In consideration of the fact that mechanical activation affects the surface fractal property of solid, the leaching kinetic equation was rededuced in the light of fractal geometry. This equation shows clearly the increase of surface fractal demention will accelarate the leaching. This effect was distinguished from that of the increase of k value due to mechanical activation and decrease of γ0 due to milling.

Investigation is made on the low-concentration, low-addition HCl digestion of scheelite concentrate. The results show that the average digestion rate can reach 97. 35% in 1. 5 hour at 95～10℃ with the addition of HCl (10% concentration ) .1. 5 times more than the theoretical value. Compared with the traditional acid digestion process, the said process can bring about large reduction of HCl consumption and concentration, resulting in large reduction of waste acid treatment cost and elimination of HCl gas volatization during acid digestion. In this way, the working conditions are improved and the cost for the control of HCl gas pollutant for environmental protection is also reduced. However, the said technology doesn't remove Mo and needs larger acid liquid volume (1. 5 times as much as that of the traditional technology).

Study is made of the effects of roasting temperature, roasting time, fluoration and different intermediates on the properties of RE polishes from RE chloride. The properties of obtained RE polishes are indicated by particle analyzer, SEM,XRD. The results show that the following process is more for RE polishes (NH4)2SO4 precipitation followed by NaOH conversion,fluorating and 3 h roasting of the intermediate at 900 ℃

In this paper, the effects of forge deformation on the microstructres and properties of steel-bonded cemented carbides have been studied. The results show that the use of die forging is suitable for processing the steel-bonded cemented carbides. The use of die forging can not only refine the structure, but also make up for the defects in the process of free forge. It improves forge efficiency and proportion of finished products.

This paper describes a study on the commercial possibility of compounding a steel-based as-cast ceramal. Factors of the compounding process has been analysed. This paper indicates that a key for producing the steel-based as-cast ceramal is to assure better liquidity of a melted steel entering prefabricated layer of the ceramal.The use of additives for this can give better result.Keyworks:steel-based; as-cast ceramal compounding process

The feasibility of using butadiene styrene rubber and butadiene rubber as forming agent of cemented carbide has been studied. The experiments have shown that this two kinds of synthetic rubber can take the place of butyl sodium rubber and can be used as forming agent for the production of cemented carbide.

In this paper, the Tio. 56Ni0. 37La0. 02Zr0. 05 and Tio. 53Ni0. 38La0. 09 alloy film was made by magnetron sputter. The results show that the maximum electro-chemical capacity of the former is 243mAh/g, about 30% higher than the latter.

Study is made on the influence of RE content in RE A356 alloy on the physical /chemical properties of A356 alloy cathode-electrophoretic coating film. The resutts show that addition of some rare earth can result in fine alloy structure, higher surface finish, easy phosphating. And the resultant phosphating film features good density, flexibility and electrophoretic coating ability. Optimum content of RE is 0. 05%.

The processability of low-Re Mo alloy manufactured by PM is studied. It was observed that the tensile strength and initial recrystallization temperature of the said alloy were increased wiht the incresae of Re content. The relation between tensile strength and annealing temperature conformed to linear regressing equations for the wire specimens with 1%,3%,and 5% Re at 900 to 1400℃ annealing temperatures.

Brief description and analysis are made with respect to the quality defects (ie cracks, split and corewrapping) during W-Ce ingot processing. Preliminary investigation is made into the ways to prevent the defects and to improve the product quality.