The Paper outlines the application and development ofhigh-temperature sessile drop method and equipment for the determinationof surface tension and wetting angle.

In this paper, international market and recent developmentsin extractive metallurgy of scandium are reviewed. The strategy policyfor development of the scandium industry in China have been presented.The authors suggested that we must try to improve the scandium extractivetechnology, especially for high purity scandium and to decrease their production cost.At the same time,we must also pay more attention to the masteringof the work on Al-Sc master alloy and to application of Al-base alloys.

The paper introduces the distribution of mineral resources of vanadium in the world and its main manufacturers. It in detaildescribes the present status of V Applications in the fields of ironand steel industry. nonferrous metal industry, chemical industry,alloyssuperconducting material, automobile industry and other industry. Itforecasts the demand and supply of vanadium.

This paper presents the results of a comprehensive investiga tion into the drilling and grinding of ceramics from the view-pointsof reducing machining force and obtaining high-quality components.

Using the thin layer static method, the oxiding kinetics of W powder have been studied. The powder for study is classified by fluidized new technique. Results show that oxidization of W particles also follows the parabola-straight line oxidization mechanisin. On the basis of the exper imental results the mathematical model of oxidization for W powder has been established.

Technological conditions for concentr ation of rare earths from Nacl-type leachate with emulsive liquid membrane have been studied. These conditions include the oil-inner ratio(R,), the keroseneliquid paraffin ratio in the membrane phase, the surfactant quantity,the inner phase acidity, the rare earth concentration in the leachate,the aqua-emulsion ratio(Rwe), the use of P507 or P204, the stirring time ane so on. Through experiments the suitable formulation for the concentration of rare earths with emulsion liquid membrane(N205-P50(-keroseneliquid paraffin-HC1) and some better operation conditions are obtained.The concentration of emulsion liquid membrane concentrated rare earths can reach 100g/L and the rare earth extraction efficiency can reach 96%.

The influence of technical conditions on dephosphorization & deferrization during prereduction in the 'Two step' metallurgy of Nb and Fe has been studied. Optimized technical conditions for Nb/Fe>1. 0 Nb/P>10 Nb-rich slags are obtained. Analysis is made on the Nb-rich slags nad semi-steel structures of by-products.

During the fractography of W-Ni-Cu alloy, various defects such as pore, pollution and ingredient segregation and so on. have been found. This paper analyzes the technological factors causing formation of these defects and gives suggestions for process improvement.

The paper gives a summary of the development of annularspace centrifugal extractors both at home and abroad. The focus is the research and commercial-scale test of the big-diameter annular-space centrifugal extractors with illustration of the design and calculations.The design has obtaind patent in China.

A new pulping and scrubbing unit for removal of fluorine ion impurity from Nb2O5 is recommended and described. By comparision with traditional open unit, tins equipment has the advantages of lower energy consumption, faster pulping and scrubbing, lower labour omtemsoty and much less repairing work. It can also be used for scrubbing operation in hydrometallurgy.