Cr-doped APT powders were prepared by doping chromium acetate during ammonium paratungstate crystallization,and then their physicochemical properties were studied.The results show that the impurity elements are in line with the standard of APT-0in GB/T 10116—2007(Ammonium Paratungstate)except for chromium element.Chromium exists in APT powders mainly in the form of amorphous chromium hydroxide.As growth of APT crystal is inhibited by amorphous chromium hydroxide precipitated before APT,Cr-doped APT has smaller particle size,lower bulk density and slightly wider particle size distribution than ordinary Cr-free products.Cr-doped APT powders have macroscopically and microscopically uniform composition.

Scandium was extracted and recovered from the acid leaching solution of tungsten residue with primary amine N1923 as the extractant.The effects were studied of solution acidity,extractant volume fraction,phase ratio and extraction time on scandium extraction as well as the effect of hydrochloric acid concentration on scandium stripping.The results show that the extractant of primary amine N1923 has a good selectivity to scandium.The optimum conditions for extraction are as follows:solution acidity 0.25mol/L,extractant volume fraction 10%,O/A phase ratio 1∶1,and extraction time 5min.The proper stripping agent is 3.5mol/L dilute hydrochloric acid.Under the above optimum conditions,the extraction rate of scandium reaches 96.42%,the stripping rate is 98.28%,and the total recovery rate of scandium extraction is 92.33%.

时光荏苒,岁月如歌,历经六十载的砥砺磨练,长沙有色冶金设计研究院有限公司迎来了甲子华诞。六十年前,新中国成立之初,国家一穷二白,百废待兴。国家'一五'计划发轫,加快工业化建设的步伐。

ScB2was prepared by carbon thermal reduction in vacuum at high temperature with Sc2O3,B4 C and C powder as the raw materials.Qualitative and quantitative analysis was made of product phase composition by XRD and Rietveld whole pattern fitting.The results show that ScB2 synthesis rate can be more than 99% by carbon thermal reduction with Sc2O3 and B4C as the raw materials and appropriate amount of C powder as the reactive agent.

YB2powders were prepared by vacuum solid state reaction of YB4 and Y mixed compacts.Process conditions of solid state reaction were studied.The results show that high-purity YB2 powders can be obtained by vacuum solid state reaction at 1 800 ℃for 10 h.

W-Cu composite powders were prepared by hydrothermal synthesis with sodium tungstate and cupric nitrate as the raw materials.The recovery rate was calculated of W-Cu composite powders prepared at different pH.Preparation process of the precursor of W-Cu composite powders was analyzed based on thermodynamics.Phase composition,morphology and microstructure of the prepared W-Cu composite powders were characterized by XRD,SEM,EDS and TEM.The results show that the recovery rates of W and Cu ions are different at different solution concentration and pH value.When sodium tungstate concentration is 0.6mol/L,cupric nitrate concentration is 0.578 6 mol/L and the pH value is 5.5,W and Cu ions precipitate in the form of CuWO4·2H2O,and their recovery rates are more than 99%.The product of hydrothermal synthesis has good dispersivity and uniform particle size of 15~20nm.After calcined at 500℃and reduced with hydrogen at 800℃for 60 min,W-Cu composite powders are obtained with well-distributed W and Cu elements,subglobose microstructure of W-covered Cu and particle size of 100~200nm.

WC reinforced Fe-based composite was prepared by hot pressing sintering with two kinds of Febased pre-alloyed powders of EXD602 and EXDNi105and WC powder as the raw materials.The effects were investigated of different WC content and alloy matrix on microstructure and properties of the composite.The results show that the hardness,density and wear resistance of WC-EXD602 composite are much higher than those of WC-EXDNi105.With the increase of WC content,both hardness and density of WCEXD602 and WC-EXDNi105 composites increase firstly and then decrease,while wear loss decreases firstly and then increases.When the content of WC is 30%,peak hardnesses of WC-EXD602 and WC-EXDNi105 are HRA64.8and HRA48.6,respectively,and the porosity is the lowest.When the content of WC is 45%,wear loss of the two composites is the lowest.WC and alloy matrix alternately frictionize throughout wear process,and the main wear mechanism is abrasive wear.There is no obvious passivation phenomenon in the corrosion polarization curves of WC-EXD602 and WC-EXDNi105 samples.The descending order of the above composites according to their corrosion resistance is as follows:15WC-EXD602>15WC-EXDNi105>75WC-EXDNi105>75WC-EXD602.With WC content increasing,the corrosion resistance of the composites decreases in 3.5% NaCl solution.

WO3and TiO2 thin films were prepared on ITO coated glass substrate by DC magnetron sputtering with sputtering pressure as the variable.And then Li+polymer electrolyte was coated between the two films to assemble solid state electrochromic devices.Phase composition and surface morphology of WO3 thin film were characterized by XRD and AFM.Electrochromic performance of the devices was investigated with DC regulated power supply,and their colored/bleached state transmittance of visible light was determined by spectrophotometer.The results indicate that WO3 film deposited at 1.5Pa contains W metal.Amorphous state WO3 film is achieved at the sputtering pressure of 2.0~3.0Pa.WO3 film deposited at 2.0Pa has long and narrow particle clusters distributed on the surface and relatively large surface area benefiting injection/ejection of Li+and electron during coloration/bleaching,and thus its packaged device achieves the largest modulation amplitude and the fastest response.As sputtering pressure increasing,WO3 films have more surface defects resulting in the electrochromic performance of the devices worsened.

Molten salt electrolysis was done on V-Ti-Fe alloy prepared by metallothermic reduction,and deoxidation process of the alloy was studied.The influence of electrolysis time on deoxidation degree was investigated.The results show that most of oxygen in V-Ti-Fe alloy can be removed by molten salt electrolysis.With the increase of electrolysis time,oxygen content in the alloy gradually decreases to about 0.2%after 240 min electrolysis.Hydrogen absorption and desorption performances of V-Ti-Fe alloy are improved by electro-deoxidation in molten salt.With the increase of electrolysis time,both the maximum hydrogen absorption capacity and the effective hydrogen desorption capacity increase as high as 2.65% and 1.01%,respectively.

The development of several types of hydrogen storage alloys is reviewed,including AB5-type rare earth series hydrogen storage alloy,AB3-type hydrogen storage alloy,AB2-type Laves phase alloy,AB-type Ti series hydrogen storage alloy,Mg-based hydrogen storage alloy,V-based solid solution type hydrogen storage alloy and so on.The development orientation of hydrogen storage alloy is also forecasted.