Zirconium oxychloride was prepared from fused zirconia with the acid-alkali method. The effects were studied of fused zirconia-sodium hydroxide proportion, alkali fusion temperature and alkali fusion time on the conversion rate of zirconium during alkali fusion. The results show that the optimum conditions for alkali fusion are as follows ： mass ratio of fused zirconia to sodium hydroxide 1 ： 1,alkali fusion temperature 790 ℃ and alkali fusion time 1.5 h. Zirconium oxychloride prepared with the above method has a main grade of 36. 25%, Zr recovery rate reaches 91% ,Na2SiO3consumption reduces by more than 98% ,and alkali consumption can be reduced by 52%.

The pure Cr coatings were deposited on the surface of zirconium alloy by multi-arc ion plating technology. The effects of arc current on surface morphology, phase composition and interracial adhesion were analyzed by scanning electron microscopy （SEM） ,X-ray diffractometer （XRD） and scratch tester. Image J image processing software was used for statistics and analysis of the distribution of the micro particles in the surface of pure Cr coatings. The results show that with the increase of arc current, the size of microparticles in pure Cr coating surface increases firstly and then decreases,while the number of microparticles in the unit area decreases firstly and then increases. Meanwhile,preferred orientation of the pure Cr coatings changes from （110） crystal face to （200） crystal face, and interracial adhesion of pure Cr coatings to Zr alloy substrate decreases at first and then increases with the increase of arc current.

WC-6Co ultrafine cemented carbides were prepared at different sintering temperature and using the mixtures with different total carbon content （6.11%,6.13%,6.15%,6.17%, 6.19%, 6.21%,6.23% and 6.25%）. The magnetic properties and microstructure of the samples were analyzed, and the effects were studied of carbon content on WC grain growth activation energy of WC-6Co cemented carbides. The results show that with the increase of total carbon content,cobalt magnetism （Com） of the alloy sample is also gradually increased. For WC-6Co sintered at different temperature, corecive force （He） firstly increa- ses and then decreases,and WC grain size decreases at first and then increases with the increase of Com. When the Corn value is about 5 %, Hc reaches the maximum and WC grain size reaches the minimum. WC grain growth activation energy firstly increases and then decreases with Com increasing, and reaches the maximum when Corn is about 5.2%. With the increase of carbon content in a low range,more （Crx ,Vy）Cx carbide （a grain growth inhibitor） is generated on the WC grain surface. But with the further increase of carbon content,the production amount of （Crx, Vy）Cz carbide has reached the extreme value, while the temperature for generating liquid phase further declines and liquid volume dramatically increases, resulting in decreased WC grain growth activation energy.

Various factors influencing injection molding of WC-10Co ultrafine grained cemented carbide were studied. The processes of ball milling, injection, debinding and sintering were optimized. The results indicate that injection molding WC-10Co ultrafine grained cemented carbide sintered parts have the best performance after 1.0 h vacuum sintering at 1440 ℃ ,with cemented carbide grain size of 0. 465μm,density of 13.99 g/cm^3 and HRA hardness of 90.1.

On the basis of the formula of temperature rise caused by resistance Joule heat during EHM cutring process,cutting simulation tests were carried out using finite element analysis software DEFORM.and the cutting process was simulated of 45 steel by cemented carbide cutting tool with different current intensity. Temperature field of tool and tool-chip contact area and tool wear change rule with different current intensity were analyzed based on calculation. The results show that compared with the no-current cutting process.current input can reduce the tool temperature and tool wear,and with the current intensity increasing. the tool temperature is significantly reduced.

Research progress is reviewed on the electrochemical corrosion behavior of cemented carbide. The effects of the internal factors are emphatically analyzed such as grain size,bonding phase composition （Ni, Co and so on）,sintering process and added alloying elements （Cr,Ti,V,A1） on the electrochemical corrosion behavior of cemented carbides. The effects of the external factors are discussed such as working tem- perature, corrosive medium and surface treatment on the corrosion of cemented carbides. It is found that the effect of grain size is inconsistent in different corrosive media. The bonding phase Ni is more resistant to corrosion than Co,and reasonable sintering technology and appropriate addition of alloying elements can improve the corrosion resistance of cemented carbides. Compared with working temperature, the corrosive medium has more influence on the corrosion of cemented carbides, and different corrosive media lead to dif- ferent corrosion behavior and corrosion rate. The surface treatment of the cemented carbide can improve its corrosion resistance.

Alkaline extraction method with quaternary ammonium salt was proposed for deep removal of va- nadium from vanadium-containing ammonium tungstate solution and experimental research was carried out. The effects of organic phase composition and equilibrium aqueous pH on extraction were investigated as well as the effect of O/A ratio on stripping. Isotherms of extraction and stripping were plotted and the simulated multi-stage countercurrent extraction and stripping experiments were conducted. The results show that the concentration of vanadium in the aqueous phase drops below 10 mg/L and tungsten loss is below 5% after six-stage countercurrent extraction under the following conditions： organic phase composi- tion （volume fraction） of 1% N263, 5% 2-octanol and sulfonated kerosene,feed pH of 8.7 （by evaporation deamination pretreatment） ,phase ratio （O/A） of 1.25 ： 1 and 25 ℃. Vanadium in the loaded organic phase can be completely stripped with 2 mol/L NaOH solution,and the stripped organic phase can be returned to the extraction process for recycle.

Molybdenite microwave roasting process was studied. The main influencing factors and levels were determined by single factor experiments, and then the influences of roasting time, material weight and roasting temperature on roasting effect were studied by response surface methodology. The multiple re- gression equations were established for predicting MoO3 ratio and sulfur content and the technical parame- ters were optimized. The results show that roasting temperature, roasting time and material weight have obvious effect on roasting, and the level of influence is as follows：roasting temperature〉roasting time〉 material weight. Under the optimal conditions of 56.95 min roasting duration,8.33 g material and 649.55 ℃ roasting temperature,MoO3 ratio and sulfur content are 94.3% and 0. 054% respectively by microwave roasting, while MoO3 ratio and sulfur content are 85.5 % and 0. 471% respectively by traditional resistance furnace heating roasting. Microwave roasting greatly improves the molybdenite oxidation effect.

With 15 kA rare earth electrolytic cell as the research object,its temperature field was simulated by using the electro-thermal coupling module of COMSOL software,and the law was analyzed of tempera- ture distribution in the rare earth electrolytic cell. The results show that the transverse temperature distri- bution in the rare earth electrolysis cell is as follows：the region between the arc-shaped anode and its adja- cent cathode has the highest temperature,and the region between the cathode and the cathode has slightly lower temperature. The temperature rises at first and then declines from top to bottom along the vertical direction of the electrolytic cell.

To overcome the problem of inadequate utilization of Li resource in lithium-containing residue, Li2CO3 was prepared from lithium-containing residue by H2SO4 leaching, NaOH purification and EDTA deeply purification, and lithium precipitation with Na2 CO3. The results show that the optimal technological parameters are as follows： in the process of H2SO4 leaching, H2SO4 concentration of 5% （volume frac- tion） ,leaching temperature of 70 ℃ ,and leaching time of 60 min. In the process of NaOH purification and EDTA deeply purification,end pH of NaOH addition of 12 ,EDTA addition of 2.0 g/L;in the process of Li precipitation with Na2CO3 ,Li＋ concentration of 23 g/L in solution,Na2CO3 concentration of 300 g/L,and Na2CO3 dosage of 1. 10 times of the theoretical quantity, bath temperature of 95 ℃,reaction time of 40 min. With the optimal technological parameters, the indexes of Li2 CO3 products basically meet the require- ments of Li2CO3-0 level,and the comprehensive recovery rate of Li is over 95%.