硫酸盐体系中硫化镍阳极电化学溶解动力学

本文采用旋转圆盘电极并结合线性扫描、恒电位单阶跃、恒电流电解、循环伏安等电化学测试方法综合考察了 Ni_3S_2在硫酸盐溶液中的阳极电化学溶解动力学规律,查明了其活性溶解反应的控制步骤;并利用 Au-Hg 齐环电极检测到中间硫氧离子的还原电流,提出了 Ni_3S_2阳极分段溶解逐步氧化的反应机理。求取了反应速度常数、固相扩散系数、反应活化能等动力学参数。     

乙硫氮体系脆硫锑铅矿的浮选行为及电化学研究

研究了以乙硫氮为捕收剂时脆硫锑铅矿的浮选性质。在酸性介质中脆硫锑铅矿具有良好的可浮性; 但在碱性介质中(pH>8.0), 可浮性急剧下降; 在pH=11.0的高碱条件下, 无论矿浆电位如何变化, 脆硫锑铅矿的可浮性都很差。pH=6.0, 脆硫锑铅矿的可浮电位区间为0～0.7 V, 电位范围较宽; pH=9.18时, 可浮电位区间则为0～0.5 V。采用循环伏安电位扫描研究方法, 研究了乙硫氮在脆硫锑铅矿表面的电化学作用机理, 在其表面没有氧化形成四乙基二硫化秋兰姆(TETD 或D₂)分子; 电极电位从-0.25 V左右开始就在脆硫锑铅矿产生了化学吸附。在乙硫氮存在时, 从0.35 V开始乙硫氮与脆硫锑铅矿相互作用明显, 电位增加到0.75V附近存在明显的氧化峰, 试验结果表明在脆硫锑铅矿表面有PbD₂、 SbOD形成产生。电化学试验结果与浮选试验结果能较好地对应起来。     

脆硫锑铅矿矿浆电解过程硫的形成机理

通过脆硫锑铅矿矿浆电解渣工艺矿物学研究和有关热力学和电化学的分析，探讨元素硫形成及氧化机理，结果表明，元素硫是脆硫锑铅矿与Fe^3 接触氧化的反应产物，脆硫锑铅矿分解生成H2S再被Fe^3 氧化的反应是次要的。矿浆电解时，元素硫在阳极上基本不被氧化。     

电化学处理对铁矿物结构与其浮选特性的影响

试验研究了苏联马格尼托戈尔斯克矿床含氧化铁矿石矿浆,浮选前电化学处理(电极电压为5～15伏,作用1～3分钟)的影响。浮选效率的提高,归因于捕收剂在有用矿物上固着量的增加,导致提高了矿物表面疏水性之故。试验证明了固体颗粒上铁的氢氧化物的电化学溶解以及氧化还原电位的变化。     

硫脲浸金过程中亚硫酸的促进作用

通过线性极化、循环伏安电位扫描、恒电流阶跃等电化学测试方法 ,研究了纯金在硫脲溶液中的溶解过程 ,在亚硫酸存在的硫脲溶液中 ,金阳极氧化的峰电位负移 ,峰电流增大 ,促进金的阳极过程 ,确定金阳极过程的钝化原因是金电极表面吸附元素硫所致。电化学研究表明 ,硫脲体系中亚硫酸促进金阳极过程的机理是亚硫酸参与了反应过程 ,与硫脲的氧化产物发生了还原反应 ,减少了硫脲的不可逆降解 ,提出了亚硫酸在硫脲浸金过程中的电化学还原—催化溶解机理。     

电解法分离铟与铊

人們很早就观察到,铟电解只能粗略地或部分地和它的共生金属分离。克萊納脫和特雷依尔証实,在标准电位次序中位于鋅之前的金属不能和铟分离,虽然In~(+3)离子和Zn离子的标准电位相差0.43伏以上。最近作者詳細地研究了铟的电化学行为,并且确定只有一价狀态的铟可以电析出来,In~(+1)离子是非常容易氧化的,其对标准氫电極的氧化还原电位約(?)0.4伏。当陰極区域和陽極区域用隔膜很好地隔开时,金属铟成很好的結晶狀态析出,并且电流效率很高。如于45°下,电解1％濃度的In_2(SO_4)_3溶液(pH=2.44),     

氯化物介质中黄铜矿和铁闪锌矿的电化学行为

本文分别运用三电极体系和双电池系统在氯化物体系中对黄铜矿的阳极电化学行为和不同的硫化矿电极对之间的微电池作用进行了研究。在三电极体系中，动电位扫描结果表明，黄铜矿的阳极氧化与电解质有关，但更多的依赖于电位。恒电位实验得出，高电势与低电势下，黄铜矿的溶解显著的不同。阳极溶解过程产生了中间产物。双电地体系测出了不同电极对之间的微电池电流，表明微电池相互作用在硫化物混合精矿的浸出过程中起了重要作用。     

硅氟酸溶液中方铅矿的阳极氧化动力学研究

用动电位扫描法测量不同条件下硅氟酸溶液中石墨电极上方铅矿的阳极氧化曲线 ,研究方铅矿的阳极氧化动力学。结果表明 ,方铅矿的阳极氧化曲线明显地分为 3段 ,氧化区di/dφ >0 ,传质区di/dφ=0 ,另一氧化过程 ,di/dφ >0。交换电流密度i0 随着温度的增加而增大 ,电化学传递系数 β的平均值为 0 16。搅拌速率、矿浆液固比对换电流密度i0 有较大的影响     

镁合金正交优化阳极氧化膜耐蚀性能研究

采用正交设计,获得优化的AZ91D镁合金阳极氧化膜。通过SEM、XRD、极化曲线和浸泡试验方法分别研究了AZ91D镁合金阳极氧化膜的表面形貌、结构和成分,以及膜的耐蚀性。结果表明:镁合金阳极氧化膜具有多孔结构,孔径较小且分布均匀;阳极氧化膜主要由MgF2和Al2SiO5组成;阳极氧化膜击穿电位与腐蚀电位的差值ΔE值高达980mV;35℃下,在3 5%NaCl中性溶液中经48h浸泡,阳极氧化膜未出现明显的腐蚀痕迹。     

硫脲-亚硫酸体系中金电极的电化学动力学研究

采用Tafel曲线的电化学测试方法 ,研究了有无亚硫酸存在时 ,金电极在硫脲体系阳极过程的动力学。试验结果表明 ,硫脲浓度的增加可以提高金电极的腐蚀电流密度 ,有无亚硫酸时 ,金在硫脲体系溶解的活化能分别为5 9.11kJ/mol和 48.47kJ/mol。理论计算表明 ,在 2 5℃下 ,添加 5× 10 - 6 mol/L的亚硫酸可使硫脲阳极氧化速率提高73 .3倍。而在有无亚硫酸存在时 ,体系温度由 2 98K提高至 3 2 3K ,金在硫脲体系中的阳极溶解速率分别提高 4.5 5倍和 6.3 7倍     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

2014 second batch of rare earth quota released

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矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586