The finite element analysis software ANSYS is applied for the simulation study of the process of filling complicated cavity. The results are similar with those Crocher got by the commercial software Polymold, indicating that both the model and calculation method are feasible. And prediction is made of conditions of the occurrence of some common defects. Discussion is made on how to select the injection process parameters based on the simulation results by the analysis of the distribution of fluid front, temperature and pressure fields. The prospect of future application is presented.

The WC-6Co cemented carbides were rapidly prepared by the in-situ synthesis during sintering by applying the SPS technology, using WO3,Co3O4 and carbon mixed powders as the raw powder material.The effects of the sintering temperature and the pressure on the degree of compactness, the grain microstructure and the mechanical properties of the alloy were studied. The pure phases of WC and Co were obtained when the sintering temperature of 1 270℃and the pressure of 90 MPa were used. The prepared samples have the relative density as 99%,the hardness HRA≥93 and HV≥1 900.

Nanocrystalline WO3 powder is prepared by mechanical ball milling. Study is made on the influences of ratio of ball to powder, ratio of solid to liquid,and grinding time on powder characteristics were studied, The influences of ratio of ball to powder and grinding time was very serious. Longer grinding time and bigger ratio of ball to powder would not result in finer powder,but increase of the WC impurity content. Too higher or too lower ratio of solid to liquid is not good for further fineness of WO3. In order to gain higher purity nano WO3 powder ,the best condition of WO3 preparation would be as follows：ratio of ball to powder 1：1,ratio of solid to liquid 1：0. 5,grinding duration 48 h.

Study is made of mechanical property and the microstructure of alloy with some analysis of relevant laws of change in order to find out effective approach for the preparation of high-density W-Ni-Fe alloy.

According to the＂Empirical Electron Theory in Solid and Molecule（EET）＂,with the＂hard sphere model＂,the valence electronic structures of the GP zone in Cu-Cr alloys are calculated. The results show that Cu atoms are able to form covalent with Cr atoms, forming the GPzone-zone of Cr atom partial poly-merization,while the strongest and stronger covalent bonds in GP zones are stronger than the strongest bonds in α-solid solution cell, as can improve the strength of covalent bonds hardness and obviously increase alloy strength.

The new concept of production factor and concentration factor is introduced to derive series of formulas for determination of carbon and oxygen mix and carbon ratio in furnace charge based on the mixing of the material so that the functional relationship between the formulas and target carbon and oxygen content. The concept of mixed oxide is introduced to solve the problem of mutual restriction between components in the mixing of multi-element carbides. The calculations of multi-element carbide and single-element carbide are combined,resulting in accurate and reliable calculation process.

Description is made of the formation and distribution of the ＂three wastes＂ in Ta ＆ Nb hydrometallurgical operations in China, focusing on the general situation of the existing ＂three wastes＂ disposal technology/equipment/and products recovered. Study is made of the existing problems and with some proposals presented for comprehensive recovery.

Description is made of the present status of alkali autoclave process for tungsten metallurgy. The application of two-stage autoclave process can improve the W metal recovery up to 〉97% and decrease WO3 in the mixed residue down to- 1%.

Study is made of the direct determination of Fe content in the Dy-Fe alloy by ICP-AES. The test results showed that the use of the standard working curve can avoid the effect from the matrix. The detection limit is 0. 04%,and recovery varies from 96.2%to 102.4%.

In the paper is summarized the Nb/Ta solvent extraction mechanism. Description is made of the common spectrophotometric developer and its applicable system;the determination conditions,various tesring indices, common interfering ions and shelters, resultant complex composition and stability, etc. The future development tendency of the developer is also looked forward,