苯酚羟化液多级萃取分离及磷酸三丁酯配合萃取过程

针对甲基异丁基甲酮(MIBK)和异丙醚(DIPE)两种萃取剂以及在不同剂溶比时萃取苯酚羟化液的萃取效果进行了比较;并进一步采用磷酸三丁酯(TBP)为配合剂、甲基异丁基甲酮(MIBK)为稀释剂研究了苯酚羟化液的配合萃取.结果表明:MIBK的萃取效果优于DIPE,MIBK为萃取剂时的最优剂溶比为1:3,此时苯酚羟化液的三级错流萃取率可达99%发上.通过MIBK对羟化液的多级错流萃取过程模拟计算进一步验证了此结论.采用TBP络合萃取苯酚羟化液,实验表明,萃取率可达到99.76%.     

萃取置换法回收处理氟苯生产废水中的苯酚

以磷酸三丁酯(TBP)为萃取剂、NaOH水溶液为反萃剂,采用萃取置换法回收处理氟苯生产废水中的苯酚.研究了萃取剂浓度、萃取时间、pH值及相比对萃取率的影响和相比、反萃时间及NaOH溶液浓度对反萃率的影响.经3级萃取和2级反萃取,苯酚的回收率达98%,废水中苯酚含量可降至19.7 mg/L.萃取置换法操作简单,费用低廉,易于工业化.     

萃取置换法预处理氟苯生产废水的实验研究

以磷酸三丁酯(TBP)为萃取剂、NaOH水溶液为反萃剂,采用萃取置换法回收处理氟苯生产废水中的苯酚。研究了萃取剂浓度、萃取时间、pH值及相比对萃取率的影响和相比、反萃时间及NaOH溶液浓度对反萃率的影响。经3级萃取和2级反萃,苯酚的回收率达98%,废水中苯酚含量可降至19.7 mg/L。萃取置换法操作简单,费用低廉,易于工业化。     

撞击流旋转填料床内磷酸三丁酯对苯酚的络合萃取

在撞击流-旋转填料床(IS—RPB)内进行了磷酸三丁酯(TBP)对苯酚稀溶液的络合萃取实验研究。在研究IS—RPB转速和撞击流初速对萃取级效率影响的基础上,确定了最适宜操作条件。在最适宜操作条件下,应用不同体积组成的TBP 煤油萃取剂对苯酚稀溶液进行萃取,得到了95％以上的除酚率。动力学分析表明,TBP与苯酚的络合反应是一个快速过程,IS—RPB作为萃取器使用可以对扩散类型的萃取过程提供很高的萃取级效率。     

磷酸三丁酯/煤油支撑液膜体系中苯酚的传质分离

研究了苯酚在以多孔聚丙烯平板膜(Celgard2500)为支撑体、磷酸三丁酯(TBP)为膜载体和煤油为膜溶剂的支撑液膜体系中的传质过程;用传统萃取法测定了TBP/煤油体系中苯酚络合物摩尔比为1∶1,同时得到25.0℃萃取平衡常数为96.72;考察了原料相pH值、初始质量浓度、膜二侧转速、载体浓度和反萃取相碱浓度对苯酚传质的影响,确定了该体系分离苯酚的最佳条件:原料相pH<9,苯酚初始质量浓度<1 000 mg/L,膜二侧转速>300 r/m in,载体浓度为0.55 mol/L,反萃取相碱浓度0.10 mol/L;根据双膜理论提出苯酚的传质动力学方程,采用直线斜率法计算了苯酚在TBP/煤油支撑液膜体系中的扩散层厚度和膜内扩散系数,计算结果表明动力学方程计算值能较好地与实验值吻合,平均相对误差在2%以内。     

邻、对苯二酚热敏性研究及产品分离工艺优化

针对苯酚羟基化反应产物(羟化液)中水含量高,直接蒸馏脱水能耗高和物料热敏损失大的问题,对二元酚的热敏性进行了实验研究,并用异丙醚做萃取溶剂对模拟羟化液组成的含酚水溶液进行了萃取可行性实验研究,拟应用高效萃取技术完成脱水过程对分离工艺进行优化。     

溶剂萃取法处理苯酚稀溶液及其废水的研究

为探索工业含酚废水处理的适宜萃取剂,选用具有物理萃取和络合萃取作用的两类萃取剂正辛醇、甲基异丁基甲酮(MIBK)和磷酸三丁酯(TBP)(以煤油为稀释剂)进行了苯酚稀溶液萃取性能的实验研究。测定了不同溶液pH值、初始苯酚浓度和TBP浓度条件下的萃取平衡数据,分析了各萃取剂萃取平衡的规律及机理。结果表明,虽然各萃取剂的萃取机理不同,但在酸性和中性范围内都可获得较大的萃取平衡分配系数,所以,这三种萃取剂的适宜pH值操作条件为酸性和中性,且在稀溶液的范围内溶剂的萃取能力为TBP > MIBK >正辛醇,而在极稀的苯酚浓度条件下(<20mgL-1),则为正辛醇> TBP > MIBK。同时,正辛醇、TBP处理工业含酚废水的错流萃取实验表明,若考虑通过单一的萃取方法使得废水中苯酚的浓度达到国家排放标准(0.5mgL-1),正辛醇为适宜的萃取剂。     

基于磷酸三丁酯络合萃取法的脱酚机理研究

从微观层面的角度,对磷酸三丁酯(TBP)络合萃取脱酚过程的机理进行研究,首先采用红外光谱分析手段,分别测定TBP负载苯酚及邻苯二酚的红外光谱图,通过相应官能团的波数位移变化,得出TBP与酚类物质属氢键缔合;其次以TBP作为络合剂,煤油作为稀释剂,对苯酚的模拟水样进行萃取,研究络合萃取过程中的络合物结构,并建立络合萃取平衡模型,从而对络合萃取过程中分配系数进行预测。研究结果表明,磷酸三丁酯萃取苯酚的平衡分配系数模型对实验数据具有较好的拟合度。     

[Bmim]PF6-TBP萃取剂微萃取富集水中苯酚

将常规离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6)与特定萃取剂磷酸三丁酯(TBP)结合,建立了超声辅助的微萃取富集目标物苯酚的方法,研究了萃取剂种类、用量、pH值、超声水浴温度及离子强度等因素对富集效果的影响,得到微萃取的最佳实验条件,对该方法的富集机理进行了探讨. 结果表明,在较少的萃取剂用量(30 mL [Bmim]PF6-30 mL TBP)、较低的水浴温度(273.15 K)及无盐效应和pH值影响的条件下,富集倍数最佳达128. 二元萃取剂对苯酚的高效富集,主要是由于TBP中P==O键与苯酚?OH中的?H缔合,形成配合物.     

磷酸三丁酯萃取分离钛铁矿亚熔盐反应产物酸解液中Fe3+及金红石型TiO2的制备

在盐酸介质中以磷酸三丁酯(TBP)为萃取剂、磺化煤油为稀释剂,从钛铁矿与氢氧化钾亚熔盐反应产物的酸解液中萃取分离Fe3+,并利用萃取后的含钛液水解制备二氧化钛. 考察了萃取剂浓度、盐酸浓度、有机相和水相体积比(O/A)和萃取时间对铁萃取率的影响. 结果表明,钾系亚熔盐法分解钛铁矿的分解率在96%以上. 萃取率随着TBP浓度及盐酸浓度的增加和O/A值的减小而增大;通过调节萃取条件,萃取率可以达到99%以上. 用1.0 mol/L的NaCl溶液进行反萃,反萃率可达98%以上. 萃取后含钛液经水解可以制得纯度高于98%的金红石型TiO2球状颗粒.     

磷酸三丁酯络合萃取对氨基酚的研究

采用磷酸三丁酯(TBP)络合萃取对氨基酚(PAP)废水,讨论了溶液平衡pH值、稀释剂种类以及温度对萃取效果的影响。根据C lausius-C lapyron方程测得萃取反应热ΔH=-3.47 kJ/mol,采用双对数坐标法推测了萃合物组成为TBP与PAP以1∶1形式络合,并观察负载有机相红外光谱确定了络合反应机理为TBP的磷酰基与PAP的羟基之间发生氢键缔合。对实际废水进行三级错流萃取,对氨基酚的去除率达到97.5%。     

乳化萃取在湿法磷酸净化过程中的应用

乳化萃取是一种新型的萃取分离技术。实验选用磷酸三丁酯为萃取剂,煤油为稀释剂,采用乳化萃取技术对湿法磷酸净化进行研究,考察了搅拌时间和搅拌转速对乳状液液滴直径及P2O5萃取率的影响。结果表明:该萃取体系下乳状液的类型为W/O型,当搅拌转速为500r/min,搅拌时间为30s时,萃取达到平衡,一级P2O5萃取率为45%,而常规萃取则要1h才能达到平衡。     

络合萃取法在2-萘酚废水处理中的应用研究

采用络合萃取法,以三烷基胺和磷酸三丁酯为萃取剂、煤油为稀释剂处理2-萘酚β-盐母液废水。试验结果表明：采用20％三烷基胺-20％磷酸三丁酯-60％煤油的混合型络合萃取剂对2．萘酚废水进行萃取具有较高的COD脱除率。     

磷酸三丁酯络合萃取丁酸的研究

用络合萃取法分离极性有机稀溶液 ,具有高效性和高选择性。利用磷酸三丁酯 (TBP)为络合剂 ,分别采用甲苯、异丙基甲酮、正辛醇、煤油作为稀释剂萃取丁酸稀溶液 ,系统研究了不同稀释剂对络合萃取平衡的影响 ,最终从效能、毒性、价格等综合因素考虑 ,选用正辛醇作为稀释剂 ;分析了络合剂浓度、丁酸溶液初始浓度、溶液 pH值以及温度对络合萃取相平衡分配系数的影响 ;利用红外光谱测定了负载有机相中萃合物的结构 ;并进行了有机溶剂的再生研究     

Extraction of penicillin G from aqueous solutions: Analysis of reaction equilibrium and mass transfer

Analysis of the reaction equilibrium and mass transfer in the extraction of penicillin G (Pen G) into an organic phase is an important research area to develop a cost-effective process for its separation from an aqueous fermentation media. In order to evaluate this, equilibrium experiments were first carried out to select the organic phase (composed of the carrier and solvent) that gives good values for the distribution of penicillin G between the aqueous and organic phases. An organic phase of Amberlite LA-2 in any of the solvents (Shellsol TK/butyl acetate/tributyl phosphate) gave high distribution coefficient and the stoichiometry of the reaction has been shown to follow a simple ratio of 2:2. The performance of the organic phases was evaluated in a membrane contactor and very high percentage extraction was achieved. The extraction was performed by contacting a “feed” solution containing penicillin G (flowing in the fiber side) with an “organic phase” of Amberlite LA-2 in one of the solvents (flowing on the shell side) of the contactor. The antibiotic solutes formed complex with the Amberlite LA-2 molecules which were transported across the fiber wall to the shell side and extracted in the organic phase. The extraction in once-through mode was low and the feed/organic solutions need to be recycled to increase the percentage extraction. In the recycle mode operated at flow rates of 3.6–4.4 mL/s, an extraction of 90–98% was achieved. A simple mathematical model and its semi-analytical solution presented here can be used to determine the overall mass transfer coefficient using the experimental values of the distribution coefficient, operating parameters and the dimensions of the membrane module.     

URANIUM EXTRACTION SELECTIVITIES OF DIBUTYL CARBITOL AND TRIBUTYL PHOSPHATE IN THE SYSTEM UO2(NO3)2-HNO3H2O-Al(NO3)3-SOLVENT

ABSTRACT

Historically, both the BUTEX (dibutyl carbitol-based) and PUREX (tributyl phosphate-based) processes have been used for uranium recovery and purification. Currently, BUTEX- and PUREX-type extraction processes are being used in series for recovery of isotopically enriched uranium at the Oak Ridge Y-12 Plant. The use of two solvents is predicated on the differing selectivities of each with regard to the contaminant elements present in the uranium source stream. As part of efforts to streamline plant operations in response to decreasing throughput requirements, the Y-12 Development Division is evaluating options for converting the existing two-solvent operation to a single-solvent process.

At the request of the Y-12 Development Division, the Robotics and Process Division at the Oak Ridge National Laboratory has undertaken evaluation of solvents for use in a single-solvent recovery process. Initial efforts have been directed toward development of a single-solvent, dibutyl carbitol-or tributyl phosphate-based process that produces a product with purity equal to or exceeding what is currently obtained in the two-cycle, two-solvent operation. The test effort has involved both laboratory equilibrium determinations and engineering-scale process demonstrations in multistage flowsheets using centrifugal solvent extraction contactors. Excellent uranium recovery results have been obtained from both dibutyl carbitol- and tributyl phosphate-based solvent extraction flowsheets. Contaminant rejection performance by the two solvents is similar for many of the elements considered. Extraction of some contaminant elements by tributyl phosphate is significant enough to conclude that the solvent is not as selective for uranium as is dibutyl carbitol. This determination does not necessarily eliminate tributyl phosphate from consideration for use in a single-solvent process but does indicate a need for effective scrubbing of contaminants from uranium-loaded tributyl phosphate, possibly by partial reflux of the purified, aqueous uranyl nitrate product solution.

     

The hydrochloric acid route for phosphate rock

When phosphate rock is leached with hydrochloric acid, radium can be removed by co-precipitation with Ba_0.4Ca_0.6SO₄ and uranium by extraction with a 5% solution of tributyl phosphate in hexane or Varsol. Phosphoric acid is then separated from calcium chloride solution and other impurities by extraction with undiluted tributyl phosphate. The lanthanides can be precipitated from the raffinate by NH₃, and CaSO₄.2H₂O by H₂SO₄ to regenerate HCl for recycle. The organic phase containing H₃PO₄ can be stripped by NH₃ to yield ammonium phosphate and to regenerate the tributyl phosphate for recycle. Fluorine can be precipitated from the initial leach solution as Na₂SiF₆.     

湿法磷酸溶剂萃取法工艺的研究

研究了溶剂萃取法净化湿法磷酸的工艺。试验结果表明,以异丙醚和磷酸三丁酯作为萃取剂对用硫酸分解磷矿制得的浓缩磷酸进行了多级逆流萃取及反萃取,可以得到高浓度净化磷酸。该工艺具有较好的经济效益,为湿法磷酸的净化提供了一条较好的途径。     

磷酸三丁酯络合萃取含酚废水的应用研究

利用磷酸三丁酯、三烷基胺为络合剂,分别采用苯、甲苯、正辛醇、煤油作为稀释剂对含酚废水进行络合萃取.实验结果表明,采用磷酸三丁酯一甲苯混合溶剂对含酚废水进行萃取具有相当高的分配系数;同时探讨了络合萃取技术处理含酚废水工业化的可行性,实验结果表明具有工业化应用前景.