Tungsten oxides in different valence states were prepared by hydrogen reduction of yellow tung- sten at 660 ℃for different time,and their morphology and structure characteristics were observed and ana- lyzed. Nanometer W or WC powders were prepared by reducing WO3. The growth mechanism of nanome- ter powders during phase transformation was discussed. Effects of morphology and structure genetic char- acteristics of raw material powders on particle size uniformity of the products were analyzed. The selection of porous tungsten oxide powders of single-phase composition, high purity, fine and uniform particle size as the raw material is good for preparing fine and uniform nanometer W or WC powders.

Technical conditions were studied for cobalt leaching from iron ore tailings in citric acid-ammoni- um bifluoride system. The results of orthogonal experiments show that reaction temperature is the primary influencing factor of cobalt leaching rate, reaction time and ammonium bifluoride concentration are second- ary,and citric acid concentration is the last one. The more reaction time and ammonium bifluoride concen- tration, the higher cobalt leaching rate. The results of the further experiment to determine the optimal con- ditions show that cobalt leaching rate can reach 90.61% with 100 ℃ reaction temperature, 20 g/L citric acid concentration,40 g/L ammonium bifluoride concentration and 4.0 h reaction time.

Vanadium was recovered from vanadium-containing ceaching solution with high iron concentra- tion by reducing precipitating-redissolving process. The process steps of pre-neutralizing of leaching solu- tion,preparation and redissolving of vanadium acid concentrate and the influence factors of each link were investigated. The results show that this process can recover vanadium and prepare qualified Vz 05 , but the overall recovery rate of vanadium is relatively low.

Germanium was recovered from fly ash by ammonium fluoride-sulfuric acid leaching. In the process ,ammonium fluoride reacts with sulfuric acid to generate hydrogen fluoride as the destruction rea- gent of silica and calcium oxide in fly ash,sulfuric acid serves as the destruction reagent of magnesia,and sodium chlorate serves as the oxidant to oxidize Ge（ Ⅱ ） into Ge（Ig）,which can he dissolved into the leac- hing solution by sulfuric acid. Finally, germanium is precipitated with tannic acid. The above process has the advantages of high germanium recovery,low cost, low pollution and so on. Under the optimal technical conditions,the germanium recovery reaches 80.12% and the grade of resultant germanium concentrate is up to 4. 69%.

The characteristics of current mineral resources in China are described. The latest development of complex ore processing techniques is reviewed, focusing on molybdenum-containing mixed mineral and high iron nickel laterite ore. Professional teaching reform measures are put forward of promoting class by scien tific research experiments.

Al2O3 coating was prepared on the surface of γ-TiAl alloy by sol-gel method, and the high tem- perature oxidation kinetics of the alloy substrate and the coated sample was researched by isothermal oxi- dation experiment. The algorithm of the kinetic equation was derived, and the thermal stress between oxide film and substrate was estimated. The results show that the kinetics of the blank sample follows the cubic law in the preceding period of high temperature oxidation, but then follows the linear law. However,high temperature oxidation kinetics of the coated sample follows the linear law first and then the parabolic law. The oxidation rate constant of Al2O3 coated sample decreases by nearly 90% compared with the blank con- trol sample. Al2O3 coating can improve cyclic oxidation resistance of the alloy by reducing the thermal stress between oxide film and substrate.

Cast or heat treated La0.80Mg0.20（Ni0.94Co0.06）3.7 alloys were prepared to investigate effects of heat treatment on electrode cycling performance, phase composition and electrochemical corrosion behaviour of the alloys. The results from SEM and EDS analysis show that heat treatment will result in less Mg and Ni concentration difference between phases in the alloys. Compared with cast alloy, heat treated alloy has a more positive interphase corrosion mixed potential. The maximum interphase corrosion current density of cast alloy and heat treated alloy is 106.1 mA/g and 82.4 mA/g,respectively. After heat treatment, the al loy has better electrode cycling performance due to lower interphase electrochemical corrosion.

The sintered ZrO2-NieO3 sheets were prepared by doping graphite powders into material, and they were used as the cathode to prepare ZrNi alloy by direct eletro-deoxidation. Effects of graphite powders do- ping on morphology and composition of the sintered sheets and eletro-deoxidation reaction of the cathode were investigated. The results show that in the case of doping graphite powders, the sintered ZrO2-Ni2O3 sheets have more uniform particle size and higher porosity. Graphite powder doping can also improve ca- thodic electrolysis current and accelerate eletro-deoxidation reaction, and furthermore the content of ZrNi alloy phase in the electrolysis product is higher,with mass fraction up to 82%（from oxidation-weighing method） or 94.6% （from EDS microanalysis）.

Zr-Nb-N film was deposited on monocrystalline silicon wafer with RF magnetron sputtering method at different nitrogen partial pressure. The results from EDS, TEM and XRD analysis show that with the increase of nitrogen partial pressure, nitrogen content in the film increases but niobium content decreases. Meanwhile, fine grain structure coarsens, and the two phases of NbN and ZrN are separated from the single phase of Zr-Nb-N solid solution. Four-probe resistance meters and microhardness tester were used to characterize sheet resistance and microhardness of the film. The results show that with nitrogen partial pressure increasing, sheet resistance of the film declines,and microhardness increases first and then decreases.

The internal structure is not dense enough and the plastic performance is low for the conventional hot rolling molybdenum plate. Therefore, the main influencing factors and control methods of the plastic performance of molybdenum plate were studied based on the rolling forming quality analysis and control. The current hot rolling process was analyzed, and improvement program was put forward and then a con- trast test was carried out. The results show that both the density and plastic performance of molybdenum plate can be obviously improved by improving hot rolling process.