共查询到18条相似文献，搜索用时 187 毫秒
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研究了铜精矿催化加压浸取净化除铁后 ,料液中铜镍的萃取分离及串级模拟实验。采用LIX984萃取剂 ,在料液 pH =4.0时铜镍分离效果较为理想。除铜后的料液 ,用P2 0 4 萃取富集镍。经硫酸反萃的溶液可直接用于铜镍的电解精炼。 相似文献
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从石煤酸浸液中萃取钒的工艺研究 总被引：7，自引：0，他引：7
研究了三正辛胺从石煤酸浸液中的萃取钒的工艺过程，从萃取和反萃的pH值、相比、有机组组成、澄清时间等方面进行了详细试验。研究表明：用三正辛胺萃取钒时，其萃取率可达98％以上；而且易反萃，用0．5M Na2CO3反萃时，反萃率为99．9％。经萃取后。浸出液中的钒可由每升几克富集到每升数十克以上，有利于后续的提钒工艺。 相似文献
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探讨了钴矿石浸出液中Co、Cu、Fe的萃取分离 ,以及不同萃取剂萃取上述元素时的影响因素。提取液用P2 0 4 、LIX984 和正辛酸分别萃取Fe、Cu和Co ,萃取率分别为 99.9%、99.4%和 98.1%。成功地实现了复杂钴矿石中Co、Cu、Fe的分离与提纯 相似文献
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基于0．02mol／L HCl介质中，痕量钴(Ⅱ)对重铬酸钾氧化偶氮胂Ⅲ褪色反应的催化作用，建立了测定痕量钴(Ⅱ)的动力学光度法。钴(Ⅱ)质量在0～4．0μg/L范围内服从比尔定律，方法检出限为0．076μg/L，在25mL溶液中，测定0．1μg钴(Ⅱ)的相对标准偏差为3．8％(n=11)。讨论了酸度、反应物浓度、温度、反应时间、干扰离子等因素的影响。研究了反应的最佳条件，并测定了一些动力学参数。催化反应的表观活化能为40．73kJ／mol。此法可用于井水、蜂蜜和维生素B12中钴(Ⅱ)的测定，相对标准偏差为1．8％-5．7％，标准加入回收率为99．6％～104．2％。 相似文献
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传统的液液萃取技术主要采用与水不相溶的有机溶剂作萃取剂,这种异相萃取的传质速率一般较低,需反复振荡或多次萃取.本文建立了以乙腈-硫酸铵-水的双水相萃取体系高效液相色谱法测定地下水中苯并(a)芘和苯并(e)芘的方法,以密度比水小的乙腈为萃取剂,将其与水样混合(互溶)获得乙腈-水体系,然后加入硫酸铵,溶液澄清、分相后取上层有机相(乙腈)进样分析.考察了萃取剂的选择、双水相的形成条件、离子强度以及pH等对测定结果的影响.两种化合物线性范围为2.00～ 400.00 ng/mL,相关系数大于0.999.方法检出限为0.012～0.020 ng/mL,平均回收率为94.6％～97.3％,相对标准偏差为1.3％ ～2.5％.与传统萃取方法相比,该方法具有操作流程简单、快速的特点,可实现对野外环境水样进行原地样品前处理. 相似文献
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某厂湿法镍精炼生产线处理原料杂质含量较高,特别是钙、镁含量,随着处理量的增加,钙、镁在后续系统中富集,达到饱和析出结晶,影响生产线的稳定运行。本文在总结对比化学沉淀法、浓缩静止法、离子交换法、萃取法等常用除钙、镁方法的基础上,结合现有萃取工艺,采用P204萃取剂对硫酸镍溶液进行多级逆流萃取,并分析P204在不同pH值、不同料液浓度条件下的萃取效果。结果表明,采用P204萃取C272萃余液时,随着萃取级数的增加,萃钙率呈波动上升趋势,在六级逆流萃取后达到最大值;萃镁率随着级数增加,呈稳定上升趋势,十级逆流萃取后保持98%左右。在其他试验条件相同的情况下,pH值越低,钙、镁离子萃取率越高,铁、钴离子萃取率越低。当溶液中镍离子较高时,P204萃取时镍先于钙、镁沉淀,且镍去除率较高,反应后溶液较为粘稠,过滤性能较差,因此对镍离子较高的溶液进行萃取不具有实际操作意义。 相似文献
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C18固相膜萃取-气相色谱法测定饮用水中12种有机氯农药 总被引：13，自引：10，他引：13
利用C18固相萃取膜提取水样，气相色谱法（电子捕获检测器）测定饮用水中12种有机氯农药。对洗脱液、水样pH值、萃取压力等条件进行了优化选择，并与液-液萃取做了比较。结果表明，与液-液萃取相比，固相膜萃取具有操作简单、富集倍数高、节省溶剂和耗时短等优点，是萃取水中有机氯农药的有效方法。12种有机氯农药的回收率为85．97％～127．7％，相对标准偏差（RSD，n=5）为4．74％～12．2％，方法检出限为0．014～0．047μg/L。 相似文献
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Z. Yang W. Guo Y. Fan C. Lin M. He 《International Journal of Environmental Science and Technology》2013,10(2):275-282
The remobilization of iron, manganese, cobalt, cadmium, copper and zinc in the pore water of estuarine sediment cores at Yingkou was assessed using diffusive equilibrium in thin films and diffusive gradients in thin films techniques. A relatively anoxic system (+33.7 to ?224.1 mV) in the sediment cores might cause the reductive release of iron, manganese and cobalt into pore water from the estuarine sediment. High-average concentrations of iron (47.85 μg ml?1) and manganese (3.81 μg ml?1) were observed using diffusive equilibrium in thin films on the sediment core, but the concentration of cobalt (18.02 ng ml?1) was relatively low. A strong correlation between iron and cobalt was observed based on the vertical profiles of the metals. Manganese and iron were more readily released from the solid phase to the solution. The peak cobalt, copper and zinc concentrations were observed in the upper layer (2–4 cm) measured using diffusive gradients in thin films. However, the peak iron, manganese and cobalt concentrations were located in the deeper layer (≥7 cm). In addition, the concentration profiles measured using diffusive gradients in thin films of cobalt, copper and zinc were independent of the iron, manganese and cobalt distribution with respect to depth. 相似文献
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《Applied Geochemistry》1994,9(3):337-350
Column tests were conducted to determine the leachability of As, Cd, Cu, Fe and Pb from copper smelter flue dust that had been treated by the Cashman Process in an effort to recover metals while rendering the residue inert. Between 100 and 300 μg/l As [predominantly As (V)] leached from the residue from a batch-reactor test, while between 1000 and 1400 μg/l As leached from residue from a continuous-reactor test. Electron microprobe analyses of the two materials identified scorodite (FeAsO4·2H2O) as the principal As-bearing phase. The pHs of leachate from the batch-and continuous-reactor residues were approximately 5.0 and 4.0, respectively. Cadmium and Cu leachate concentrations decreased through the tests, while Pb equilibrated at approximately 200 and 1300 μg/l for the batch and continuous residues, respectively. The measured Eh did not agree with the Eh calculated from either the As(III)/As(V) or Fe(II)/Fe(III) couple. Modeling of system chemistry using MINTEQA2 indicated that scorodite controlled the As concentration of the leachate. The variability of leachate As and metal concentrations between the batch-and continuous-reactor residues indicates that the process conditions failed to produce residues of satisfactory stability. 相似文献
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X射线荧光光谱法测定富含硫砷钒铁矿石中的主次量元素 总被引：3，自引：3，他引：0
以钴(钴玻璃粉形式)作内标元素,准确测定全铁含量;加入保护剂硝酸铵和稳定剂碳酸锂,使硫转化为硫酸盐,有效地防止硫的挥发损失。通过条件实验,确立了样品熔融温度和钴玻璃粉的用量。选择经筛选的仪器测定条件,用X射线荧光光谱法同时测定铁矿石中TFe、SiO2、CaO、MgO、Al2O3、TiO2、P、S、Mn、V2O5、As、K2O、Na2O、Cu、Ni等15种主次量元素。采用干扰曲线法对几乎完全重叠的TiΚβ谱线与VΚα谱线进行谱线重叠校正,用理论α系数法校正基体效应。建立的方法可以准确测定全铁和质量分数高达5.29%的S。采用多种标准物质和人工配制标准物质制作工作曲线,可以测定质量分数为5.00%的V2O5及0.1%的As,测定值与标准值符合较好,除低含量钠外方法精密度(RSD)<3.5%,分析误差符合实验质量要求。本法可以快速、准确地测定含砷的钒钛铁矿及含硫高的铁矿石中的主次量元素,满足了日常生产对铁矿石中硫和钒的测定要求。 相似文献
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F. Khanramaki A. S. Shirani J. Safdari R. Torkaman 《International Journal of Environmental Science and Technology》2018,15(7):1467-1476
This paper presents a comprehensive study of the liquid–liquid extraction of uranium from 0.2 M sulfuric acid solution by tertiary amine (Alamine 336) and kerosene as an extractant and a diluent, respectively. For this purpose, the effects of operating parameters on the uranium extraction efficiency such as Alamine 336 concentration, contact time, initial aqueous phase pH, sulfate ion concentration, temperature and stripping process by different agents are investigated. The Gibbs energy change (ΔG), enthalpy change (ΔH) and entropy change (ΔS) have been determined as thermodynamic parameters to prove exothermic and spontaneous reaction. Also, equilibrium constants, reaction equation and stoichiometric coefficients for uranium extraction with Alamine 336 in sulfate medium are specified. The proposed procedure can be applied to the recovery of uranium from low-grade ore processing and from wastewater in the different stages of the nuclear fuel cycle. 相似文献
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铜转炉渣中钴的载体矿物在酸解中的行为 总被引：2，自引：0，他引：2
用光学显微镜、X射线衍射谱、扫描电子显微镜、X射线能谱和X射线波谱并辅以化学物相分析进行了铜转炉渣及其加工产物的工艺矿物学研究。查明了铜转炉渣主要由铁橄榄石和铁酸盐（磁铁矿）以及少量玻璃相组成，铜呈冰铜相主要嵌布于铁酸盐之间，钴则主要以类质同象形式取代铁橄榄石和磁铁矿晶格中部分Fe^2 ，作为氧化物富集其中。在酸解中铁橄榄石和铁酸盐均发生分解，使冰铜相得以解离，铁和钴则转化为可溶性硫酸盐，随后被浸出。铁酸盐分解不完全是影响钴浸出率的主要原因。 相似文献
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氨基膨润土对铜镍镉污染土壤的钝化修复研究 总被引：1，自引：0，他引：1
采集土壤,加入铜、镍和镉制成重金属污染土壤。以四乙烯五胺改性膨润土和膨润土原土作为修复剂,通过模拟酸雨和混合提取剂提取有效态重金属,评价膨润土和氨基膨润土对土壤中铜、镍、镉的钝化效果。结果表明:p H=3. 5的模拟酸雨对各污染土壤中重金属离子的提取率均在0. 1%以下。混合提取剂对污染土壤中有效态金属的提取能力比模拟酸雨强很多。添加膨润土原土和氨基膨润土均能钝化土壤中的铜、镍和镉,氨基膨润土上嫁接的氨基对金属有络合作用,因而比膨润土原土对铜、镍和镉具有更强的钝化能力。综合评价表明氨基膨润土是一种对铜、镍和镉污染土壤具有应用前景的钝化修复材料。 相似文献
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A flow sheet was developed to recover thorium from Egyptian monazite sands. The results of a detailed investigation on the extraction and stripping of thorium in the hydrous oxide are obtained after alkaline dissolution followed by leaching with alkaline carbonate solutions. This cake was dissolved in 4 M HNO3 and thorium was extracted selectively by a counter-current extraction system using a mixer–settler contactor and Aliquat-336 in kerosene as extractant. The results show that 2 h of continuous operation are necessary to reach the steady state condition for the process. The extraction efficiency is found to be 80% and the stripping efficiency is 82%. 相似文献