Based on layout and special requirements for balanced water pressure of the rare metal pyro-metallurgical plants,the design measures and treatment method of recycled water supply system are given so as to ensure safe handling of the water equipment and save water resource.

General description is made of WTO and significance of China's entrance to WTO.Based on the analysis of present status of China's cemented carbide industry,the paper has described the challenges and opportunities existing in China's carbide product upgrading industry.Related suggestions are put forward.

Based on the investigations on the websites construction in the related P/M research units and large/medium enterprises,analysis is made of the new management features of the enterprises in the era of internet economics.The paper pointed out the importance of effective utilization of internet information for scientific research ,technical exchange and production development

The effect of some anions,such as SO 2- 4,CI - and OH -,on the W exchange capacity is studied in this paper.The experiment results show that with the increasing of these anions,the W exchange capacity decreases.Meanwhile,with the existence of these three kinds of anions,the orthogonal experiment results show that the order of the degree effect on W exchange capacity is CI ->SO 2- 4>OH -,and that in the solution before exchange,[WO 3]=20g/l,[SO 2- 4]<0.03125mol/L,[CI -]<0.00846mol/L and [OH -]<0.4706 mol/L is feasible.With the existence of these anions,the W exchange capacity can be increased through series columns.

Based on pH situ determination data,together with the results of variation in precipitation volume and precipitation partical size,the properties of lanthanum carbonate precipitated with sodium bicarbonate were investigated.The results show that crystalliazation active zone of lanthanum carbonate is in low molar ratio zone,where the moalr ratio is between 0.541～2.828.However,the crystallization of lanthanum carbonate in high molar ratio zone is inactive.At the same tine,the influence of stirring on the crystallization of lanthanum carbonate was examined ,the crystallization mechanism was discussed and the corresponding reaction equations were proposed.

The bulk density of Nb 2O 5 can be improved from 0.4～0.5g/c.c to 1.1g/c.c,and the content of Nb 2O 5 to 98%,LOI be reduced down to less 1% by changing the precipitating condition,controlling of washing time and adjusting of calcination temperature,addition of a proper quantity of additive if necessary,for precipitation of Nb solution with ammonium.

Study is made of production of high purity Dy metals by magnesium reduction.The results showed that high purity (up to 99.99%)Dy can be obtained by the following process:preparation of unhydrous DyCl 3 by chloridization of high purity(4N)Dy 2O 3 with high purity chloridizing agent;then magnesium reduction of unhydrous DyCl 3 to obtain Mg Dy alloy followed by distillation to obtain Dy metal.

The mixture of Mo and Si powders was milled by mechanical ball milling.The effect of ball milling technology on mechanical alloying of MoSi 2 was systematically investigated.The results showed that MoSi 2(t) Was more easily formed by hard alloy ball milling than stainless steel ball when the ball to powder mass ratio was 5∶1,10∶1 and 30∶1.The time of the formation of MoSi 2 Was the same with two different ball milling medium when the ball to powder mass ratiowas 20∶1

PIM(powder injection molding) is an advanced forming technology and is drawing more and more attention.Powder injection molding of cemented carbides is a complicated process due to the materials'characteristics.There are still several big problems to be solved to improve the technology.In this Paper,defect control,carbon control,dimension precision control and its mechanical property improvement are discussed and some measures are proposed to solve the problems.

The applied techniquies on forging,heat treatment and machining of GT 35 steel bonded carbide ingots are studied in this paper,the process parameters are provided.The rsults are important reference data for the further development and application of the said material.