The heating pipe of stainless-steel APT crystallizer cracks and leaks when heat conducting oil is used as its heating medium.Therefore,the causes of crack formation are analyzed by macroscopic examination,component analysis and parameter test.And it is pointed out that stress and Cl-from heat conducting oil are the main causes.Some specific measures to resolve the problem are suggested.

The basic requirements for tungsten wire from lighting industry are introduced.Eddy current crack detection is performed for D0.39 mm tungsten wire.Based on sampling crack detection defect part and observing microstructure,some typical defect types are summarized and their formation causes and influence factors are briefly analyzed.

A dinuclear Ni（Ⅱ） crown ether complex[Ni2（L）Cl2]·H2O is introduced,and H2L in the molecular formula is substituted for 3,7,11,19,23,27-hexaaza-33,34-dihydroxyl-15,31-dimethyl-tricycle-tetratriacontane-1（32）,13,15,17（34）,29（33）,30-hexaene anion.The complex is prepared through the reaction of the ligand H2L with NiCl2·6H2O,and it is characterized by element analysis,IR spectrum and single crystal XRD.The results show that the complex is in the monoclinic system and the space group C2/c with a=2.766 7（4） nm,b=0.844 40（3） nm,c=1.875 9（4） nm,β=129.65（2）°,V=3.374 4（9） nm3,Z=4,F（000）=154 4,Dc=1.439 g/cm3,R1=0.051 6,wR2=0.101 9 [I2σ（I）].The dinuclear structural units of the complex are connected through the hydrogen bond N-H…Cl to form a one-dimensional supramolecular chain structure.

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.