以吸附阴极溶出伏安法同时测定微量铀(Ⅳ)和锌(Ⅱ)

《Talanta》2 0 0 0年第 5 2卷第 6期发表了 Ki- Won Cha等人关于以吸附阴极溶出伏安法同时测定微量铀 ( )和锌 ( )的论文。测定方法基于铀 ( ) -试铝灵 (3- [双 (3-羧 - 4 -羟 -苯基 )亚甲 ]- 6 -氧代 - 1 ,4-环己二烯 - 1 -羧酸三铵盐 )配合物有效沉积在悬汞电极界面上所产生的电化学反应。使用 CV- 5 0 W伏安分析仪 ,1 0 m L的标准极谱池和三电极系统。悬汞电极为工作电极 ,银 /氯化银电极为参比电极 ,铂丝为对电极。支持电解质为 0 .1 mol/L醋酸钠。作者对铀 ( ) -试铝灵配合物在汞电极的吸收光谱、吸附溶出伏安图、支持电解质电解…     

工艺参数对活性焦烟气中联合脱硫脱汞性能的交互影响

在固定床吸附反应器上,考察了温度、SO2浓度、NO浓度、O2浓度等工艺参数对活性焦联合脱硫脱汞性能的影响。结果表明：温度在130～190 ℃内,温度降低有利于活性焦联合脱硫脱汞;随着SO2浓度提高,活性焦对SO2吸附量呈增大趋势;基准工况（BL）+1 500 mL/m3 SO2体系下,活性焦对单质汞(Hg0)单位吸附量比在BL中下降33%,SO2与单质汞在活性焦表面存在竞争吸附,SO2对活性焦对单质汞吸附能力有明显的抑制作用;NO与O2生成具有氧化性的NO2和O原子,增强了单质汞的氧化,BL+400 mL/m3 NO体系中活性焦的单质汞单位吸附量比在BL中升高24%;BL+SO2+NO体系中,活性焦的单质汞吸附能力比在BL中下降38%。     

锌/铜/汞2-巯基苯并噻唑配合物的高压液相色谱研究

研究锌、铜、汞的2-巯基苯并噻唑配合物的高压液相色谱行为，试验多种固定相和流动相对金属配合物的分离情况，给出锌、铜、汞离子的最佳分离与测定条件。结果表明，Zn，Cu，Hg的最低检测限分别为25ng，10ng和40ng。Zn，Cu，Hg4次进样的变异系数分别为1．54%，2．65%和1．58%。     

CL-TBP萃淋树脂分离富集--全差示光度法测定含铀废水中微量钍

在 4mol/ L 硝酸介质中 ,在酒石酸存在下 ,用 CL- TBP萃淋树脂吸附钍 ,再用 4mol/ L 盐酸解吸 ,在草酸、尿素掩蔽下 ,钍与偶氮胂 形成稳定的红色络合物。络合物最大吸收波长 6 6 8nm,可稳定 2 .5 h。摩尔吸光系数达 1 .2 7× 1 0 5 L / (mol· cm )。在全差示分光光度计上 ,调节不同参数的微电流 ,实现了高精度的测量。本法比普通光度法灵敏度提高 1 0倍 ,方法精密度优于± 5 % ,回收率99.0 %～ 1 0 6 %。     

汞精矿矿浆悬浮电解渣中汞相分析的方法

汞相的化学分析方法,目前仅分析金属汞和硫化汞两相。本文研究了汞精矿矿浆悬浮电解渣中氯化汞、氧化汞,金属汞和硫化汞四相的分离条件及简捷准确的测定方法。此法基于用无水乙醇浸取氯化汞,离心分离,不溶物用10%硫酸溶液浸取氧化汞,离心分离;不溶物用硝酸(2+1)溶液浸取金属汞,离心分离;不溶物转入50毫升锥形瓶中,用逆王水(1+1)溶液,在电热板上微沸10分钟溶浸硫化汞。分离后所得的含汞溶液均用铜试剂容量法     

钽反萃取液中微量铌的自动测定——流动注射—树脂在线分离—分光光度法

采用流动注射进样 ( 10 μL) ,用 1mol/ L HCl 10 g/ L HF溶液作为上柱液 ,通过阴离子交换树脂使大量钽吸附 ,微量铌流出 ,含铌流出液在配合剂存在下与氯代磺酚 S混合并反应 ,形成的多元配合物 ,停流 5min后在 62 0 nm和 38℃条件下进行铌的吸光度测定。方法可用于钽反萃取液中 ρ( Nb2 O5)为 0 .0 0 5～ 0 .0 5g/ L的测定。线性相关系数为 0 .999,样品的相对标偏为± 6.1% ,回收率为 90 %～ 110 % ,分析速度约为 10次 / h     

改性膨润土处理含汞废水研究

研究了改性膨润土在不同条件下处理含Hg2 废水的能力。结果表明 ,在温度为 2 5℃、pH值为 8～ 9、吸附时间为 60min的条件下 ,用 40 %的AlCl3溶液改性过的膨润土可将含Hg2 废水 (初始浓度为 1.46mg/L)处理到Hg2 剩余浓度为 0 .0 3 5 1mg/L ,达到国家规定的排放标准。     

负载型MnOx/Al2O3催化剂低温下脱除烟气中单质汞特性

针对燃煤烟气中单质汞(Hg0)因不溶于水很难去除的问题,以浸渍法制备的负载型MnOx/Al2O3为催化剂,在固定床实验台架上,考察前驱体、负载量、煅烧温度、反应温度和烟气成分对Hg0的催化氧化影响;采用N2吸附/脱附、扫描电镜(SEM)和X射线衍射(XRD)对催化剂进行表征。结果表明,硝酸锰浸渍催化剂的脱汞效率优于醋酸锰浸渍催化剂,催化剂的主要活性成分为MnO2;MnOx的表面形貌和存在形态是硝酸锰浸渍催化剂脱汞性能优于醋酸锰浸渍催化剂的主要原因。较低负载量下,前驱体对脱汞效率的影响较大;随着负载量的增加,其差异逐渐缩小。MnOx/Al2O3催化剂的最佳反应温度和煅烧温度分别为150 ℃和400 ℃。烟气中的O2能够补充催化剂消耗的晶格氧,促进Hg 0的催化氧化;NO,SO2和H2O均对脱汞产生抑制作用,其中SO2的抑制作用最大,H2O次之,NO最小。     

新试剂1-(4-硝基苯基)-3-(2-苯骈咪唑基)-三氮烯的合成及其与汞(Ⅱ)反应的分光光度研究

合成了1—(4—硝基苯基)—3—(2—苯骈咪唑基)—三氮烯(NPBMT)。提出了灵敏的用NPBMT分光光度测定痕量汞的新方法。在Hg(Ⅱ)与NPBMT比为1:2的条件下,2—121μgHg(Ⅱ)/25mL服从比尔定律,表观摩尔吸光系数为2.60×10~5L·mol~(-1)·cm~(-1),加入μg级Hg(Ⅱ)的回收率为98.01—101.3%。受污染的自来水中痕量Hg(Ⅱ)可用本法测定。     

Au掺杂MnO2催化剂表面Hg0与Cl吸附状态理论研究

采用基于第一性原理的Materials Studio(MS)软件中量子力学模块CASTEP,对催化氧化烟气脱汞过程中Hg0与Cl在Au掺杂改性前后MnO2 (110)表面各个吸附位点的吸附状况进行了计算机模拟.结果表明:掺杂有利于改善Cl和Hg0在MnO2表面的吸附状态,Hg0与Cl均优先吸附于催化剂表面的氧活性位点上;烟气中的Cl和Hg0在MnO2表面不会发生竞争吸附,且Cl会优先于Hg0占据催化剂表面的含氧活性位点.     

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     

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     

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     

唐口煤矿深部复杂开采工作面瓦斯分源涌出规律研究

研究工作面瓦斯涌出规律对工作面瓦斯治理有重要意义。为了得到唐口煤矿深部3号煤层复杂开采条件下工作面回采时期瓦斯涌出时空演化规律,选取6304工作面作为对象,采用实测方法研究6304工作面瓦斯涌出规律。结果表明:6304工作面瓦斯涌出量为6.534 m³/min,其中煤壁占34.27%,落煤占29.62%,采空区占36.11%;沿工作面倾向由低到高,瓦斯浓度整体为上升趋势,其中1—76号架工作面瓦斯浓度小于0.20%,76—102号架瓦斯浓度上升明显,最大为0.387%;上隅角的后部采空区是工作面的瓦斯主要涌出源,上隅角1号测点瓦斯浓度0.78%,上隅角周边3号、5号、7号、8号、9号测点瓦斯浓度平均为0.643%;周期来压时,上隅角瓦斯相对平时较高。研究为针对性的瓦斯分源监控与灾害防治提供基础。