Rapidly-solidified Mg-Ni-RE Alloys and Their Nanocrystallization and Hydrogen Storage

QIN Chuan

Rare Metals and Cemented Carbides | Vol., Issue 1, 2004 | pp. 56-59

Study is made of hydrogen storage in rapidly-solidified Mg-based Mg-Ni-RE(RE=Y,Mm) alloys.The as-quenched alloys were amorphous or nano-/amorphous,consisting of nanocrystals(with average size of 3 nm) embedded in large amounts of amorphous phase.The hydrogenation properties (hydrogen storage capacity and hydrogenation kinectics) of Mg₇₆Ni₁₉Y_5 and Mg₁₈Ni₇₈Y_4 alloys were compared with those of Mg₇₅Ni₂₀Mm_5(Mm=Ce, La-rich mischmetal).

DOI: Cited: 0 Download: 0

Study of Southern RE Ore Leaching by Aluminum Inhibition

OU Yang-ke-xian;RAO Guo-hua;YAO Hui-qin;MAO Yan-hong

Rare Metals and Cemented Carbides | Vol., Issue 4, 2003 | pp. 1-3

In the course of southern RE ore leaching,Al is the major impurity affecting the product quality.Study is made of Al inhibition by addition of Al inhibitor in the ore leaching reagent to reduce leached Al.The optimization test results showed that Al in the resultant leachate is reduced by 56.85% by adding 0.05% HZA inhibitor in the leaching reagent and at controlled pH value 5.5 with little influence on RE recovery.

DOI: Cited: 0 Download: 0

Research on In Leaching Process

XIAO Hua-li

Rare Metals and Cemented Carbides | Vol., Issue 4, 2003 | pp. 4-6

Research is made on the leaching process of different In raw materials.The resultant 2-stage leach process is as follows:In the first stage,'low-acid'leaching is adopted for In enriched residue,high-grade In residue is leached first by concentrated acid followed by diluted acid while in the second stage,'medium-level acid'is used for leaching.The pilot-scale test results showed that the use of different leaching processes for different raw material can result in grade<0.25% in the secondary In leach residue.

DOI: Cited: 0 Download: 0

Research on Phase Ingredient of WO_3 During Reduction

FU Xiao-ming;WU Xiao-dong

Rare Metals and Cemented Carbides | Vol., Issue 4, 2003 | pp. 7-9

The paper describes the influence of phase ingredient on particle pattern of W-powder during reduction of WO_3(770～900 ℃).The research results showed that among β-tungsten oxide(WO_2.9)?γ-tungsten Oxide(WO_2.72)and WO_2,γ-tungsten oxide(WO_2.72)has the biggest influence on particle pattern of W-powder,WO_2 has the least influence on particle pattern of W-powder,while influence of β-tungsten Oxide(WO_2.9)is in the medium level of the three.

DOI: Cited: 0 Download: 0

Anti-dazzle Principle and Application of Nanometer-sized Compound Metal Oxide Films

LI Li-li;WANG Xiao-lan;DUAN Xue-chen

Rare Metals and Cemented Carbides | Vol., Issue 4, 2003 | pp. 10-11

In this paper is described the anti-dazzle principle of nanometer-sized compound metal oxide films.A multi-layered films has a structure in which a material having a low refractive index and a material having a high refractive index are alternately stacked to form films.Its anti-reflection effect is a synergistic effect produced by the optical interference function of each layer.

DOI: Cited: 0 Download: 0

Study of Synthesis and Properties of Tungstomolybdosilic Quartenary Complex O_2-containing and Cobalt-substituted Clusters

LI Wei;DAI Li-yi;DAN Yong-kui

Rare Metals and Cemented Carbides | Vol., Issue 4, 2003 | pp. 12-15

The paper describes the synthesis of tungstomolybdosilic quartenary complex O_2 -containing and cobalt-substituted clusters.The general molecular formula was determined:K_4H_2·21H_2O.By means of IR,UV,TG-DTA,the properties and structural characteristics of the said material was investigated.

DOI: Cited: 0 Download: 0

Ln_2O_3/MgO Catalyst for Synthesizng Plasticizer IOP

CHEN Qi-rui

Rare Metals and Cemented Carbides | Vol., Issue 4, 2003 | pp. 16-17

The catalytic esterification of rare earth oxides to synthesize plasticizer IOP was further improved by using the supported catalyst Ln_2O_3(MgO)(In=Nd,Sm,Er).The catalyst was prepared by coprecipitation-calcinations method,the increased catalytic activity was due to the high dispersion of rare earth ions on the surface of MgO.On the other hand,the amount of rare earth oxide used inh this method was reduced by about 80%,so the total production cost was much lowered.

DOI: Cited: 0 Download: 0

Study on Technology for Preparation of ITO Target by CIP and Sintering Process

LI Jing;CHEN Shi-zhu;LI Zhi-hua

Rare Metals and Cemented Carbides | Vol., Issue 4, 2003 | pp. 18-21

The paper describes the technology for the preparation of ITO sputter target by CIP and sintering process.ITO complex powder is produced by chemical precipitation followed by CIP under 200 MPa,at 60% of relative density of the compact,then 6-h sintering at 1 600 ℃ to produce ITO target at relative density >90%.In addition,the influence of powder size,sintering temperature and sintering period on the density of target are investigated.And the discussion is made on the sintering atmosphere and process.

DOI: Cited: 0 Download: 0

A Good-prospect Hydrometallurgical Process for Molybdenite

FU Jian-gang;ZHONG Hong

Rare Metals and Cemented Carbides | Vol., Issue 4, 2003 | pp. 22-26

The methods of molybdenum extraction from molybdenite were introduced.Comparison is focusing on the advantages and disadvantages of various hydrometallurgical processes.The results showed that electro-oxidation process was the most promising for molybdenite.Some suggestions on intensifying leach are put forward.

DOI: Cited: 0 Download: 0

Development of Technology and Equipment of Ta and Nb Hydrometallurgical Separation and Extraction

HAN Jian-she;ZHANG Jin

Rare Metals and Cemented Carbides | Vol., Issue 4, 2003 | pp. 27-31

The paper has introduced the resource structure and the developments of technology and equipment of HF acid-dissolution and pulp extraction in the course of Ta/Nb hydrometallurgy in China in recent years.Comparison is made on the techno-economic index in the main process.Some problems existing in the production are presented up and comments are made on the solutions.

DOI: Cited: 0 Download: 0