Spectrum grade ferroniobium base can be produced from selected raw materials and proper aluminium with additives at a suitable temperature.Impurity content in the base is below GB 7737-87 standard for ferroniobium.

Basing on the publications and the information from 13th Plansee Seminar, a survey on global modern R and D in refractory metals (RM) and hard materials(HM) was presented. The general introduction in bilef of the Seminar was submitted at first. and then, the recent developments in RM.HM and coating techniques were reviewed. Some problems were discussed.

This paper is a review of the scattered metals(such as Ga In.T1.Ge.Se.Te and Re),including their geology. reserch. process technology. uses.market,environment and outlook both at home and abroad in recent years.It indicates that the scattered metals have played an important part in the Gulf War and have a great significance in state security.

The importance of complex utilization of tungsten resources is described.The technology and processes for complex utilization of tungsten resources abroad are introduced and evaluated.

The paper briefly describes the technology for step hot rolling of BT1-0,OT4 and BT3-1 titanium alloys on 120 and 600 rolling mills and analyzes the structure and properties of obtainable billets

This article describes the close relations between alumillium-lithum alloys and modern-aviation and spaceflight,and discusses the development and' prospect for production and application of the new alloys.

Additive aluminium oxide can inhibit impurities during alkaline leaching of tungsten-bearing raw materials. The inhibiting effects of products obtained during calcining aluminium hydroxide at different temperature as additives are studied. Structure and characters of different aluminium oxide are inverstigated by X-ray diffraction, electron microscope, thermal gravity analysis, size analysis. The Suppression of arsenic and silicon with aluminium oxide is discussed.

Some experiments were carried out to demonstrate the mass transfer model of extraction of rare earth by emulsion liquid membrane. It was shown the present model proposed in Part(Ⅰ) was not only in good agreement with the experiments, but also mathematically simple.

Studies of extraction equilibrium of erbium by di(2-ethylhexyl) phosphoric acid (D2EHPA)in sulphonated kerosene were made.The equation, for the extraction equilibrium and the [equilibrium constant were obtained.The extraction and stripping rates were measured using a constant interfacial area cell. The effects of the concentrations of Er3+ , H+. D2EHPA and the complex on the reaction rates were investigated and the rate expression of this reaction was obtained. The interfacial reaction model was proposed, which was identified by kinetic study and the measurement of interfacial tension

This paper is an investigation on NH4HCO3 precipitation methods-for crystalline rare earth carbonates from rare earth salts aqueous solution of ammonia.Traditionally, the obtainable precipitates are voluminous floccule. But the application of ageing seeds.saturation and saturation-seeds during precipitation can obtain filterable crystalline precipitates.