After the analysis of rare earths market both at home andabroad, the author has given six suggestions for fully application ofHunan's rare earths advantages to develop new rare earth products.

Study is made of the influence of various tech n ical factors on the characteris ties of crys talline W powder so as to produce the said new produc t for special purpose. Successful technology is found for the said product through special measures such as reduction with additiyes to increase the particle size: ball milling for better powder fluidity; solvent scrubbing for the decrease of oxygen content.

The technology of the K2TaF7 sodium reduction for Ta powder production at home and abroad has been summarized. And its prospect is given.

Technical process and application of indium are described ,and its future is also predicted.

Oeyeloplnent of the laser technique and application of rareearth elements in the laser materials are briefly described. Suggestions are put u 3 for the development of Hunan's rare-earth laser materials.

This paper reviews fluorides CVD methods for refractory metals in CIS countries, including modern development of the equipment and products.

In this paper the self-propagating high-temperature synthesis process have been investigated, and advantages and characteristics of the SHS process have been described.

The crystalline rare earth (La、Ce、Pr、Nd) carbonates were precipitated using ammonium bicarbonate as precipitant. Chemical analysis of the composition of these compounds has been carried out. X-ray powder diffractomtry, IR spectrum and TGA、DTA of these compounds have been studied. The compositions of the rare earth carbonates have been determined to be RE2(CO3)3 ·xH2O(RE=La2、Ce、Pr、Nd, x=2、3 、4 ).

Ammonium tungstate is made from scheelite by acid dissolution. Then ammonium tungstate is obsorbed by activated carbon at pH 1 .8 and absolved at strong base. Tungstic acid is precipitated at pH1.Tungstic acid is then dissolved in hot ethandiol and it is reprecipitated under HC1 condition. The purified precipitate burns at elevated temperature and high pure tungsten trioxide can be obtained. Tungsten trioxide is 99. 9% (by scanning electron microscopy, ICP, photometric analysis).This method has the advantages of simple operation, easy post treatment and improved efficiency over the ion exchange or solvent extraction method.

The raw materials of various tungsten oxides strongly affect the particle size of tungsten powder. Therefore, it is highly important to make the right production and choice of the tungsten raw material in the production of tungsten powder. The fine tungsten powder has been effectively obtained by hydrogen reduction of purple tungsten oxide.