Study is made on the influences of direct acid leaching and black roasting-acid leaching on vanadium leaching behaviors of three kinds of carbonaceous shale from Xiushui or Pengzhe in Jiangxi province and Tongshan in Hubei province,respectively. The results show that under the conditions of leaching temperature 95 ℃ ,leaching time 4 h,mass ratio of liquid to solid 1 ： 1 ,volume fraction of H2SO4 15% ,mass fraction of CaF2 5 %,the vanadium leaching rates of three kinds of carbonaceous shale treated with direct acid leaching are 92. 39%, 74. 10%and 40. 53%, respectively, while the above leaching rates with black roasting-acid leaching are 85. 53%,90. 78% and 41.59%,respectively. It is found that both the existing forms of vanadium and iron in carbonaceous shale and the contents of acid-consumable minerals have great effects on vanadium leaching. By blank roasting, vanadium in organics can be transformed into free and soluble vanadium oxide, and mica-contained vanadium can be disintegrated to accelerate vanadium leaching. However,the acid-nonconsumable mineral of pyrite could be transformed into the acid-consumable mineral of hematite to hinder vanadium leaching. It is reasonable for the three kinds of carbonaceous shale in which vanadium exists mainly in the form of aluminosilicate including mica to adopt correspondingly different vanadium leaching processes. Direct acid leaching process is suitable for carbonaceous shale from Xiushui inJiangxi Province,blank roasting-acid leaching process is suitable for carbonaceous shale from Pengzhe in Jiangxi Province,and another vanadium extracting process should be adopted for carbonaceous shale from Tongshan in Hubei Province.

A new process was studied for the preparation of high-purity metal cerium with high-purity CeO2 as the raw material. The process of calcium-thermal reduction, vacuum melting,floating zone melting and solid-state electric migration is applied for preparation and refining of high-purity metal cerium,and the product has the relative purity of Ce/TREM≥99.99% and the absolute purity of 99. 961%. The process is applicable for the preparation of high-purity RE metallic reagent.

This paper presents a systematical study on a new process of tungsten recovery from tungsten slag. The tungsten leaching rate reaches more than 860/00 with 1% additive A,20% hydrochloric acid mass fraction, 100℃acid leaching temperature,3 h leaching time and 3 ： 1 liquid-solid ratio. Moreover,tungsten and other valuable metals could be well separated by ion exchange of weakly basic anion exchange resin and purification process. The process is characterized by reasonable product structure, high recovery, less inrcial operation and quick effect with very good industrial application prospect.

Volatile dust containing indium and other valuable metals is obtained by rotary kiln reduction vol atilization with blast furnace dust as the raw material. Indium ingot is produced through neutral leaching, two-stage acid leaching, extraction, stripping, metathesis reaction, electrolysis and casting process with total indium recovery up to 70 %. The process has been successfully used in the industrial practice with good economic benefit ,and its market prospect will be very broad.

After measurement of the resistance of molten salt with the AC impedance spectrum method,the electrical conductivity of Nd2O3-NdF3-LiF molten salt was tested by continuously varying cell constant （CVCC） technique. Meanwhile, the regression equations between the temperature, component of molten salt and its electrical conductivity were developed. The study is focused on the relations between the electrical conductivity and NdF3 content, and interaction between the ion concentration and the directional migration resistance of molten salt charge is analyzed. The results show that the electrical conductivity of the melt increases with the increase of temperature and LiF content,but decreases with increasing Nd2O3 and NdF3 content. At given temperature,the electrical conductivity of molten salt depends on the concentration of the ions and the resistance of directional migration of charge, especially on the resistance of directional migration of charge.

The main methods for preparing doped tungsten oxide are described, such as solid-phase method, liquid-phase method and gas-phase method. The advantages and disadvantages of these methods are summarized as well as their development prospect. Improvement effects of different element doping are analyzed on electrochromism performance, gas sensitivity and photocatalysis performance of tungsten oxide. And research direction for the functional properties of future doped tungsten oxide is proposed.

The main preparation technologies are introduced for ultrafine/nano WC-Co composite powders, such as liquid phase reduction method,oxidation-reduction method, sol-gel method, coprecipitation method and spray conversion method. The current research on spray conversion is expounded based on the research results of the authors, and its advantages are pointed out, such as short process, uniform distribution of powder components and nano-crystallization. However, some deeper theoretical researches are to be conducted ina spects of control of particle size and morphology,component migration and in-situ low-temperature reduction carbonization.

Molybdenum alloys with different Zr dosage were prepared by powder metallurgy,and the influences were studied of Zr dosage on the microstructure and properties of molybdenum alloy. The results show that the strengthening effects of Zr element on the molybdenum alloy are mainly reflected in two aspects：one is the second phase strengthening from the second phase oxide generated after Zr element added to Mo matrix,and the other is solution reinforcement and grain refinement both from Zr dissolved into Mo matrix. The tensile strength of all the Zr-doped molybdenum alloys is higher than pure molybdenum at room temperature,while their elongation is the opposite. Under the condition of Zr dosage 0.08%-0. 15%,the tensile strength of molybdenum alloy increases with the increase of Zr dosage,while the elongation increases at first and then decreases and reaches the maximum when Zr dosage is 0.19,%.

Fe-36Ni invar alloys with different Zr content were prepared by smelting in a carbon tube furnace. The effects of Zr addition and solidification conditions on alloy solidification mierostrueture were investigated by SEM and EDS,and then the mechanism of solidification microstructure improvement was analyzed. The results show that alloy solidification microstructure is obviously refined after Zr addition. With the increase of Zr content, refinement effect of the solidification microstructure becomes better. A large number of high-melting-point compound ZrO2 is formed and dispersed in the alloy after Zr addition. The lattice misfit between ZrO2 （0001） surface and Fe-36Ni （100） surface is low,so ZrO2 can serve as effective heterogeneous nucleation core to refine the solidification microstructure of the invar alloy. Under the condition of adding the same content of rare earth element Y, the solidification microstructure is remarkably re- fined with decreased casting temperature and increased cooling speed. When casting temperature exceeds 1 500℃, the effect of Y2O2 S as heterogeneous nucleation core disappears, and the solidification microstructure of the alloy is composed of complete columnar grains.

Eu3＋-doped YPO4 phosphors were synthesized via citric acid-assisted sol-gel process, and their crystal structure and fluorescence properties were investigated. The results show that both heat treatment temperature and heat treatment time have direct influence on phase structure of the products. During the heat treatment,the hexagonal YPO4 · 0.8H20 crystal is generated from xerogel before tetragonal YPO4 crystal is developed from the dehydration of YPO4 · 0.8H2O crystal. Emission spectra of the samples show that the synthesized Eu3＋-doped YPO4 can be effectively excited with 222 nm wavelength light, emittng intense orange-red light at 595 nm and 621 nm. Concentration quenching phenomenon occurs when Eu3＋ dosage is over 8% （molar fraction）. Furthermore,fluorescence properties can be effectively improved by in- creasing heat treatment temperature or prolonging heat treatment time.