采用微波对矿石进行加热预处理,使得矿物被更好地解离,提高了磁铁矿的磁选精矿产率和精矿品位。结果表明,当微波功率达到3 k W时,磁铁矿的磁选精矿产率由未处理原矿时的44%提高到72%;磁选电流为2.0 A时,磁选精矿产率达到最大,为60%;且...采用微波对矿石进行加热预处理,使得矿物被更好地解离,提高了磁铁矿的磁选精矿产率和精矿品位。结果表明,当微波功率达到3 k W时,磁铁矿的磁选精矿产率由未处理原矿时的44%提高到72%;磁选电流为2.0 A时,磁选精矿产率达到最大,为60%;且经过微波加热处理的矿石在磁选后,其精矿产品品位较原矿(50.2%)提高了6%~8%。展开更多
The effect of activation properties of the precursors of zeolite directly prepared from kaolin influenced by microwave field and conventional heating was investigated.XRD,TG-DSC,FT-IR,SEM,particle size analysis,specif...The effect of activation properties of the precursors of zeolite directly prepared from kaolin influenced by microwave field and conventional heating was investigated.XRD,TG-DSC,FT-IR,SEM,particle size analysis,specific surface area(BET),pore size distribution(BJH)and N2 adsorption-desorption were discussed to determine the optimal activation temperature.It is concluded that the conversion of kaolin to metakaolin in the microwave field is at 500°C holding for 30 min,which is 100°C lower than that in conventional calcination and 90 min shorter,and the phase transition process of kaolin under the effect of microwave field is the same as that of conventional heating method.SEM analysis indicates that the particle size is more uniform and agglomeration appears slightly in the microwave field.The N2 adsorption-desorption isotherm,BET and BJH of kaolin indicate that the pore properties are almost invariable regardless of calcination route during the process of calcining kaolin into metakaolin.It indicates that microwave calcination is superior to conventional calcination in the activation pathway of kaolin.It is attributed to microwave heating relying on objects to absorb microwave energy and convert it into thermal energy,which can simultaneously and uniformly heat the entire substance.展开更多
Numerical simulation has been performed on the optical transmission enhancement properties of a one-dimensional Ag film single slit structure with grooves. The results show that the position,depth and number of the gr...Numerical simulation has been performed on the optical transmission enhancement properties of a one-dimensional Ag film single slit structure with grooves. The results show that the position,depth and number of the grooves have great influence on the optical transmission,and surface plasmon polariton and resonance mode are the primary factors. The maximal extinction ratio of 35.8 dB is achieved in the single slit structure by adjusting groove depth.展开更多
A compact two-dimensional(2-D)finite-difference time-domain(FDTD)method is proposed to calculate the resonant frequencies and quality factors of a partially loaded cavity that is uniform in the𝑧-direction and ...A compact two-dimensional(2-D)finite-difference time-domain(FDTD)method is proposed to calculate the resonant frequencies and quality factors of a partially loaded cavity that is uniform in the𝑧-direction and has an arbitrary cross section in the𝑥x–y𝑦plane.With the description of𝑧dependence by𝑘z,the three-dimensional(3-D)problem can be transformed into a 2-D problem.Therefore,less memory and CPU time are required as compared to the conventional 3-D FDTD method.Three representative examples,a half-loaded rectangular cavity,an inhomogeneous cylindrical cavity and a cubic cavity loaded with dielectric post,are presented to validate the utility and efficiency of the proposed method.展开更多
文摘采用微波对矿石进行加热预处理,使得矿物被更好地解离,提高了磁铁矿的磁选精矿产率和精矿品位。结果表明,当微波功率达到3 k W时,磁铁矿的磁选精矿产率由未处理原矿时的44%提高到72%;磁选电流为2.0 A时,磁选精矿产率达到最大,为60%;且经过微波加热处理的矿石在磁选后,其精矿产品品位较原矿(50.2%)提高了6%~8%。
基金Projects(51604135,51504116)supported by the National Natural Science Foundational of ChinaProject(YNWR-QNBJ-2018-323)supported by the Yunan Ten Thousand Talents Plan Young&Elite Talents Project,China。
文摘The effect of activation properties of the precursors of zeolite directly prepared from kaolin influenced by microwave field and conventional heating was investigated.XRD,TG-DSC,FT-IR,SEM,particle size analysis,specific surface area(BET),pore size distribution(BJH)and N2 adsorption-desorption were discussed to determine the optimal activation temperature.It is concluded that the conversion of kaolin to metakaolin in the microwave field is at 500°C holding for 30 min,which is 100°C lower than that in conventional calcination and 90 min shorter,and the phase transition process of kaolin under the effect of microwave field is the same as that of conventional heating method.SEM analysis indicates that the particle size is more uniform and agglomeration appears slightly in the microwave field.The N2 adsorption-desorption isotherm,BET and BJH of kaolin indicate that the pore properties are almost invariable regardless of calcination route during the process of calcining kaolin into metakaolin.It indicates that microwave calcination is superior to conventional calcination in the activation pathway of kaolin.It is attributed to microwave heating relying on objects to absorb microwave energy and convert it into thermal energy,which can simultaneously and uniformly heat the entire substance.
基金the Key Program of National Natural Science of China(Grant No.50734007)the Research Foundation from Ministry of Education of China (Grant No.208133)the Natural Science Foundation of Yunnan Province (Grant No.2007F005M)
文摘Numerical simulation has been performed on the optical transmission enhancement properties of a one-dimensional Ag film single slit structure with grooves. The results show that the position,depth and number of the grooves have great influence on the optical transmission,and surface plasmon polariton and resonance mode are the primary factors. The maximal extinction ratio of 35.8 dB is achieved in the single slit structure by adjusting groove depth.
基金by the National Natural Science Foundation of China under Grant No 50734007.
文摘A compact two-dimensional(2-D)finite-difference time-domain(FDTD)method is proposed to calculate the resonant frequencies and quality factors of a partially loaded cavity that is uniform in the𝑧-direction and has an arbitrary cross section in the𝑥x–y𝑦plane.With the description of𝑧dependence by𝑘z,the three-dimensional(3-D)problem can be transformed into a 2-D problem.Therefore,less memory and CPU time are required as compared to the conventional 3-D FDTD method.Three representative examples,a half-loaded rectangular cavity,an inhomogeneous cylindrical cavity and a cubic cavity loaded with dielectric post,are presented to validate the utility and efficiency of the proposed method.
