, H2 chemisorption, catalytic grain crushing strength, NHa-TPD and TPO analyses. Test results showed that the addition of alumina binder could enhance the mechanical strength of catalyst evidently. Moreover, the different preparation procedures not only modified the characteristics of both acid and metal functions but also affected the coke deposition on the catalysts. Among these catalysts studied, the catalyst prepared by impregnation followed by the agglomeration of alumi- na binder had exhibited the highest catalytic activity and stability compared with other catalyst samples undergoing different preparation procedures. The possible reason may be attributed to the highest metallic dispersion and the strong interactions among Pt, Sn and the support.
基金the funding provided by the Fujian Provincial Education Department Project(JA09054)the Project administered by the Fujian Normal University(XG-004)+4 种基金the Fujian Provincial Eco- nomic and Trade Commission Project(HE0536)the Open Project of the MOE's Key Laboratory for Medical and Photoelectrical Science and Technology(JYG0821)the Open Project of Hubei Province,the State Nationalities Committee,and the MOE Joint Key Laboratory for Catalytic Material Science(CHCL08008)the Fujian Provincial Testing Fund Project for the Key Laboratory of Highmolecular Materials(FJKL-POLY2010-17)the Training for Excellence Youth Skeleton Teacher of Fujian Normal University(No.2008100228).
文摘The chemical composition, structure and thermal stability of the spent FCC equilibrium catalyst from an oil refinery were characterized by XRD, FT-IR, DTA-TG, BET, complete chemical analysis, SEM, and XRF. The spent FCC equilibrium catalyst, clay, barium carbonate, and talc were used as the main raw materials to prepare the alumina abrasion-resistant ceramic balls to be used in the powder grinding mill for manufacture of architecture tiles. The results showed that after proper formulation study, the spent FCC equilibrium catalyst could replace industrial alumina to prepare high performance grinding balls. Meanwhile, the various performance indices of the grinding ball could meet the quality standard for similar products, and additionally, the energy saving effect was achieved in the operation of the grinding section, resulting in a successful comprehensive utilization of solid wastes.
