The effects of raw materials on the formation of silicon oxide nanospheres by hydrothermal deposition were investigated using Si and SiO2 as the silicon sources. The results show that the mixture of Si and SiOe is the best raw material for preparing silicon oxide nanospheres by hydrothermal deposition, and thus the silicon oxide nanospheres with a small grain size and uniform size distribution can be obtained. Using Si alone as raw materials results in the formation of the spheric structure with a large grain size and wide size distribution. Even regular spheric structure cannot be obtained when the raw material is single SiO2. Therefore,SiO2 plays an important role in the formation of silicon oxide nanospheres.

Study is made on the influence of pressing density and sintering temperature on the electrical properties of a typical tantalum capacitor with 16 V/100 μF solid electrolyte using tantalum powder with a specific capacity of 30 000 μF ·V/g as the raw material. The results show that both the porosity and the specific capacity of Ta anode sheets decrease with the increase of pressing density. And the leakage current coefficient decreases down to a minimum of 4.5 × 10^-4 μA/（μF·V） at a pressing density of 5.5 g/cm^3. Furthermore,the increase of sintering temperature has resulted in less specific capacity, lower leakage current coefficient of Ta anode sheets and more product loss.

The present status of alkali autoclave process of tungsten minerals is described. A deep-processing technology of tungsten minerals for extracting tungsten was developed to optimize the process flowsheet of alkaline decomposition production. Upon taking some corresponding technical measures,the WO3 content in tungsten residue is only 1.0- 1.5%, and the overall recovery of tungsten minerals increases by 1-2 percentage points so that the tungsten resource is effectively utilized.

Three major influencing factors on charging stability during powder automatic compacting in cemented carbide production were discussed to provide reference for mixture compacting performance evaluation, press machine parameter or press technological parameter modification and the smooth realization of mass production.

In view of the importance of silver-based electrical contact material in electrical power system and electrical appliance industry, the progress in the research and application of the above material was summarized and discussed based on the literatures and research experience.

The mineral composition characterization of Ni-Mo ores is analyzed, the latest development of the treatment technology for Ni-Mo ores is reviewed, and the advantages and disadvantages are compared between hydrometallurgical process and pyrometallurgical process for Ni-Mo ores. It is pointed out that the hydrometallurgical process is superior in treating Ni-Mo ores over pyrometallurgical process. Some problems present in the existing metallurgical processes of Ni-Mo ores are also pointed out. Furthermore,the development trend of the treatment technology for Ni-Mo ores is prospected.

Brief description is made of the molybdenum resource overview and molybdenum main applications. Organic molybdenum-based materials are classified,and their present and future development is also reviewed.

Description is made of some traditional techniques of selenium separation and per anode slime,seleniferous acid mud and seleniferous scrap. And the new selenium such as oxidation, leaching, extraction and distillation are summarized.

In view of the preparation of ultrafine cemented carbide by high energy ball milling, the action and its mechanism of surfactants in ball milling medium are introduced, the latest development of surfactants in the ball milling process of ultrafine cemented carbide is summarized, and the research trend of surfactants in this field is also pointed out.