Based on different process programs,the effects of rolling temperature,pass deformation rate and rolling rate on the structure and rolling yield of the pure molybdenum plate with a large single weight and a size of 72 mm×450 mm×320 mm were studied during cogging rolling.And the causes of the microcrack in molybdenum plates were analyzed.The results showed that there are microcracks caused in rolled pieces during cogging rolling,when the cogging temperature is lower than 1 350 ℃,average pass deformation rate above 21.5% and rolling rate lower than 48 m/min.And these microcracks extend with decreased heating temperature during later rolling.The optimum cogging temperature,average pass deformation rate and rolling rate should be controlled in the ranges of 1 450～1 500 ℃,20%～22%,48～53 m/min,respectively.

The characteristics of fluorine washing from tantalum and niobium hydroxide are analyzed.A recycling process of the washing water is studied and applied,resulting in more than 50% decrease of water consumption,and favorable economic and environmental benefits.

According to the characteristics of Ta and Nb hydrometallurgical process,cost accounting in Ta and Nb production process is discussed from the view of technical economy.Suggestions and methods are put forward,on cost management at all levels of the plant including department,workshop and team,and on the proper cost apportion between tantalum and niobium products.

Based on the optimized conditions for the chromogenic reaction between Mo（Ⅴ）and thiocyanate,the Mo content of molybdenum concentrate was determined by spectrophotometry with sulfocarbamide as the reducer.The as-tested Mo content in the Mo concentrate is less than 5%（n=6）,standardized recovery is in the range of 98.34%～100.30%.The said method is characterized by narrow confidence interval and high accuracy.

Al-Zr alloy with high zirconium content was digested through the household microwave oven and HCl-H2O2 system,and Zr content was titrated with EDTA.The conditions of microwave digestion were optimized through single factor experiments and orthogonal experiments.Compared with traditional methods,microwave digestion is characterized by fast digestion,simple operation,less sample loss and more accurate determination of Zr content.The Zr recovery is 97.11%～102.81%,and the relative standard deviation（n=5） 0.11%～0.13%.

The paper has summarized the latest development,advantages and disadvantages,of nano MoO3 preparation technologies,such as solid phase method,hydrothermal method,precipitation method,low-temperature liquid phase synthesis method,thermochemistry（phonochemistry） method,chemical vapor deposition method and so on.The development tendency of nano MoO3 in China is prospected.

The paper has summarized the preparation technologies for perovskite-type composite metal oxide,including citric acid method,chemical precipitation,sol-gel,hydrothermal synthesis,pyrolysis,solid state reaction.According to a series of characteristics of the oxide resulted from its cubic structure and oxygen vacancies,its application in the fields of gas-sensitive material,fuel cell,catalytic material,oxygen-permeable membrane are also described.

Based on the difference in property of isopolyacid or heteropolyacid between tungsten and molybdenum,the crystallization process of ammonium molybdate feed solution was operated by acid precipitation or evaporation under various experimental conditions.And the separation effect between tungsten and molybdenum in that process was investigated.The results show that the separation degree of tungsten from molybdenum is low in the acid-precipitation process,but obviously improved in the case of ammonium phosphate addition.The evaporation process is influenced by final pH value and ratio of tungsten to molybdenum in feed solution.Especially when the ratio is large,the difference in crystallization rate between tungsten and molybdenum is obvious,resulting in good separation effect.

The influences of extractant saponification value,solution acidity and Al concentration on the distribution ratio and separation factor of RE and Al in the chloronaphthenic acid system were studied.The results show that in the feed solution with high Al concentration,RE is separated effectively from Al by the above extraction system even under high solution acidity,where no emulsification occurs in the extraction process.And the optimal technological parameters of the extraction separation process are as follows：extractant saponification value 0.35 mol/L,Al concentration 12.5 mmol/L and pH=0.10.Under the above conditions,the distribution ratios of Al and RE are 0.53 and 0.05,respectively,and the separation factor of RE and Al is up to 10.6.

Aluminum-based composite photocatalyst was prepared by coating flake aluminum powders with TiO2 and using sol-gel method.The influences of technological parameters on the photocatalysis property were studied by orthogonal experiments.The samples were analyzed and characterized by XRD.The results show that the photocatalysis property is significantly affected by calcination temperature.The degradation rate of methylene blue is up to 93.5% through 3 h UV-lamp irradiation when hydrolysis temperature is 30 ℃,pH value 4.5,molar ratio of water to tetrabutyl titanate 50,and calcination temperature 600 ℃.