MIBK has different extraction performance for Sb（Ⅲ）and Sb（Ⅴ）under certain acidity condition.Therefore,high purity niobium oxide（Sb content10×10^-6）can be obtained by controlling certain acidity and oxidizing Sb（Ⅲ）into Sb（Ⅴ）in the extraction system of HF-H2SO4-MIBK to meet the requirements of Sb extraction separation to the maximum extent.

Niobium metal production process by carbon reduction is briefly introduced,focusing on development of reduction equipment to large capacity,energy saving,intelligent control and so on.The development of reduction equipment results in more niobium strip installed furnace capacity,less power consumption and better automation level to improve the competitiveness of carbon reduction process in the field of metal niobium production.

Theφ-pH diagrams of acid decomposition process of oxides of cerium and terbium at 298.15 K were studied by thermodynamic calculation.The results show that CeO2 and TbO2are difficult to be directly decomposed by acid,but they can be transformed into Ce^3＋and Tb^3＋by acid decomposition in a reductive environment.Compared with CeO2 and TbO2,Ce2O3 and Tb2O3can be directly decomposed into Ce^3＋and Tb^3＋by acid with high pH value,which actualizes the extraction of cerium and terbium.

The new technologies of membrane separation methods and electrochemical-adsorptive methods for development of salt lake lithium resources are reviewed.The technical principles,advantages and disadvantages,and current research status of each method are also expounded,and the development prospects of the methods of extracting lithium from the salt lake brines in China are proposed.

Indium was recovered from zinc oxide flue dust by two stage leaching and solvent extraction,and technical conditions of two stage leaching were investigated.The test results show that the low acidity condition has a good selectivity for Zn and In leaching from zinc oxide flue dust,and zinc is selectively leached into the solution and indium is concentrated in the residue.The optimal conditions of low acid leaching to remove Zn are as follows：leaching temperature of 60 ℃,liquid to solid ratio of 10∶1,sulfuric acid concentration of 0.16mol/L and leaching duration of 30 min.Under the above conditions,Zn leaching rate reaches93.73% and In content reaches 1 254g/t in the leaching residue.The optimal conditions of high acid leaching to recover In are as follows：leaching temperature of 70℃,liquid to solid ratio of 6∶1,H2SO4 concentration of 0.8mol/L and leaching time of 2h.Under the above conditions,In leaching rate is 89.32%.

In view of large amount of tellurium and bismuth enriched in bismuth refined alkaline residue,a process is proposed of tellurium and bismuth recovery from the alkaline residue.Tellurium exists in the alkaline residue mainly in the form of sodium tellurite.Sodium tellurite is soluble in water and transforms into tellurium dioxide near neutral pH value.Therefore,tellurium can be recovered to prepare coarse tellurium dioxide from the alkaline residue by primary process steps of water leaching,neutralization,roasting and so on.Feasibility of tellurium recovery from the alkaline residue was verified,and the influences were emphatically investigated of leaching time,liquid-solid ratio and neutralization pH value for tellurium precipitation on tellurium recovery.The results show that the optimum conditions are as follows：leaching time of5 h,liquid-solid ratio of 5∶1and neutralization pH value of 6.0for tellurium precipitation.

Introduction is made of Kaldor furnace process,semi-hydrometallurgical process and hydrometallurgical process widely applied for copper anode slime treatment at home and abroad.these processes are compared from process flowsheet,enrichment direction of main impurities and main existing problems,and then some suggestions are proposed on selection of copper anode slime treatment processes,and the future development direction is also pointed out.

ZrO2-doped tungsten alloy powders were prepared with step hydrothermal method combined with calcination and two-stage hydrogen reduction process using APT and zirconium nitrate as raw materials.Phase composition,morphology and phase transformation were analyzed of the products from different preparation process by XRD,EDS,SEM and TEM.The results show that a tungstenic acid of 1.5WO3·2H2O is generated in the hydrothermal reaction of APT and nitric acid,and monoclinic ZrO2 is generated in the hydrothermal reaction of zirconium nitrate and ammonia.The above products were uniformly mixed by liquid-liquid doping and dried to obtain the precursor powders.After calcination of the precursor powders at500-550 ℃,cubic 1.5WO3·2H2O transforms into monoclinic WO3.After 800 ℃×2h＋900 ℃×2hhydrogen reduction,ZrO2-doped tungsten alloy powders were obtained with average particle size of 10-20nm.Based on the results of contrast experiments,it is concluded that doping ZrO2 can play a role in refinement of tungsten grains.

Fe-Cr-C-Nb hardfacing alloy was prepared on the surface of 45 steel by open arc surfacing weding witn self-shielding flux-cored welding wires.The effect of ferroniobium content on microstructure,hardness and wear resistance of Fe-Cr-C-Nb hardfacing alloy was studied by using OM,SEM,XRD,Rockwell hardness tester and wear testing machine.The results show that the microstructure of Fe-Cr-C-Nb hardfacing alloy is composed ofγ-Fe、NbC、M7C3、M3C and a littleα-Fe.With the increase of Nb content,NbC precipitates have increased total amount and disperse uniformly in the matrix,with morphology evolution from granular to dendritic,and the growth ofγ-Fe particles is inhibited to refine the grains,and improve toughness and strength of Fe-Cr-C-Nb hardfacing alloy.The experimental results of hardness and wear resistance tests show that with the increase of Nb content,the hardness of Fe-Cr-C-Nb hardfacing alloy increases,and its wear resistance increases at first and then decreases.

In order to find the suitable annealing temperature of La0.62Y0.2Mg0.18Ni3.30Al0.20 alloy with excellence gaseous hydrogen absorption and desorption performance,phase composition and metallographic microstructure of the as-cast and annealed alloy were analyzed by XRD and OM,surface morphology of alloy particles before and after hydrogen absorption and desorption was observed by SEM,and PCT characteristics and dynamic performance of hydrogen absorption and desorption of the alloy were tested by pressurecomponent-temperature（PCT）apparatus.The results show that annealed alloy at 900℃contains the main phases of LaNi5and（La,Y,Mg）2（Ni,Al）7and Ni3 Y residual phase.With annealing temperature increasing,the main phases are unchanged but Ni3 Y phase is transformed into Y2Ni7 phase,and its cell volume increases at first and then decreases and FWHM firstly decreases and then increases within 41-43°diffraction angle.Compared with the as-cast alloy and the annealed alloy at 900℃,1 000℃and 1 050℃,the annealed alloy at 950 ℃ has better microstructure uniformity,and higher capacity and average velocity and smaller hydrogen pressure and hysteresis coefficient of hydrogen absorption and desorption.Based on comprehensive comparison,the suitable annealing temperature is 950 ℃for the alloy in our experiments.