Bentonite is a necessary binder in producing pellets.Its excessive use reduces the iron grade of pellets and increases production costs.Minimizing bentonite dosage is essential for producing high-quality iron ore pell...Bentonite is a necessary binder in producing pellets.Its excessive use reduces the iron grade of pellets and increases production costs.Minimizing bentonite dosage is essential for producing high-quality iron ore pellets.Addressing the gap in the application of organically-intercalated modified bentonite in the pelletizing field,this study introduces an innovative modification process for bentonite that employs the synergistic effect of mechanical force and dimethyl sulfoxide to enhance the intercalation of organic compounds within bentonite,thus significantly enhancing its binding performance.The colloid value and swell capacity of modified bentonite(98.5 m L/3g and 55.0 m L/g)were much higher than the original bentonite(90.5 m L/3g and 17.5 m L/g).With the decrease of bentonite dosage from1.5wt%to 1.0wt%,the drop number of green pellets from a height of 0.5 m and the compressive strengths of roasted pellets using the modified bentonite(6.0 times and 2916 N per pellet)were significantly higher than those of the original bentonite(4.0 times and 2739 N per pellet).This study provides a comprehensive analysis of the intercalation modification mechanism of bentonite,offering crucial technical insights for the development of high-performance modified bentonite as iron ore pellet binders.展开更多
DBUH-Br_3 catalyzed selective conversion of sulfides to sulfoxides in the presence of H_2O_2 as oxidizing agent is described.The reaction was performed selectively at room temperature and relatively short reaction times.
The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted.The sulfoxides and sulfones could be obtained by simply switching the reaction media,i.e.,bis(2-butoxyethyl)ethe...The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted.The sulfoxides and sulfones could be obtained by simply switching the reaction media,i.e.,bis(2-butoxyethyl)ether(BBE)or poly(ethylene glycol)dimethyl ether(PEGDME).The application of the high-boiling-point polyether as an initiator and green media can eliminate the need of large quantities of additives and volatile solvents.This strategy represents an economic and eco-friendly method that could find potential applications.展开更多
Synthesis of symmetrical diaryl sulfoxides from arenes and thionyl chloride in the presence of a catalytic amount of iodine at room temperature under solvent-free conditions is described. Mild reaction conditions, eas...Synthesis of symmetrical diaryl sulfoxides from arenes and thionyl chloride in the presence of a catalytic amount of iodine at room temperature under solvent-free conditions is described. Mild reaction conditions, easy workup, high yield, and easily available catalyst are important features of this method.展开更多
Poly（4-vinylpyridinium tribromide） was prepared from poly（4-vinylpyridin） and used for the selective oxidation of a variety of sulfides to the corresponding sulfoxides. The oxidation reaction was carried out heter...Poly（4-vinylpyridinium tribromide） was prepared from poly（4-vinylpyridin） and used for the selective oxidation of a variety of sulfides to the corresponding sulfoxides. The oxidation reaction was carried out heterogeneously in acetone/water, as green solvent, at room temperature.展开更多
Zr（IV）-salen-MCM-41 was prepared by reaction of NH2-MCM-41 with salicylaldehyde to afford Schiff base ligands. Thereafter, ZrOCh.SH2O was reacted with the Schiff base ligands for complex formation. The structural pr...Zr（IV）-salen-MCM-41 was prepared by reaction of NH2-MCM-41 with salicylaldehyde to afford Schiff base ligands. Thereafter, ZrOCh.SH2O was reacted with the Schiff base ligands for complex formation. The structural properties of the synthesized materials were investigated by a number of analytical techniques including X-ray diffraction, N2 sorption-desorption, thermogravimetric analysis, Fourier transform infrared spectroscopy, inductively coupled plasma atomic emission spectroscpopy, and energy dispersive X-ray spectroscopy. Catalytic studies of the mesoporous materials functionalized with Zr（IV）-Schiff base complexes were investigated and extended to selective oxida- tion of sulfides to sulfoxides and the Knoevenagel condensation reactions of aldehydes with malo- nonitriles and ethyl cyanoacetate. Additionally, catalyst recycling of the Zr-salen-MCM-41 materials was also studied.展开更多
Hydroselenation of 1, 2-allenyl sulfoxides give 2-organoseleno substituted allyl sulfoxides in high yields and the reaction is absolute regioselective.
The adsorption of decylmethylsulfoxide(DEMS)onto carbon black and the effects of temperature,salt(NaCl)and acid (HCl)have been measured.Typical two plateaux type adsorption isotherms were obtained.Applying the two ste...The adsorption of decylmethylsulfoxide(DEMS)onto carbon black and the effects of temperature,salt(NaCl)and acid (HCl)have been measured.Typical two plateaux type adsorption isotherms were obtained.Applying the two step model of surfactant adsorption on solid/liquld interface and the general adsorption isotherm equation[9]the experimental results were interpreted qualitatively and quantitatively.展开更多
The synergistic extraction of uranium (VI) from nitric acid aqueous solution with a mixture of tri-n-butyl phosphate (TBP) and petroleum sulfoxides(PSO) in benzene was studied. It has been found that the maximum syner...The synergistic extraction of uranium (VI) from nitric acid aqueous solution with a mixture of tri-n-butyl phosphate (TBP) and petroleum sulfoxides(PSO) in benzene was studied. It has been found that the maximum synergistic extraction effect occurs where the molar ratio of PSO to TBP is one to two. The composition of the complex of synergistic extraction is UO2(NO3)2-TBP.PSO. The formation constant of the complex KTp=57.44.展开更多
基金financial support by the National Key Research and Development Program of China(No.2023YFC2907801)the Hunan Provincial Natural Science Foundation of China(No.2023JJ40760)the Scientific and Technological Project of Yunnan Precious Metals Laboratory,China(No.YPML-2023050276)。
文摘Bentonite is a necessary binder in producing pellets.Its excessive use reduces the iron grade of pellets and increases production costs.Minimizing bentonite dosage is essential for producing high-quality iron ore pellets.Addressing the gap in the application of organically-intercalated modified bentonite in the pelletizing field,this study introduces an innovative modification process for bentonite that employs the synergistic effect of mechanical force and dimethyl sulfoxide to enhance the intercalation of organic compounds within bentonite,thus significantly enhancing its binding performance.The colloid value and swell capacity of modified bentonite(98.5 m L/3g and 55.0 m L/g)were much higher than the original bentonite(90.5 m L/3g and 17.5 m L/g).With the decrease of bentonite dosage from1.5wt%to 1.0wt%,the drop number of green pellets from a height of 0.5 m and the compressive strengths of roasted pellets using the modified bentonite(6.0 times and 2916 N per pellet)were significantly higher than those of the original bentonite(4.0 times and 2739 N per pellet).This study provides a comprehensive analysis of the intercalation modification mechanism of bentonite,offering crucial technical insights for the development of high-performance modified bentonite as iron ore pellet binders.
文摘DBUH-Br_3 catalyzed selective conversion of sulfides to sulfoxides in the presence of H_2O_2 as oxidizing agent is described.The reaction was performed selectively at room temperature and relatively short reaction times.
文摘The recent development of selective oxidation of aromatic sulfides with molecular oxygen was highlighted.The sulfoxides and sulfones could be obtained by simply switching the reaction media,i.e.,bis(2-butoxyethyl)ether(BBE)or poly(ethylene glycol)dimethyl ether(PEGDME).The application of the high-boiling-point polyether as an initiator and green media can eliminate the need of large quantities of additives and volatile solvents.This strategy represents an economic and eco-friendly method that could find potential applications.
文摘Synthesis of symmetrical diaryl sulfoxides from arenes and thionyl chloride in the presence of a catalytic amount of iodine at room temperature under solvent-free conditions is described. Mild reaction conditions, easy workup, high yield, and easily available catalyst are important features of this method.
基金Financial support for this work by the Ilam University,Ilam,Iran is gratefully acknowledged
文摘Poly（4-vinylpyridinium tribromide） was prepared from poly（4-vinylpyridin） and used for the selective oxidation of a variety of sulfides to the corresponding sulfoxides. The oxidation reaction was carried out heterogeneously in acetone/water, as green solvent, at room temperature.
基金Financial support to this work by the Ilam University
文摘Zr（IV）-salen-MCM-41 was prepared by reaction of NH2-MCM-41 with salicylaldehyde to afford Schiff base ligands. Thereafter, ZrOCh.SH2O was reacted with the Schiff base ligands for complex formation. The structural properties of the synthesized materials were investigated by a number of analytical techniques including X-ray diffraction, N2 sorption-desorption, thermogravimetric analysis, Fourier transform infrared spectroscopy, inductively coupled plasma atomic emission spectroscpopy, and energy dispersive X-ray spectroscopy. Catalytic studies of the mesoporous materials functionalized with Zr（IV）-Schiff base complexes were investigated and extended to selective oxida- tion of sulfides to sulfoxides and the Knoevenagel condensation reactions of aldehydes with malo- nonitriles and ethyl cyanoacetate. Additionally, catalyst recycling of the Zr-salen-MCM-41 materials was also studied.
基金We ale grateful to the National Natural Science Foundation of China(Project No.20272050,20332060)for financial support.
文摘Hydroselenation of 1, 2-allenyl sulfoxides give 2-organoseleno substituted allyl sulfoxides in high yields and the reaction is absolute regioselective.
文摘The adsorption of decylmethylsulfoxide(DEMS)onto carbon black and the effects of temperature,salt(NaCl)and acid (HCl)have been measured.Typical two plateaux type adsorption isotherms were obtained.Applying the two step model of surfactant adsorption on solid/liquld interface and the general adsorption isotherm equation[9]the experimental results were interpreted qualitatively and quantitatively.
基金Supported by the National Natural Science Foundation of China (20171029)
文摘The synergistic extraction of uranium (VI) from nitric acid aqueous solution with a mixture of tri-n-butyl phosphate (TBP) and petroleum sulfoxides(PSO) in benzene was studied. It has been found that the maximum synergistic extraction effect occurs where the molar ratio of PSO to TBP is one to two. The composition of the complex of synergistic extraction is UO2(NO3)2-TBP.PSO. The formation constant of the complex KTp=57.44.
