Degradation of Lix984N and its effect on interfacial emulsion

1 INTRODUCTION Interfacial cruds are supposed to be one of the commonest and most troublesome problems emerging out in practice of copper solvent extraction. Generally, interfacial cruds are inhomogeneous oil/water emulsions that consist of organic phase, aqueous phase and solid particles. It can lead to a lot of detrimental effects on plant operations including difficult phase disengagement, contaminated electrolytes, extractant loss, declined product quality and polluted environment. Lo…     

Mechanism of crud formation in copper solvent extraction

The authors investigated the mechanism of crud formation in copper solvent extraction. It is indicated that pH value of solution and the phase ratio (O/A) are the main factors affecting crud formation in solvent extraction. The amount of crud extraction increases with aqueous pH value increase, and reduces with the increase of the phase ratio. Fe3 , Mg2 , fine air bubble and suspended particulates in leaching solution contribute to crud formation. One case is that a series of reactions of hydrolization and polymerization occurs for Fe3 , while pH＞2.5, polyhydric complex or Fe-SO4 complex are formed. Then the complex-ions of FeOH2 , Fe2(OH)4 2 cause poly-reaction, which is likely to lead emulsion. The study on Zeta potential indicates the repulsion between electriferous droplets in solvent extraction prevents phase coalescence, which is one of the major reasons for emulsion.     

氧化亚铁硫杆菌生长过程中铁的行为

研究了氧化亚铁硫杆菌在９Ｋ培养基中生长及铁的行为。以Ｆｅ２＋的氧化表征氧化亚铁硫杆菌的生长特性及活性，表明生长繁殖过程经历诱导期、缓慢期、指数期、稳定期和衰亡期。氧化亚铁硫杆菌在生长过程中，不断地将Ｆｅ２＋氧化为Ｆｅ３＋，同时Ｆｅ３＋又发生一系列的水解反应，并生成黄铵铁矾沉淀。Ｆｅ２＋的细菌氧化主要以Ｏ２为最终的电子受体。     

氧化亚铁硫杆菌亚铁氧化活性诱变育种理论探讨

结合已有的实验研究探讨了氧化亚铁硫杆菌亚铁氧化活性诱变育种过程中出现的几个理论问题 :突变基因性质 ;正突变与细菌修复系统 ;诱变剂选择与“钝化”防止 ;遗传稳定性与抑制基因突变 ;有效的育种程序。以期在进一步诱变育种中加快进程 ,获得遗传稳定、氧化快的突变株     

Biosorption mechanism of Cr (Ⅵ) onto cells of Synechococcus sp.

The biosorption mechanism of Cr (Ⅵ) ions on Synechococcus sp. biosorbent was studied by analyzing the biosorption kinetics as well as speciation change and bond formation during the biosorption process. The kinetics study shows that the adsorption process of Cr (Ⅵ) consists of a very fast stage in the first several minutes, in which more than half of the saturation adsorption is attained, and a slower stage that approximately follows the first order kinetic model, basically Freundlich isotherm models were observed. Comparative studies of FT-IR spectra of K_2Cr_2O_7, free cells of Synechococcus sp., and Cr-bound cells of Synechococcus sp. show that the speciation of chromium that binds to the cells of Synechococcus sp. is Cr (Ⅲ), instead of Cr (Ⅵ), and the carboxylic, alcoholic, amido and amino groups may be involved in the binding of Cr (Ⅲ). Integrative analyses of the surface electric potential, the effect of pH value on adsorption behavior of Cr (Ⅵ), and the results of FT-IR show that the biosorption of Cr (Ⅵ) follows two subsequent steps, biosorption of Cr_2O_(7~)2-))by electrostatical force at the protonated active sites and reduction of Cr_2O_(7~(2-)) to Cr3+ by the reductive groups on the surface of the biosorbents.     

黄磷电炉配碳团块的热性能

用有机粘结剂成型黄磷电炉原料制备成配碳团块，研究了其热抗压强度、热膨胀性、软熔性能及还原性能．结果表明，配碳团块的热性能能保证电炉冶炼的顺利进行．在１８００ｋＷ黄磷电炉上配加６０％配碳团块进行工业实验，改善了黄磷电炉的冶炼状况，每吨黄磷降低电耗约１１％．     

Kinetics of electrochemical process of galena electrode in diethyldithiocarbamate solution

1　ＩＮＴＲＯＤＵＣＴＩＯＮＤｉｅｔｈｙｌｄｉｔｈｉｏｃａｒｂａｍａｔｅ (ＤＤＴＣ)ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｆｒｅｑｕｅｎｔｌｙｕｓｅｄｃｏｌｌｅｃｔｏｒｓｆｏｒｆｌｏｔａｔｉｏｎｏｆｈｅａｖｙ ｍｅｔａｌｓｕｌｆｉｄｅｍｉｎｅｒａｌｓ ,ｓｕｃｈａｓｇａｌｅｎａ ,ｃｈａｌｃｏｐｙｒｉｔｅａｎｄｊａｍｅｓｏｎｉｔｅ ,ａｎｄｉｔｓｈｏｗｓｓｔｒｏｎｇｓｅｌｅｃｔｉｖｉｔｙ[1] .ＷｈｅｎＤＤＴＣｗａｓｕｓｅｄｉｎｈｉｇｈｌｙａｌｋａｌｉｎｅ (ｐＨ >11.4 )ｆｏｒｓｅｐａｒａｔｉｎｇｇａｌｅｎａｆｒｏｍｓ…     

黄铜矿与斑铜矿在酸性细菌培养基中的电化学溶解对比(英文)

采用电化学测试和X射线光电子能谱(XPS)测试分析黄铜矿与斑铜矿在酸性细菌培养基中的电化学溶解过程。斑铜矿直接氧化反应比还原反应更容易发生,但黄铜矿既难被氧化,又难被还原。斑铜矿具有更高的氧化速率,从而比黄铜矿更容易被溶解。铜蓝(CuS)是黄铜矿与斑铜矿溶解过程的中间产物。因此,斑铜矿的溶解途径主要为直接氧化过程,中间产物铜蓝(CuS)可能限制其进一步溶解。黄铜矿的溶解途径包含了还原-氧化过程,其中,黄铜矿首先被还原为与斑铜矿类似的中间产物,再进一步被氧化,并产生铜蓝(CuS),而黄铜矿的最初还原过程是其溶解过程的主要限制步骤。     

苯乙烯膦酸体系中细粒金红石的疏水絮团浮选（英文）

通过浮选试验、动电位测试、显微镜观测、激光粒度分析、吸附量测定和DLVO理论研究细粒金红石在苯乙烯膦酸(SPA)体系中的絮团浮选行为。单矿物浮选试验结果表明,苯乙烯膦酸对细粒金红石的絮团浮选具有良好的诱导作用;同时,溶液pH值、剪切力(搅拌速率)和搅拌时间均对絮团浮选效果有一定影响。动电位测试发现,随着SPA的加入,等电点及电位均负向移动,表明矿物与药剂之间主要发生化学吸附。激光粒度分析表明,在搅拌速度为1800 r/min和1000 mg/L SPA时,金红石颗粒的尺寸最大。此外,通过显微镜观测和浮选试验证明絮团的产生有利于细粒金红石的浮选。综上可得,SPA通过化学吸附作用能有效诱导细粒金红石的疏水絮团并增大其颗粒尺寸。最后,通过DLVO理论计算进一步验证SPA与金红石颗粒之间主要发生化学吸附作用,进而促进絮团产物的形成。     

混合中度嗜热微生物浸出两种不同类型低品位铜尾矿的比较研究（英文）

利用混合中度嗜热微生物浸出比较研究两种不同类型的低品位铜尾矿(酸浸尾矿和铜浮选尾矿)在浸出过程中矿物学和微生物学特征的变化。结果表明:两种尾矿的浸出行为具有很大的区别。与铜浮选尾矿相比,酸浸尾矿的浸出液中氧化还原电位较低,[Fe3+]/[Fe2+]的比例和微生物菌体密度较高,导致总铜、原生硫化铜和次生硫化铜的浸出率增加。XRD结果表明,在浸出浮选尾矿中,检测到石膏和金属有机复合物,这些物质会减缓硫化矿物的氧化过程。两种尾矿浸出过程的微生物群落变化明显:酸浸尾矿浸入过程中铁氧化菌的比例高于浮选尾矿浸出的,但硫氧化菌比例低于浮选尾矿浸出的,浸出酸浸尾矿时可以检测到F. thermophilum L1,但在浸出浮选尾矿中检测不到。