Study is made of the variation mechanism of Nb 2O 5,main physical properties,ie grain shape,crystalline structure,average particle size,specific surface area and bulk density under calcination temperature.The law of the variation with the temperature variation is found out.Investigation is made on the reasons for the variation.Analysis is made of the relationship between Nb 2O 5 average particle size,specific surface area and bulk density so that the average particle size and specific surface area can be quickly calculated out by measuring the bulk density.

Description is made of the heat-shrinkable compounds and materials,which have arisen interests in the field of science and technology in the last 5 years.These materials are classified in three structural models:SC 2(WO 4) 3,AM 2O 7and cubic ZrW 2O 8 polymorphs.The cubic ZrW 2O 8 was introduced emphatically because it is an isotopic heat-shrinkable compound with as wide as one thousand temperature range.The improvement on cubic ZrW 2O 8 was discussed,too.

Study is made of the process for the production of zirconium sulfate from zircon.The main Steps are as follows:alkali fusion,water washing and conversion,primary and secondary crystallization;centrifugal packing.This unique process has solved the problems in Zr and Na separation,Zr and Fe separation and crystal morphology etc.The product quality can meet the requirements of the customers both at home and abroad.

This paper reviewed the development of the synthesis techniques of nanocrystalline WC-Co composite powders,summarized the sintering characteristics of nanocrystalline WC-Co cemented carbide.The present reaesach status is analyzed,the problems and research tendency are also discussed in the paper.

The development of lithium ion battery anode materials was described.The properties and preparation methods of lithium cobalt oxide and lithium nickel oxide were introduced in detail.

General descrption is made of the domestic RE products and comparison is made with the international standard.Description is also made of the present status and development and problems both at home and abroad in respect of RE permanent-magnet material,RE automobile off-gas purification catalyst,RE fluorescent powder,RE W electrode,etc.Analysis is also made of the development of RE new material.

Description is made of extraction of U and Th contained in the process effluent with reference to U and Th source,dissolution mechanism and U and Th content in the effluent as well as nature of process effluent from Nb/Ta manufacturers.After treatment,the process effluent can be discharged up to the state discharge standard.

The structures of portable horizontal rubber removal furnaces are described.Contrast experiments are made between the two for the comparision of their effect.The result shows portable horizontal disintegrated furnaces have the advantage of energy saving resources?even tempeature and long service life,as can meet the requirements for quality JY·1 cemented carbide production.

The paper has summarized the development of medium and small-size hard alloy enterprises in the recent years and analyzed some typical'developing'medium and small size enterprises.Results show that the medium and small-size hard alloy enterprises still have space for further development.In order to realize stable existance and development,they shouldconcentrate theit energy on relatively narrow vocational depatrment.On the other hand,it should adhere and raise the particularity on the chain in the trade division of labor and judge the rationality from the point of economic benefits so that they can be adapted themselves to market competition.

Organization and the latest dovelopment of Sandvik Group in Sweden are introduced.