碱性溶液中砷萃取分离研究

发布时间：2018-01-14 13:18

本文关键词：碱性溶液中砷萃取分离研究　出处：《江西理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：就高砷炼铜烟灰资源综合利用,此前的研究工作提出了碱浸脱砷预处理工艺,该工艺能实现良好的碱浸脱砷效果,并能从碱浸渣中高效回收铜、铅、锌等有价金属。针对碱浸液中砷(III)的分离与富集问题,本文研究采用了CO32-型三辛基甲基氯化铵(Tri-n-octylmethyl-ammonium chloride,TOMAC)有机相萃取硫代亚砷酸的新工艺,可以实现由高砷烟灰碱浸液中直接提取砷。新工艺为高砷烟灰短流程资源化及砷无害化奠定了基础。本文的研究内容如下:基于热力学计算,研究了水溶液中砷溶解行为。基于此,对砷萃取剂进行了筛选。为提高砷萃取能力,对所选的TOMAC,将Cl-型有机相转型为CO32-型。研究制定了TOMAC有机相转型的较优工艺。基于红外光谱,对转型前后TOMAC有机相结构进行分析比较。基于TOMAC有机相CO32-转型实验,通过热力学计算,分析了AsIII-S-H2O体系中砷赋存的离子形态,探讨了其与溶液p H值之间的关系。结果发现,在高碱条件下,HAs OS22-可能是As III硫化反应的最主要的产物。基于碱浸模拟溶液实验,测定了CO32-型TOMAC有机相(30%TOMAC+15%仲辛醇+磺化煤油)自含As III 9.69×10-2 mol/L、Na OH 0.5 mol/L的水相料液中萃取硫代亚砷酸的饱和容量。萃取剂与硫代亚砷酸可能按摩尔比2:1缔合。基于碱浸模拟溶液实验,研究确定了CO32-型TOMAC有机相萃取硫代亚砷酸的较优工艺条件:有机相组成,30%TOMAC+15%仲辛醇+磺化煤油;水相料液组成,0.5 mol/L Na OH+9.69×10-2 mol/L As III;萃取温度,室温;萃取相比,O/A=1/l。在上述条件下,AsIII单级萃取率为85.3%。经4级逆流萃取,萃余液中As III浓度可降至1.34×10-3 mol/L以下,萃取率可达98.5%以上,初步达到碱性溶液有效脱砷目的。负载有机相经1.0 mol/L Na Cl+2.0 mol/L Na OH混合溶液以相比O/A=1/l反萃,单级反萃率可达89.8%。当反萃相比选择2/1,经6级逆流反萃,理论反萃率可达98%以上。进一步基于红外光谱,分析比较了有机相经“转型-萃取-反萃”后结构变化。
[Abstract]:Comprehensive utilization of high arsenic copper smelting dust resource, research work had made alkaline leaching pretreatment for arsenic removal process, the process can achieve good effect of removing arsenic alkali leaching, and efficient recovery of copper from slag, alkali leaching of lead, zinc and other valuable metals. The alkaline leaching solution of arsenic (III) and enrichment the problem of separation, this paper uses CO32- type three octyl dimethyl ammonium chloride (Tri-n-octylmethyl-ammonium chloride TOMAC) new technology of organic phase extraction thioarsenous acid, can be achieved by the high arsenic ash alkaline leaching solution of direct extraction of arsenic. Laid the foundation for the new technology of high arsenic ash short process resources and harmless. The contents of arsenic this paper is as follows: Based on the thermodynamic calculation of arsenic dissolution behavior in aqueous solution. Based on this, the arsenic extraction agent were screened. In order to improve the extraction ability of arsenic, selected TOMAC, Cl- type organic phase transition to CO32-. To study the development of TOMAC The organic phase transition of the optimal process. Based on the infrared spectra of TOMAC before and after transformation of organic phase structure analysis. TOMAC CO32- organic phase transition experiments based on thermodynamic calculation of the ion forms of arsenic occurrence in AsIII-S-H2O system, and discusses the relationship between P and solution H value. The results showed that in high alkali under the condition of HAs OS22- As III may be the main product of the vulcanization reaction. The alkali leaching solution of simulated experiments based on the determination of CO32- type TOMAC organic phase (30%TOMAC+15% octanol + kerosene) from As containing III 9.69 * 10-2 mol/L, the saturated capacity of aqueous feed solution OH 0.5 Na mol/L extraction thioarsenous acid.. extractant and thioarsenous acid may molar of 2:1 Association. Simulation experiment based on alkali leaching solution, studied CO32- type TOMAC organic phase extraction thioarsenous acid the optimum conditions: organic phase composition, 30% TOMAC+15% 1-METHYLHEPTYL Alcohol + kerosene; aqueous feed solution composed of 0.5 mol/L Na OH+9.69 * 10-2 mol/L As III; extraction temperature, extraction at room temperature; compared to O/A=1/l. under the above conditions, AsIII single stage extraction rate of 85.3%. by the 4 stage countercurrent extraction raffinate As III concentration can be reduced to 1.34 * 10-3 mol/L, extraction the rate is over 98.5%, achieved the effective removal of arsenic alkaline solution. The loaded organic phase by 1 mol/L Na Cl+2.0 mol/L Na OH O/A=1/l mixed solution compared to single-stage stripping, stripping rate 89.8%. when stripping compared to 2/1, the 6 stage countercurrent stripping, the theory of the stripping rate can reach more than 98%. Further based on the infrared spectroscopy, analysis and comparison of the organic phase change structure transformation and counter extraction ".

【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X758

【参考文献】