A method to upgrade the iron grade in copper slag was proposed using lime to decompose Al_(2)O_(3)-containing fayalite melt(AFMT).Thermodynamic calculations indicated that adjusting the CaO/AFMT ratio can yield a resi...A method to upgrade the iron grade in copper slag was proposed using lime to decompose Al_(2)O_(3)-containing fayalite melt(AFMT).Thermodynamic calculations indicated that adjusting the CaO/AFMT ratio can yield a residual melt with a FeO concentration of 75−88 wt.%and produce Ca_(2)SiO_(4).In-situ observations suggested that the reaction was impeded in some way.Quenching experiments revealed that the initial reaction products consisted of calcium ferrite compounds and FeO−CaO melt.At the FeO−CaO melt/AFMT interface,Ca_(2)SiO_(4) particles precipitated,forming a dense Ca_(2)SiO_(4) film that significantly impeded mass transfer.Although trace amounts of Al_(2)O_(3) in AFMT temporarily enhanced mass transfer,they were insufficient to overcome this retardation effect.The decomposition reaction was far from achieving equilibrium,demonstrating a self-retardation effect.Measures must be implemented to eliminate this self-retardation effect and enhance the efficiency of reaction kinetics.展开更多
Coal ash melting characteristics has a direct impact on the smooth operation of entrained gasifier.Mineral conversion of coal ash is very significant to be investigated,because the mineral can affect the melting tempe...Coal ash melting characteristics has a direct impact on the smooth operation of entrained gasifier.Mineral conversion of coal ash is very significant to be investigated,because the mineral can affect the melting temperature and viscosity under high temperature conditions.In this paper,the effects of different Al2O3/CaO on the mineral conversion,melting temperature and viscosity of Ningdong coal ash are studied by the combination of experiment and simulation.The trend of melting temperature decreases firstly and rises with increasing Al_(2)O_(3)/CaO.The ashmelting point reached to the lowestwhen the ratio is 1.23.XRD and Factsage software are used to analyze crystallization behavior of samples.The results showthat the content of anorthite,albite and corundumincreases and subsequently decreases,while the content of mullite decreases firstly and then rises with increasing Al_(2)O_(3)/CaO.High content with CaO can contribute to form albite and anorthite of low-melting.Besides,high content with Al_(2)O_(3) can tend to produce mullite of high-melting.The results of experimental and simulation are basically the same,which lays a foundation for the melting characteristics of Ningdong coal ash and can provide technical support for the smooth operation of the entrained-gasifier.展开更多
B_(2)O_(3)-Zn O-SiO_(2)(BZS)glass containing Cu O with excellent acid resistance,wetting properties,and high-temperature sintering density was prepared by high temperature melting method and then applied in copper ter...B_(2)O_(3)-Zn O-SiO_(2)(BZS)glass containing Cu O with excellent acid resistance,wetting properties,and high-temperature sintering density was prepared by high temperature melting method and then applied in copper terminal electrode for multilayer ceramic capacitors(MLCC)applications.The structure and property characterization of B_(2)O_(3)-Zn O-SiO_(2)glass,including X-ray diffraction,FTIR,scanning electron microscopy,high-temperature microscopy,and differential scanning calorimetry,indicated that the addition of CuO improved the glass’s acid resistance and glass-forming ability.The wettability and acid resistance of this glass were found to be excellent when CuO content was 1.50 wt%.Compared to BZS glass,the CuO-added glass exhibited excellent wettability to copper powder and corrosion resistance to the plating solution.The sintered copper electrode films prepared using the glass with CuO addition had better densification and lower sintering temperature of 750℃.Further analysis of the sintering mechanism reveals that the flowability and wettability of the glass significantly impact the sintering densification of the copper terminal electrodes.展开更多
The mechanism of electroreduction olf molybdenun in molten KF-B_(2)O_(3)-K2MoO_(4) has been sttdied byrneuns of linear sweep voltammetry.cyclic voltammetry and chronopotentiometry.
基金supported by the National Natural Science Foundation of China (No.52121004)the National Science Fund for Distinguished Young Scholars (No.51825403)+2 种基金the Science and Technology Innovation Program of Hunan Province,China (No.2021RC3013)National Key R&D Program of China (No.2022YFC3901602)the Major Science and Technology Project of Gansu Province,China (No.21ZD4GD033)。
文摘A method to upgrade the iron grade in copper slag was proposed using lime to decompose Al_(2)O_(3)-containing fayalite melt(AFMT).Thermodynamic calculations indicated that adjusting the CaO/AFMT ratio can yield a residual melt with a FeO concentration of 75−88 wt.%and produce Ca_(2)SiO_(4).In-situ observations suggested that the reaction was impeded in some way.Quenching experiments revealed that the initial reaction products consisted of calcium ferrite compounds and FeO−CaO melt.At the FeO−CaO melt/AFMT interface,Ca_(2)SiO_(4) particles precipitated,forming a dense Ca_(2)SiO_(4) film that significantly impeded mass transfer.Although trace amounts of Al_(2)O_(3) in AFMT temporarily enhanced mass transfer,they were insufficient to overcome this retardation effect.The decomposition reaction was far from achieving equilibrium,demonstrating a self-retardation effect.Measures must be implemented to eliminate this self-retardation effect and enhance the efficiency of reaction kinetics.
基金supported by the Key Research and Development Program of Ningxia(2018BCE01004)Natural Science Foundation of Ningxia(2018AAC03013)Discipline Project of Ningxia(NXYLXK2017A04).
文摘Coal ash melting characteristics has a direct impact on the smooth operation of entrained gasifier.Mineral conversion of coal ash is very significant to be investigated,because the mineral can affect the melting temperature and viscosity under high temperature conditions.In this paper,the effects of different Al2O3/CaO on the mineral conversion,melting temperature and viscosity of Ningdong coal ash are studied by the combination of experiment and simulation.The trend of melting temperature decreases firstly and rises with increasing Al_(2)O_(3)/CaO.The ashmelting point reached to the lowestwhen the ratio is 1.23.XRD and Factsage software are used to analyze crystallization behavior of samples.The results showthat the content of anorthite,albite and corundumincreases and subsequently decreases,while the content of mullite decreases firstly and then rises with increasing Al_(2)O_(3)/CaO.High content with CaO can contribute to form albite and anorthite of low-melting.Besides,high content with Al_(2)O_(3) can tend to produce mullite of high-melting.The results of experimental and simulation are basically the same,which lays a foundation for the melting characteristics of Ningdong coal ash and can provide technical support for the smooth operation of the entrained-gasifier.
基金the National Natural Science Foundation of China(Nos.51372179,51772224)the Open Project Foundation of Guangdong Fenghua Advanced Technology(No.FHR-JS-202011024)。
文摘B_(2)O_(3)-Zn O-SiO_(2)(BZS)glass containing Cu O with excellent acid resistance,wetting properties,and high-temperature sintering density was prepared by high temperature melting method and then applied in copper terminal electrode for multilayer ceramic capacitors(MLCC)applications.The structure and property characterization of B_(2)O_(3)-Zn O-SiO_(2)glass,including X-ray diffraction,FTIR,scanning electron microscopy,high-temperature microscopy,and differential scanning calorimetry,indicated that the addition of CuO improved the glass’s acid resistance and glass-forming ability.The wettability and acid resistance of this glass were found to be excellent when CuO content was 1.50 wt%.Compared to BZS glass,the CuO-added glass exhibited excellent wettability to copper powder and corrosion resistance to the plating solution.The sintered copper electrode films prepared using the glass with CuO addition had better densification and lower sintering temperature of 750℃.Further analysis of the sintering mechanism reveals that the flowability and wettability of the glass significantly impact the sintering densification of the copper terminal electrodes.
基金supported by the National Natural Science Foundation
文摘The mechanism of electroreduction olf molybdenun in molten KF-B_(2)O_(3)-K2MoO_(4) has been sttdied byrneuns of linear sweep voltammetry.cyclic voltammetry and chronopotentiometry.
