不同胺/铵阳离子在高岭石(001)面吸附的密度泛函计算

为探索阳离子胺盐和季铵盐在高岭石表面的吸附机理,构建了CH6N+(伯胺阳离子)、C_2H_8N~+(仲胺阳离子)、C3H10N+(叔胺阳离子)及C4H12N+(季铵阳离子)4种不同胺/铵阳离子构型,并采用密度泛函理论对4种阳离子在高岭石(001)面的吸附进行模拟计算。模拟结果表明,4种阳离子CH6N+,C_2H_8N~+,C3H10N+及C4H12N+在高岭石(001)面都能发生稳定吸附,其较为稳定构型的吸附能分别-125.385,-126.154,-128.654和-109.711 k J/mol;但3种胺阳离子与季铵阳离子的吸附机理不同:胺阳离子在高岭石(001)面的吸附是静电引力和氢键的共同作用,季铵阳离子则只通过静电引力作用与高岭石(001)面发生吸附。静电引力作用是导致不同胺/铵阳离子在高岭石(001)发生吸附的主导作用。     

关于季铵盐萃取铀多核萃合物的研究

关于季铵盐从碳酸钠溶液中萃取铀的反应,前人均认为: UO_2(CO_3)_3~(4-)+4R_4NCl(?)(R_3N)_4UO_2(CO_3)_3+4Cl~-萃合物中铀与季铵的摩尔比为1:4,含0.1M季铵盐的有机相萃取铀的理论饱和容量为5.95克/升。在铀水冶碱法工艺中,以季铵盐(甲基三烷基(C_9～C_(11))氯化铵、熔点40±5℃、闪点168℃燃点189℃,d_4~2:0.8232,M:410～418)的煤油溶液(加入仲醇(C_(12)～C_(16))作添     

某钙基膨润土制备高粘度有机膨润土工艺研究

以某钙基膨润土钠化提纯料浆为原料,通过添加复配季铵盐和有机助剂制备了粘度为6.4Pa·s的高粘度有机膨润土.其最佳制备工艺条件为:复配季铵盐与钠化提纯膨润土阳离子交换总量摩尔比为1:1、有机助剂A添加量为钠化提纯膨润土质量的4.78%、总反应时间2h、反应体系pH值6～8、反应温度75～80℃.且有机助剂A在加复配季铵盐1.5h后加入.     

凝胶型有机膨润土制备工艺研究

以某钙基膨润土提纯钠化料浆为原料,通过添加复配季铵盐和有机助剂制备了粘度为6.5 Pa·s的高粘度凝胶型有机膨润土;最佳制备工艺条件为:复配季铵盐用量与提纯钠化膨润土阳离子交换量mol比为1:1、有机助剂添加量为提纯钠化膨润土质量的4.78%、总反应时间2 h、反应体系pH值6~8、反应温度75~80℃,其中有机助剂在加入复配季铵盐反应后1.5 h加入.     

关于季铵盐萃取铀的多核萃合物(R_4N)_2U_3O_(10)的研究

本文研究了用手铵盐-仲醇-煤油溶液从弱碱性(或近中性)溶液中萃取铀的机理。用斜率法和连续变量法证明,在水相组成为铀0.01M、碳酸氢铵0.043—0.056M、pH=7.2—7.8时,季铵盐萃取铀的多核萃合物的组成为(R_4N)_2U_3O_(10)。提出了萃取反应机理,并测定了该萃合物的红外光谱图。     

长烷烃链季铵盐对OMMT晶片层间结构的影响

采用长烷烃链季铵盐改性蒙脱土(MMT),制得有机蒙脱土(OMMT),X-射线衍射(XRD)、傅里叶变换红外光谱(FTIR)和扫描电子显微镜(SEM)表明:随着季铵盐用量、碳原子数、烷烃链数的增加,OMMT晶片层间距d001增大;季铵盐烷烃链从1条增加到2条,d001急剧增大,继续增加到3条时,d(001)增幅则较小,季铵盐中卤素取代基对d(001),影响不失;OMMT的d001于季铵盐用量为100-150mmol/100gMMT时趋于稳定,d(001)由MMT的1.26nm增加到OMMT的2.11nm(单烷烃链季铵盐)、3.98nm(双烷烃链季铵盐)、4.09nm(三烷烃链季铵盐);季铵盐阳离子在OMMT晶片层间的排列方式与口(季铵盐阳离子与OMMT晶片层上下层面的夹角)、L(季铵盐阳离子链长)、d(0)(OMMT两个晶片实际层间距)及季铵盐中氮原子构型有关,单烷烃链季铵盐阳离子在OMMT晶片层间采取平卧或者半倾斜排列方式,双、三烷烃链季铵盐阳离子在OMMT晶片层闻采取倾斜排列方式,尤其当α=90°时,季铵盐阳离子在OMMT晶片层间采取近似直立排列方式.     

基于水化膜弱化促进煤泥脱水机理及试验研究

煤泥颗粒表面水化是煤泥脱水困难的重要因素之一,通过弱化煤泥颗粒表面水化膜促进煤泥高效脱水是一种新的技术方法。为掌握基于弱化水化膜促进煤泥脱水机理,采用密度泛函理论方法模拟了不同长链烷基季铵阳离子(表面活性剂)在煤泥水主要矿物颗粒表面的吸附,通过对吸附构型、Mulliken键布局及电荷的分析,研究了水及药剂在高岭石(001)面、α-石英(001)面和蒙脱石(001)面的吸附机理;通过开展煤泥脱水试验和接触角测试,探讨长链烷基季铵盐药剂对煤泥水分和表面润湿性的影响规律。结果表明,水分子在不同种类矿物(001)面的吸附稳定性顺序为石英>高岭石>蒙脱石,石英对煤泥脱水影响大于高岭石和蒙脱石;长链烷基季铵盐药剂在矿物表面的吸附稳定性明显高于水分子,说明药剂与水分子的竞争吸附作用顺序是蒙脱石>石英>高岭石;长链烷基季铵盐与几种矿物(001)表面吸附均是以静电引力为主,弱氢键为辅。随着长链烷基季铵盐药剂用量的增加,煤泥滤饼水分先减少后增加,当药剂用量为500 g/t效果最好,水分降低2.25%以上;随着药剂用量和链长的增加煤泥表面疏水性显著增加。控制药剂用量是实现高效煤泥脱水的技术关键,添加适量的表面活性剂有利于弱化矿物表面的水化膜,过量长链烷基季铵盐阻碍煤泥脱水。     

用季铵盐从碳酸铵、硫酸铵碱性解吸液中萃取分离铀、钼

本文提出了以季铵盐为萃取剂,在加入过氧化氢的条件下,从(NH_4)_2CO_3-(NH_4)_2SO_4溶液解吸某铀水冶厂含铀、钼树脂所得的料液中分离铀、钼的新方法。结果表明,当料液中含铀4—5g/L、钼～2g/L时,季铵盐浓度为0.15mol/L,加入过氧化氢0.8％(v/v),相比(有/水)为1/4,经一段萃取,钼的萃取率可达97.9％,负载有机相中含铀小于0.1g/L。     

用TOPS99，PC88A，Cyanex 272和它们的混合物从硫酸盐溶液中萃取Cd（Ⅱ）：Reddy B．R．，et al．，Hydrometallurgy

研究了用基于有机磷的萃取剂——TOPS99，PC88A和Cyanex 272对硫酸盐溶液中Cd(Ⅱ)的萃取。Cd(Ⅱ)的萃取率随着水相平衡pH值和萃取剂浓度的增加而增大。用有机磷萃取剂萃取Cd(Ⅱ)涉及阳离子交换机理，形成金属与萃取剂为1：3(物质的量的比)的萃合物。     

新型不对称型双子季铵盐阳离子捕收剂的合成及其对石英的浮选行为研究

针对铁矿石反浮选工艺采用传统阳离子捕收剂十二胺时存在分选效果差、难溶于水等问题,制备了4种含有不同碳链长度的不对称型双子季铵盐捕收剂1-M-12、1-M-14、1-M-16、1-M-18。单矿物浮选结果表明,在相同试验条件下,新型不对称型双子季铵盐阳离子药剂中1-M-14、1-M-16、1-M-18的捕收能力大于传统阳离子捕收剂十二胺,具有浮选效率高、受pH影响小的特点。动电位测试结果与红外光谱分析测试结果表明,新型药剂与石英之间存在物理吸附和氢键作用。     

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。