Web Of Tech

Study of Purity Improvement of Rare Earth Oxide in South Ore Deposit

HE Lun-yan;WANG Shi-nan;ZHOU Xin-mu;JIAO Xiao-yan;WEN Zhi-yu

Rare Metals and Cemented Carbides | Vol., Issue 3, 1995 | pp. 1-5

The technology for purity improvement of composite RE oxides in south ore deposits is studied. Raw material is leached by a selected strong-acid ammonium salt at a control led PH and with addition of ammonium sulfide as purification reagent. Leached solution is pretreatmented with reagent at a proper PH. Pretreatmented solution is subjected to double precipitation first with ammonium bicarbonate and then with oxalic acid to obtain pure RE. Precipitating ratio, PH and amount of ammonium sulfate are important factors to RE purity. Aforesaid method is useful to various solutions.

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The Effects of Trace Rare Earth Element La,Ce on the Damping Capacity of the Zn-Al Alloy

ZHOU Shan-chu;LUO Bing-hui

Rare Metals and Cemented Carbides | Vol., Issue 3, 1995 | pp. 6-10

The effects of the trace La and Ce on the internal frictionand damping stability of the Zn-Al alloy has been studied in this paper.The experimental results show that adding trace rare earth element La/Ce can improve the damping capacity and damping stability of Zn-22wt%Al alloy.

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Development of WC Hardening Materials for Undermine Drilling Tools

ZOU Xu-mei

Rare Metals and Cemented Carbides | Vol., Issue 3, 1995 | pp. 11-19

The paper has summerized the development of WC Hardening material for undermine drilling tools since 1970s with reference to some literatures both at home and abroad and on the basis of some tests made by the writer. Detailed analysis is made of the reasons why fissures,peeling-off, and tooth breaking exist in the build-up welding layer of cast WC for hardening material of steel-toothed gear drills. The effectiiveness of new hardening materials such as YM alloy, sintered WC, veneered hard alloy and nodular hard alloy is well demonstrated from various test datum.

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Cutting Test of Cemented Carbides Prepared by Using a New Carbusintering Technique

ZHANG Qi-xun

Rare Metals and Cemented Carbides | Vol., Issue 3, 1995 | pp. 19-22

This paper describes the cutting test of hard alloy tip produced by using the new carbusintering technique. This type of tips has presented a good wear resistance equal to that of typical cemented carbides YG6 tips when cutting austenitic stainless steel, nodular cast iron and chilled cast iron.

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A Study on Mo-Co Alloy Wire

CHENG Jun;LIU Xin-yu;ZHANG Hou-an

Rare Metals and Cemented Carbides | Vol., Issue 3, 1995 | pp. 22-25

The effects of cobalt on the reduction of molybdenum powder and mechanical properties of annealed Mo wire were investigated. The results show that the adding of cobalt benefits the reduction of MoO3and increases the density of sintered molybdenum bar. It also shows that cobalt can decrease the recrystallization temperature of molybdenum wireand distinctly improve the ductility of annealed molybdenum wire.

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Preparation of Refractory Metal Compounds by Mechanical Alloying

ZHANG Qiao-xin;WANG Sheng-rui;MAO Tian-er

Rare Metals and Cemented Carbides | Vol., Issue 3, 1995 | pp. 26-28

The characteristic of mechanical alloying (MA) is described in this paper: emphasis is given to the study of the process and mechanism of refractory compounds made by MA. We consider that it is an effective method to make the refractory compounds by MA.

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Study of the Application of W Electrode in Molten-salt Electrolysis of Nd

LIU Hui

Rare Metals and Cemented Carbides | Vol., Issue 3, 1995 | pp. 29-31

W electrode is used instead of the imperfect Mo electrode in the molten-salt electrolysis of Nd. The fabrication steps and connection method of W electrode is investigated.

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Effect of Organic Acid as Buffer Media on the Colour of RE-Arsenazo-Ⅲ

LI Yong-xiu;HE Xiao-bin;HU Ping-gui;GU Zi-ying

Rare Metals and Cemented Carbides | Vol., Issue 3, 1995 | pp. 31-34

Effect of three organic acid solutions(formic acid acetic acid and chloroacetic acid) on the colouring property of RE-Arsenazo-Ⅲ isinvestigated comparatively. Results show that formic acid is the bestselection as the buffer media for the determination of RE by arsenazoⅢ colouring.

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Application of Phosphonazo Developer in the Analysis of Metals and Alloys

DUAN Qun-zhang

Rare Metals and Cemented Carbides | Vol., Issue 3, 1995 | pp. 34-41

The latest development of application of phosphonazo developer in the analysis of metals and alloys is described. Colouring reaction conditions. something about the inspection limit. interference and measuring scope of the related spectrophotometry are presented in the paper.

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