The process of sump leaching with hydrochloric acid for two cycles was adopted to extract molybdenum oxide from a refractory molybdenum oxide ore produced in Inner Mongolia.The ore contains 1.20% Mo,and its particle size is 10~20 mm.The ratio of liquid to solid is controlled at 0.3 during leaching,and leaching duration of either cycle is 8 h.The HCl concentrations of leaching solutios are 200 g/L and 220 g/L,respectively for the first cycle and the second cycle.The results show that the average Mo leaching rate of the above process is 78.80%,the recovery of ammonia neutralization-precipitation process is 96.22%,and Mo content of the product is 43%.

A new process of vanadium extraction from alkali leach liquor of carbonaceous shale containing vanadium was studied.The process includes the four steps of silicon initial removal,vanadium alkali extraction,silicon washing removal and vanadium stripping.The results show that the silicon removal rate is up to 99.58% by controlling the final pH value at 9.5,keeping the ratio of organic phase（N263） to aqueous phase at 1/4,and employing Na2CO3 solution（pH=10） as the eluent.The process is simple,and both its vanadium recovery and separation efficiency of vanadium and silicon are high.

Experiments on the separation of rhenium from molybdenum were carried out with a macroporous alkalescence acrylic anion exchange regenerative resin（D314）.The absorption and desorption conditions of rhenium and molybdenum were studied.The results show that rhenium and molybdenum can be adsorbed together in the solution of pH4.0~7.0.Rhenium can be separated from molybdenum by first using the eluent of 8% NH3·H2O＋10% NH4NO3 to desorb molybdenum and then using 4% NH3·H2O to desorb rhenium.The above process is applied in rhenium separation from molybdenum of molybdenum ash,the obtained molybdenum can be used for preparing ammonium dodecamolybdate with a purity of 98.78%,and the trace rhenium is enriched by nearly 1 000 times,which provides favorable conditions for the downstream concentration extraction process.

The influences of condensation and evaporation area ratio,crystallization temperature and stirring rate were investigated on the concentration of the ammonia water resulting from ammonia tail gas condensation in the process of APT crystallization.The results show that both lower crystallization temperature and faster stirring rate can increase ammonia concentration of the recovered solution from crystallization ammonia tail gas.When the condensation and vaporization area ratio is 3.9 and the crystallization temperature is 110 ℃,the total ammonia concentration of the recovered solution is 9.9 mol/L.

NiCrAlCoY coating was obtained at room temperature on the carbon steel surface with a high-energy ball mill.SEM,EDS,XRD,microhardness test technique and high-temperature oxidation experiment were employed to investigate morphology,structure,microhardness and high-temperature oxidation resistance of the coating.Coating formation mechanism on substrate surface is discussed in the process of mechanical alloying.The results show that increasing ball rotation speed can improve the thickness,microhardness and high-temperature oxidation resistance of the coating.A 50 μm thick NiCrAlCoY coating combined well with substrate is formed by ball milling at 400 r/min for 10 h.The maximum microhardness（HV0.1） of the coating reaches 706,about three times as high as that of the substrate.Interface microhardness presents gradient variation,playing a good role in supporting the coating.And the high-temperature oxidation resistance of substrate is improved significantly in the presence of the coating.

Ternary Ni-Mo-Co alloy electrode was prepared by electrodeposition.The effects of deposition current density,and temperature and pH of electroplating solution were studied on the catalytic activity for hydrogen evolution reaction of the alloy electrode.The chemical composition and microstructure of the alloy electrode were investigated by EDS and XRD.Based on the polarization curves,the optimal technological conditions can be determined,including deposition current density 15 mA/cm2,temperature 25 ℃ and electroplating solution pH 10.Under the above conditions,the prepared alloy electrode is of amorphous structure,silver bright appearance,smooth and compact surface,and the chemical composition of 34.09% Ni,59.51% Mo and 6.40% Co.Meanwhile,its overpotential of hydrogen evolution in 30% KOH solution is 112 mV,that is 352 mV lower than that of Ni electrode,showing better catalytic activity for hydrogen evolution.

NbTiAlSi alloy with a density of 6.0 g/cm3 was prepared by vacuum consumable arc melting,and its microstructure was observed and analyzed by using optical microscope,scanning electron microscope and X-ray energy dispersive spectrometer.The results show that the alloy microstructure is composed of the two phases of（Nb,Ti）5Si3 and（Nb,X）SS（X represents such elements as Ti,Al,Cr and so on）.（Nb,Ti）5Si3 phase presents continuous net distribution with strip and block pattern.The sizes of（Nb,Ti）5Si3 strip and block cannot be changed significantly,but the distribution of the second phase of（Nb,Ti）5Si3 changes from continuous strip and block pattern to discontinuous block pattern by 1 400 ℃/9 h homogenization annealing treatment of alloy ingot.The tensile strength of the hot-rolled alloy reaches 704 MPa,and it presents the performance of tensile brittle fracture at room temperature.The brittleness of the alloy is caused by the characteristics of the M5Si3-type compounds and the micropores existing on the interface of the second phase and substrate of the hot-rolled alloy.

The latest development of different preparation technologies of YAG∶Ce3＋ yellow phosphor used in white LED is summarized.These technologies include solid reaction method,sol-gel method,spray method,flash combustion method,coprecipitation method,coprecipitation-molten salt method and so on.Their advantages and disadvantages are compared,and their development trends are also pointed out.

Y2O3∶Eu3＋ red phosphor was prepared by microwave radiation,and orthogonal experiments were carried out to determine the optimal technological conditions,where heating rate is 20 ℃/min,calcination temperature 1 240 ℃,and holding time 60 min.The sample prepared under the above conditions is of 107.0% relative brightness.The phase structure,granularity and spectra of the sample were analyzed,and the results show that the sample is composed of a single pure phase of Y2O3,and it has uniform particle size of D50=3.28 μm.The maximum peak in the emission spectrum of the sample locate at 607 nm,and the color coordinates of the sample are x=0.653 3、y=0.342 4.

The latest development of LaFe-based room temperature magnetic refrigerant materials is introduced in respect of their magnetocaloric effects and preparation technologies.It is indicated that NaZn13-tpye LaFe-based compound with high Fe content is an excellent soft magnetic material,and its Curie temperature can be improved by substituting Co for Fe and adding some nonmetal elements such as H,C and B.When LaFe-based compound is prepared by melt spinning and adding other lanthanon to replace La,its annealed time can be shortened to form NaZn13structure.The LaFe-based compound with an appropriate element ratio may be a room temperature magnetic refrigerant material with giant magnetocaloric effect.