Photopromoted carbonylation of alkyl bromides with carbon monoxide or carbon dioxide catalyzed by copper salts can be carried out under ambient conditions （atmospheric pressure and room temperature） and the correspo...Photopromoted carbonylation of alkyl bromides with carbon monoxide or carbon dioxide catalyzed by copper salts can be carried out under ambient conditions （atmospheric pressure and room temperature） and the corresponding ester was produced. The yield and the selectivity of the ester can be improved greatly by addition of sodium phosphate.展开更多
The thermal behavior and kinetic parameters of the major exothermic decomposition reaction of the title compound in a temperature-programmed mode were studied by means of TG-DTG and DSC. The critical temperature of th...The thermal behavior and kinetic parameters of the major exothermic decomposition reaction of the title compound in a temperature-programmed mode were studied by means of TG-DTG and DSC. The critical temperature of thermal explosion was calculated. The effect of the title compound on the combustion characteristic of composition modifier double base propellant containing RDX was explored with a strand burner. The results show that the kinetic model function in differential forms, the apparent activation energy(E a) and the pre-exponential factor(A) of the major exothermic decomposition reaction are 3(1-α)[-ln(1-α)] 2/3, 190.56 kJ/mol and 10 13.39 s -1, respectively. The critical temperature of thermal explosion of the compound is 353.08 ℃. The kinetic equation of the major exothermic decomposition process of the title compound at 0.1 MPa could be expressed as dα/dT=10 14.65(1-α)[-ln(1-α)] 2/3 e -2.2920×104/T. As an auxiliary catalyzer, the title compound can help the main catalyzer of lead salt of 4-hydroxy-3,5-dinitropyridine to accelerate the burning rate and reduce the pressure exponent of RDX-CMDB propellant.展开更多
The electrochemical behaviour of copper electrode in molten NaCl-KCl-LaCl_3 has been investigated.The La-Cu alloy is formed at first and then the metallic lanthanum is deposited when the La^(3+)is reduced on the coppe...The electrochemical behaviour of copper electrode in molten NaCl-KCl-LaCl_3 has been investigated.The La-Cu alloy is formed at first and then the metallic lanthanum is deposited when the La^(3+)is reduced on the copper electrode.The technological conditions of preparing La-Cu alloy by consumable cathode have been dis- cussed.The La-Cu alloy contained lanthanum over 90wt% was obtained.The composition of alloy was LaCu_2 and La.The current efficiency was 85% and the recovery of lanthanum was near 90%.展开更多
In this study,for the first time,direct copper production from copper sulfide was carried out via direct electrochemical reduction method using inexpensive and stable molten borax electrolyte.The effects of current de...In this study,for the first time,direct copper production from copper sulfide was carried out via direct electrochemical reduction method using inexpensive and stable molten borax electrolyte.The effects of current density(100–800 mA/cm^2)and electrolysis time(15–90 min)on both the cathodic current efficiency and copper yield were systematically investigated in consideration of possible electrochemical/chemical reactions at 1200℃.The copper production yield reached 98.09%after 90 min of electrolysis at a current density of 600 mA/cm^2.Direct metal production was shown to be possible with 6 kWh/kg energy consumption at a 600 mA/cm2 current density,at which the highest current efficiency(41%)was obtained.The suggested method can also be applied to metal/alloy production from single-and mixed-metal sulfides coming from primary production and precipitated sulfides,which are produced in the mining and metallurgical industries during treatment of process solutions or wastewaters.展开更多
Copper（ Ⅱ ） resercyiic acid（CuRes） nanoparticles were synthesized by using reactive precipitation method with resorcylic acid and blue copperas as the raw material in a rotating packed bed. The sample obtained wa...Copper（ Ⅱ ） resercyiic acid（CuRes） nanoparticles were synthesized by using reactive precipitation method with resorcylic acid and blue copperas as the raw material in a rotating packed bed. The sample obtained was characterized by using X-ray diffraction（XRD）, transmission electron micrescopy（TEM）, Fourier transform infrared spectroscopy （FTIR）, thermo-gravimetric analyses （TG）, and element analysis. In addition, the catalytic activity of CuRes nanoparticles on the thermal decomposition of nitrocellulose-nitroglycerine（NC-NG） was also determined via DSC. The results show that the spherical nanoparticles with a diameter of 20 nm were obtained in ethanol solution. The peak temperature of the thermal decomposition of NC-NG-CuRes decreases by 3℃ compared with that of normal CuRes, and the decomposition enthalpy is increased by 735 J/g, and therefore, it is reasonable to assume that CuRes nanoparticles have a better catalytic activity.展开更多
An alternative metal/alloy production method,known as direct electrochemical reduction(DER),was introduced for the fabrication of CuNi alloys from mixed sulfides(Cu2S,NiS)under both galvanostatic and potentiostatic co...An alternative metal/alloy production method,known as direct electrochemical reduction(DER),was introduced for the fabrication of CuNi alloys from mixed sulfides(Cu2S,NiS)under both galvanostatic and potentiostatic conditions.The influences of the process parameters(e.g.,cell voltage and current)on the compositions of the reduced compounds were investigated to yield industrially desirable alloys,namely,CuNi10,CuNi20,and CuNi30.The electrochemical behaviors of Cu2S and NiS in CaCl2 melt were examined at a temperature of 1200°C via cyclic voltammetry(CV).Based on the CV results,the cathodic reduction of Cu2S occurred in one step and cathodic reductions of NiS occurred in two steps,i.e.,Cu2S?Cu for copper reduction and NiS?Ni3S2?Ni for nickel reduction.Galvanostatic studies revealed that it was possible to fabricate high-purity CuNi10 alloys containing a maximum sulfur content of 320×10-6 via electrolysis at 10 A for 15 min.Scanning electron microscopy along with energy-dispersive X-ray spectrometry and optical emission spectroscopy(OES)examinations showed that it was possible to fabricate CuNi alloys of preferred compositions and with low levels of impurities,i.e.,less than 60×10-6 sulfur,via DER at 2.5 V for 15 min.展开更多
A novel method is proposed to enhance the gasification and removal of copper from molten steel by adding ammonium salts or urea into molten steel under normal pressure.The decopperization experiments were conducted in...A novel method is proposed to enhance the gasification and removal of copper from molten steel by adding ammonium salts or urea into molten steel under normal pressure.The decopperization experiments were conducted in a molybdenum-wire resistance furnace at 1 873 K.The copper content of about 400 g of a mild steel was reduced from 0.49%(mass fraction,the same below) and 0.51% to 0.31% and 0.38% using 0.7 g of NHC1 and 0.5 g of(NH)COrespectively,while the copper content of the molten steel was reduced from 0.61%to 0.56% using 2.00 g of NHCONH.展开更多
The discharge of industrial effluent containing heavy metal ions would cause water pollution if such effluent is not properly treated.In this work,the performance of emerging nanofiltration(NF)like-forward osmosis(FO)...The discharge of industrial effluent containing heavy metal ions would cause water pollution if such effluent is not properly treated.In this work,the performance of emerging nanofiltration(NF)like-forward osmosis(FO)membrane was evaluated for its efficiency to remove copper ion from water.Conventionally,copper ion is removed from aqueous solution via adsorption and/or ion-exchange method.The engineered osmosis method as proposed in this work considered four commercial NF membranes(i.e.,NF90,DK,NDX and PFO)where their separation performances were accessed using synthetic water sample containing 100 mg·L-1 copper ion under FO and pressure retarded osmosis(PRO)orientation.The findings indicated that all membranes could achieve almost complete removal of copper regardless of membrane orientation without applying external driving force.The high removal rates were in good agreement with the outcomes of the membranes tested under pressuredriven mode at 1 MPa.The use of appropriate salts as draw solutes enabled the NF membranes to be employed in engineered osmosis process,achieving a relatively low reverse solute flux.The findings showed that the best performing membrane is PFO membrane in which it achieved N 99.4%copper rejection with very minimum reverse solute flux of<1 g·m-2·h-1.展开更多
The complexes of hydrous copper chloride and copper nitrate with 2-amino-4,6-dimethylpyrimidine(ADMP) were prepared via reflux in alcohol. The compositions of the complexes were identified as Cu(ADMP) 2Cl 2·2H 2O...The complexes of hydrous copper chloride and copper nitrate with 2-amino-4,6-dimethylpyrimidine(ADMP) were prepared via reflux in alcohol. The compositions of the complexes were identified as Cu(ADMP) 2Cl 2·2H 2O(b) and Cu(ADMP)(NO 3) 2·H 2O(c) by chemical and elemental analyses. The complexes were characterized by IR, XPS, 1H NMR and TG-DTG techniques. The constant-volume combustion energies of ADMP and the complexes, Δ c E , were determined by a precise rotating-bomb calorimeter at 298 15 K. They were (-3664 53±1 18), (-4978 47±2 72) and (-1696 70±1 36) kJ/mol, respectively. Their standard enthalpies of combustion, Δ c H 0 m, and standard enthalpies of formation, Δ f H 0 m, were calculated to be (-3666 39±1 18), (-4977 23±2 72), (-1691 12±1 36) kJ/mol and (19 09±1 43), (-2041 80±3 29), (-2397 24±1 65) kJ/mol, respectively.展开更多
Copper oxides were prepared by direct heating and decomposing copper(Ⅱ) salts, such as Cu 2(OH) 2CO 3, Cu(NO 3) 2·3H 2O, Cu 2C 6H 4O 7·2 5H 2O, CuC 2O 4·2H 2O and CuAc 2·H 2O. The phase, surface a...Copper oxides were prepared by direct heating and decomposing copper(Ⅱ) salts, such as Cu 2(OH) 2CO 3, Cu(NO 3) 2·3H 2O, Cu 2C 6H 4O 7·2 5H 2O, CuC 2O 4·2H 2O and CuAc 2·H 2O. The phase, surface area and catalytic activity of the oxides for H 2O 2 decomposition were investigated by means of XRD and BET measurements. It has been demonstrated that the characteristics of copper oxides obtained from different precursors are much different from each other. Monocomponent nano CuO, which has higher catalytic activity for H 2O 2 decomposition, can be prepared by direct heating and decomposing Cu 2(OH) 2CO 3. On the other hand, CuO in the decomposition products of the organic acid copper can be partially reduced to Cu 2O and Cu in the reducing atmosphere, and the Cu 2O component in the products has higher catalytic activity for H 2O 2 decomposition.展开更多
基金the National Natural Science Foundation of China(No.20372012)for the generous financial support.
文摘Photopromoted carbonylation of alkyl bromides with carbon monoxide or carbon dioxide catalyzed by copper salts can be carried out under ambient conditions （atmospheric pressure and room temperature） and the corresponding ester was produced. The yield and the selectivity of the ester can be improved greatly by addition of sodium phosphate.
文摘The thermal behavior and kinetic parameters of the major exothermic decomposition reaction of the title compound in a temperature-programmed mode were studied by means of TG-DTG and DSC. The critical temperature of thermal explosion was calculated. The effect of the title compound on the combustion characteristic of composition modifier double base propellant containing RDX was explored with a strand burner. The results show that the kinetic model function in differential forms, the apparent activation energy(E a) and the pre-exponential factor(A) of the major exothermic decomposition reaction are 3(1-α)[-ln(1-α)] 2/3, 190.56 kJ/mol and 10 13.39 s -1, respectively. The critical temperature of thermal explosion of the compound is 353.08 ℃. The kinetic equation of the major exothermic decomposition process of the title compound at 0.1 MPa could be expressed as dα/dT=10 14.65(1-α)[-ln(1-α)] 2/3 e -2.2920×104/T. As an auxiliary catalyzer, the title compound can help the main catalyzer of lead salt of 4-hydroxy-3,5-dinitropyridine to accelerate the burning rate and reduce the pressure exponent of RDX-CMDB propellant.
文摘The electrochemical behaviour of copper electrode in molten NaCl-KCl-LaCl_3 has been investigated.The La-Cu alloy is formed at first and then the metallic lanthanum is deposited when the La^(3+)is reduced on the copper electrode.The technological conditions of preparing La-Cu alloy by consumable cathode have been dis- cussed.The La-Cu alloy contained lanthanum over 90wt% was obtained.The composition of alloy was LaCu_2 and La.The current efficiency was 85% and the recovery of lanthanum was near 90%.
文摘In this study,for the first time,direct copper production from copper sulfide was carried out via direct electrochemical reduction method using inexpensive and stable molten borax electrolyte.The effects of current density(100–800 mA/cm^2)and electrolysis time(15–90 min)on both the cathodic current efficiency and copper yield were systematically investigated in consideration of possible electrochemical/chemical reactions at 1200℃.The copper production yield reached 98.09%after 90 min of electrolysis at a current density of 600 mA/cm^2.Direct metal production was shown to be possible with 6 kWh/kg energy consumption at a 600 mA/cm2 current density,at which the highest current efficiency(41%)was obtained.The suggested method can also be applied to metal/alloy production from single-and mixed-metal sulfides coming from primary production and precipitated sulfides,which are produced in the mining and metallurgical industries during treatment of process solutions or wastewaters.
基金the National Natural Science Foundation of China(No 20576128)partially supported by the Natural ScienceFoundation of Shanxi Province(No 20051015)
文摘Copper（ Ⅱ ） resercyiic acid（CuRes） nanoparticles were synthesized by using reactive precipitation method with resorcylic acid and blue copperas as the raw material in a rotating packed bed. The sample obtained was characterized by using X-ray diffraction（XRD）, transmission electron micrescopy（TEM）, Fourier transform infrared spectroscopy （FTIR）, thermo-gravimetric analyses （TG）, and element analysis. In addition, the catalytic activity of CuRes nanoparticles on the thermal decomposition of nitrocellulose-nitroglycerine（NC-NG） was also determined via DSC. The results show that the spherical nanoparticles with a diameter of 20 nm were obtained in ethanol solution. The peak temperature of the thermal decomposition of NC-NG-CuRes decreases by 3℃ compared with that of normal CuRes, and the decomposition enthalpy is increased by 735 J/g, and therefore, it is reasonable to assume that CuRes nanoparticles have a better catalytic activity.
文摘An alternative metal/alloy production method,known as direct electrochemical reduction(DER),was introduced for the fabrication of CuNi alloys from mixed sulfides(Cu2S,NiS)under both galvanostatic and potentiostatic conditions.The influences of the process parameters(e.g.,cell voltage and current)on the compositions of the reduced compounds were investigated to yield industrially desirable alloys,namely,CuNi10,CuNi20,and CuNi30.The electrochemical behaviors of Cu2S and NiS in CaCl2 melt were examined at a temperature of 1200°C via cyclic voltammetry(CV).Based on the CV results,the cathodic reduction of Cu2S occurred in one step and cathodic reductions of NiS occurred in two steps,i.e.,Cu2S?Cu for copper reduction and NiS?Ni3S2?Ni for nickel reduction.Galvanostatic studies revealed that it was possible to fabricate high-purity CuNi10 alloys containing a maximum sulfur content of 320×10-6 via electrolysis at 10 A for 15 min.Scanning electron microscopy along with energy-dispersive X-ray spectrometry and optical emission spectroscopy(OES)examinations showed that it was possible to fabricate CuNi alloys of preferred compositions and with low levels of impurities,i.e.,less than 60×10-6 sulfur,via DER at 2.5 V for 15 min.
基金supported by the National Foundation of Natural Science of China
文摘A novel method is proposed to enhance the gasification and removal of copper from molten steel by adding ammonium salts or urea into molten steel under normal pressure.The decopperization experiments were conducted in a molybdenum-wire resistance furnace at 1 873 K.The copper content of about 400 g of a mild steel was reduced from 0.49%(mass fraction,the same below) and 0.51% to 0.31% and 0.38% using 0.7 g of NHC1 and 0.5 g of(NH)COrespectively,while the copper content of the molten steel was reduced from 0.61%to 0.56% using 2.00 g of NHCONH.
基金the financial support provided by the Malaysian Ministry of Education(Mo E)under the Fundamental Research Grant Scheme(Grant No.R.J130000.7851.5F017)Universiti Teknologi Malaysia(UTM)under the UTMSHINE Signature Grant(Grant No.Q.J130000.2451.07G79).
文摘The discharge of industrial effluent containing heavy metal ions would cause water pollution if such effluent is not properly treated.In this work,the performance of emerging nanofiltration(NF)like-forward osmosis(FO)membrane was evaluated for its efficiency to remove copper ion from water.Conventionally,copper ion is removed from aqueous solution via adsorption and/or ion-exchange method.The engineered osmosis method as proposed in this work considered four commercial NF membranes(i.e.,NF90,DK,NDX and PFO)where their separation performances were accessed using synthetic water sample containing 100 mg·L-1 copper ion under FO and pressure retarded osmosis(PRO)orientation.The findings indicated that all membranes could achieve almost complete removal of copper regardless of membrane orientation without applying external driving force.The high removal rates were in good agreement with the outcomes of the membranes tested under pressuredriven mode at 1 MPa.The use of appropriate salts as draw solutes enabled the NF membranes to be employed in engineered osmosis process,achieving a relatively low reverse solute flux.The findings showed that the best performing membrane is PFO membrane in which it achieved N 99.4%copper rejection with very minimum reverse solute flux of<1 g·m-2·h-1.
基金Supported by the Education Ministry Foundation of Shaanxi Province(No.HF0 130 4 )
文摘The complexes of hydrous copper chloride and copper nitrate with 2-amino-4,6-dimethylpyrimidine(ADMP) were prepared via reflux in alcohol. The compositions of the complexes were identified as Cu(ADMP) 2Cl 2·2H 2O(b) and Cu(ADMP)(NO 3) 2·H 2O(c) by chemical and elemental analyses. The complexes were characterized by IR, XPS, 1H NMR and TG-DTG techniques. The constant-volume combustion energies of ADMP and the complexes, Δ c E , were determined by a precise rotating-bomb calorimeter at 298 15 K. They were (-3664 53±1 18), (-4978 47±2 72) and (-1696 70±1 36) kJ/mol, respectively. Their standard enthalpies of combustion, Δ c H 0 m, and standard enthalpies of formation, Δ f H 0 m, were calculated to be (-3666 39±1 18), (-4977 23±2 72), (-1691 12±1 36) kJ/mol and (19 09±1 43), (-2041 80±3 29), (-2397 24±1 65) kJ/mol, respectively.
文摘Copper oxides were prepared by direct heating and decomposing copper(Ⅱ) salts, such as Cu 2(OH) 2CO 3, Cu(NO 3) 2·3H 2O, Cu 2C 6H 4O 7·2 5H 2O, CuC 2O 4·2H 2O and CuAc 2·H 2O. The phase, surface area and catalytic activity of the oxides for H 2O 2 decomposition were investigated by means of XRD and BET measurements. It has been demonstrated that the characteristics of copper oxides obtained from different precursors are much different from each other. Monocomponent nano CuO, which has higher catalytic activity for H 2O 2 decomposition, can be prepared by direct heating and decomposing Cu 2(OH) 2CO 3. On the other hand, CuO in the decomposition products of the organic acid copper can be partially reduced to Cu 2O and Cu in the reducing atmosphere, and the Cu 2O component in the products has higher catalytic activity for H 2O 2 decomposition.
