Simulated small-scale pilot heap leaching of low-grade copper sulfide ore with selective extraction of copper

The bioleaching of low-grade copper sulfide ore and the selective extraction of copper were investigated. Lix984 dissolved in kerosene was used as extractant. The results show that it is possible to selectively leach copper from the ores by heap leaching. The copper concentration of leaching liquor after 250 d is 2.17 g/L, and the copper concentration is 0.27 g/L after solvent extraction. The leach liquor was subjected to solvent extraction, scrubbing and selective stripping for the enrichment of copper and the removal of impurities. The pregnant copper sulfate solution produced from the stripping cycle is suitable for copper electro-winning.     

Hot deformation behavior of rare earth magnesium alloy without pre-homogenization treatment

The behavior and structure evolvement of as-cast Mg-Gd-Y-Nd-Zr magnesium alloy during the hot deformation process were discussed.The flow stress behavior of magnesium alloy over the strain rate range of 0.002-1 s~(-1) and the temperature range of 573-723 K was researched on Gleeble-1500D hot simulator under the maximum deformation degree of 60%.The experimental results show that the relationship between stress and strain is obviously affected by the strain rate and deformation temperature.The important s...     

Precision forging technologies for magnesium alloy bracket and wheel

Fundamental investigations on precision forging technology of magnesium alloys were studied.As-cast billet prestraining and a new concept of hollow billet were proposed in order to reduce the maximum forming load.A schcme of isothermal forming and the use of combined female dies were adopted,which can improve the die filling capacity and ensure the manufacture of high quality forgings.By means of the developed technique,AZ80 alloy wheel and AZ31 alloy bracket were produced successfully at suitable proces...     

TAMZ合金在人工唾液中的电化学行为

运用电化学方法对工业纯Ti，Ti6Al4V合金和TAMZ合金在人工唾液中的电化学行为进行了研究，探讨了溶液pH值对Ti合金电化学性能的影响。结果表明，在人工唾液中，TAMZ合金具有最佳电化学稳定性，腐蚀速率最低。Ti合金在人工唾液中存在较大的钝化区间，电化学稳定性按工业纯Ti，Ti6Al4V合金和TAMZ合金的顺序依次增强。随溶液pH值升高，试样的热力学稳定性增强。交流阻抗结果显示，3种实验材料在人工唾液中具有优异的耐蚀性能，腐蚀速率均在10^-2μm／a数量级，小于医用级标准0．25μm／a。     

不同形态硫化合物腐蚀行为的研究

综述了原油中活性硫及非活性硫的来源及分布情况,分析了其腐蚀机理,阐述了硫腐蚀的特点并讨论了温度、浓度、时间、循环条件、金属组成等影响腐蚀的外界环境因素,指出了金属硫腐蚀研究中存在的问题.     

STRUCTURES OF γ Al_2O_3 AND AlON STUDIED BY ~(27)Al NMR AND QUANTUM CHEMISTRY CALCTLATIONS

１．ＩｎｔｒｏｄｕｃｔｉｏｎＡｌｕｍｉｎｕｍｏｘｙｎｉｔｒｉｄｅ（ＡｌＯＮ）ｉｓｏｎｅｏｆｔｈｅｃｏｍｐｏｕｎｄｓｉｎｔｈｅＡｌＮＡｌ２Ｏ３ｓｙｓｔｅｍａｎｄｈａｓｍａｎｙｄｉｖｅｒｓｉｆｉｅｄａｐｐｌｉｃａｔｉｏｎｓ．Ｆｏｒｅｘａｍｐｌｅ,ＡｌＯＮｓｔｒｕｃｔｕｒｅａｌｌｏｗｓｆｏｒｐｒｏｄｕｃｔｉｏｎｏｆｏｐｔｉｃａｌｌｙｔｒａｎｓｐａｒｅｎｔｐｏｌｙｃｒｙｓｔａｌｌｉｎｅｍａｔｅｒｉａｌａｎｄｃａｎｅｌｉｍｉｎａｔｅｏｔｈｅｒｐｒｏｂｌｅｍｓａｓｓｏｃｉａｔｅｄｗｉｔｈａｎｉｓｏｔｒｏｐ…     

THE MICROSTRUCTURE AND PROPERTY OF IN SITU TiC_P/Fe COMPOSITE

１．ＩｎｔｒｏｄｕｃｔｉｏｎＴｉＣｐａｒｔｉｃｌｅｓｒｅｉｎｆｏｒｃｅｄｆｅｒｒｏｕｓｍａｔｒｉｘ（ＴｉＣＰ／Ｆｅ）ｃｏｍｐｏｓｉｔｅｓｈａｖｅｐｏｔｅｎｔｉａｌａｐｐｌｉｃａｔｉｏｎｓｉｎａｎｕｍｂｅｒｏｆｉｎｄｕｓｔｒｉｅｓｄｕｅｔｏｔｈｅｉｒｌｏｗｃｏｓｔａｎｄｓｕｐｅｒｉｏｒｗｅａｒｒｅｓｉｓｔａｎｃｅ．Ａｔｐｒｅｓｅｎｔ,ｐｏｗｄｅｒｍｅｔａｌｌｕｒｇｙｒｏｕｔｅｓｈａｖｅｂｅｅｎｅｍｐｌｏｙｅｄｏｎａｎｉｎｄｕｓｔｒｉａｌｓｃａｌｅｔｏｐｒｏｄｕｃｅｓｕｃｈｃｏｍｐｏｓｉｔｅｓｕｎ…     

Welding mode transition and process stability in high power laser welding

For high-power CO_2 laser welding, besides two well known stable welding processes, i.e. stable deep penetration welding (DPW) and stable heat conduction welding (HCW), the authors have found the third welding process, i.e. unstable-mode welding (UMW) under the certain condition. UMW has its basic feature that the two welding modes (DPW and HCW) appear intermittently, with jumping of penetration depth and weld width between large and small levels. In this paper, effects of welding parameters (focal position, laser power and traveling speed) on laser welding mode and weld appearance have been comprehensively studied Double-U curves of laser welding mode transition have been obtained, which indicate the ranges of the three mentioned welding processes. This work affords science foundation for selecting the welding process parameters correctly and obtaining stable laser welding.     

Zr基块体非晶合金在过冷液态区微正挤压实验研究

为了研究Zr55Cu30Al10Ni5大块非晶合金在过冷液态区内的微正挤压变形行为,采用不同尺寸非晶合金圆柱形棒料在不同长度凹模工作带下进行了微正挤压实验。实验结果表明：所选非晶合金在成形温度450℃、初始应变速率0.001～0.01s-1的条件下正挤压是可行的;随着坯料尺寸减小,其单位挤压力和挤出胀大比均增大,且挤压成形力表现出不同的变化趋势;坯料在短凹模中的单位挤压力和挤出胀大比分别大于在长凹模中的单位挤压力和挤出胀大比。     

电插式液体清香剂挥发芯的选择研究

主要研究了不同材质、不同受热长度、不同直径大小的挥发芯对电插式液体清香剂剂液挥发量的影响。