EDTA辅助离子液体Aliquat 336萃取废水中Cu(Ⅱ)的研究

研究了络合剂EDTA辅助室温疏水性离子液体Aliquat 336(三辛基甲基氯化铵)对模拟废水中Cu(Ⅱ)的萃取性能。结果表明,当Aliquat 336与水溶液的体积比(VILs∶Vaq)为1∶5,Cu(Ⅱ)初始质量浓度为600 mg/L,pH值为4时,加入等浓度的EDTA可以使水中Cu(Ⅱ)的萃取率从未用EDTA时的5.0%提高到88.7%,说明络合剂EDTA的存在能够显著提高Aliquat 336对模拟废水中Cu(Ⅱ)的萃取率。最优萃取条件为:EDTA与Cu(Ⅱ)的浓度比为1.0,VILs∶Vaq为1∶5,pH值为4,温度为25℃,该条件下废水中Cu(Ⅱ)的去除率达到88.7%。Aliquat 336可多次循环回用,循环回用4次后其萃取率仍可达80%以上。     

典型有机磷类萃取剂在溶剂萃取中协同萃取的研究进展

协同萃取作为溶剂萃取法的分支被广泛研究.对于协同萃取的机理探索,必须阐明协同效应产生的微观原因,并给出微观与宏观性质的联系,因此从分子的微观结构和内部运动认识协同萃取以及影响因素尤为重要.本工作重点综述了萃取剂之间、萃取剂与金属离子之间的协同作用机理以及影响其作用因素的研究进展,指出协同萃取的本质是氢键的形成导致萃取剂...     

水-醋酸-醋酸正丁酯三元体系液液平衡研究

文章用液液平衡装置在常压下,测定了水．醋酸-醋酸正丁酯三元体系40℃的液液相平衡数据。运用Othmer-Tobias方法对系线组成进行关联。由实验数据回归确定了NRTL、UNIQUAC以及修正的UNIFAC活度系数模型参数,并运用这些模型对体系相平衡进行了预测。将实验数据与关联结果比较,结果表明,三种方程均能较好地对溶液组成进行预测,其中UNIQUAC方程的拟合精度最好。     

萃取-蒸馏法处理与回收糠醛废水中醋酸的研究

本文研究了溶剂萃取法去除糠醛废水中醋酸的工艺过程。通过实验得出，用含磷溶剂和烷烃化合物组成的混合溶剂处理糠醛废水中，醋酸的回收率较高。含醋酸的溶剂可以通过蒸馏回收醋酸，回收的溶剂可以循环使用，经处理过的废水可以利用，从而达到不排放或少排放的闭路循环。     

季铵盐(Aliquat 336)萃取对氨基苯磺酸的特性研究

利用季铵盐(Aliquat 336)为反应剂,在较宽的pH值条件下,研究了对氨基苯磺酸稀溶液的萃取相平衡特性;测定了反应剂浓度、稀释剂种类、盐的存在以及溶液pH值对反应萃取平衡分配系数的影响;提出了反应剂与对氨基苯磺酸负离子的阴离子交换反应机理,建立了平衡分配系数D值的表达式。结果表明,极性稀释剂不利于对氨基苯磺酸的萃取,惰性稀释剂能提供较大的萃取平衡分配系数,其顺序为:苯>四氯化碳>氯仿>正辛醇;盐的存在会降低Aliquat 336的萃取效率;与三烷基胺(Alamine 336)相比,Aliquat 336具有更宽的pH值适用范围。     

用化学理论关联醋酸-水体系汽液平衡

在对苯二甲酸及间苯二甲酸的生产过程中涉及醋酸溶液的闪蒸和精馏操作,通过计算准确地给出醋酸-水体系的汽液平衡数据对工艺控制和优化显得十分重要。从分子缔合的化学理论模型出发,结合S-H模型系统地计算了强缔合性流体混合物(醋酸-水体系)的汽液平衡。对常压和高压下醋酸-水体系汽液平衡的关联误差小于5%。     

含离子液体醋酸-醋酸正丙酯物系等压汽液平衡

用Ellis双循环汽液平衡釜测定在常压下2种醋酸正丙酯-醋酸-离子液体的等压汽液平衡数据,即醋酸正丙酯-醋酸-三丁基铵醋酸盐([N4,4,4,H][AC])和醋酸正丙酯-醋酸-三辛基铵醋酸盐([N8,8,8,H][AC])。实验结果表明:当加入[N4,4,4,H][AC]和[N8,8,8,H][AC]后,醋酸正丙酯-醋酸二组分物系的汽液平衡线发生了偏离,[N4,4,4,H][AC]和[N8,8,8,H][AC]表现出盐效应,醋酸正丙酯对醋酸的相对挥发度发生改变。离子液体对醋酸正丙酯-醋酸的盐效应顺序为:[N4,4,4,H][AC][N8,8,8,H][AC]。因此,[N4,4,4,H][AC]和[N8,8,8,H][AC]可以作为醋酸正丙酯-醋酸物系萃取精馏的溶剂,汽液平衡数据的测定可为分离过程优化设计提供依据。     

三正丁胺络合萃取精馏分离醋酸和水

A new separation method, reactive extractive distillation, was put forward for separating water and acetic acid. The separation mechanism was analyzed through infrared spectra technique. Isobaric vapor-liquid equilibrium (VLE) data at 101.33 kPa for the binary or ternary systems consisting of water, acetic acid and tributylamine were measured. The activity coefficients were correlated by using Wilson, NRTL, and UNIQUAC Equations.The VLE experiment showed that tributylamine could enhance the relative volatility of water to acetic acid. An extractive distillation experiment was carried out and proved that tributylamine was a good extractive solvent.     

醋酸+二甲基亚砜等压汽液平衡研究

二甲基亚砜可作为水+醋酸体系的萃取共沸剂,文中用改进的Rose汽液平衡釜,测定101.33 kPa下醋酸+二甲基亚砜二元体系的等压汽液平衡数据,实验数据通过了热力学一致性逐点校验。考虑醋酸在汽相中的缔合效应和非理想性,分别采用van Laar,Wilson和NRTL模型对醋酸+二甲基亚砜体系的汽液平衡数据进行关联,得到了相应的模型参数和关联偏差。结果表明,NRTL模型关联结果较好,温度平均绝对偏差0.26 K,醋酸在汽相中的平均绝对偏差为0.002 7,可为醋酸萃取精馏工艺设计提供必要的基础数据。     

三辛胺萃取分离乳酸-醋酸

选择三辛胺为络合剂、正辛醇为稀释剂、乳酸和醋酸为被萃溶质 ,系统地研究了水相pH值及络合剂含量对单组分乳酸、醋酸及其混合物萃取特性的影响。在适当假设条件的基础上 ,建立了考虑络合萃取及物理萃取的单组分及双组分体系的相平衡分配系数表达式。在本文的实验条件下 ,随络合剂含量的升高 ,乳酸、醋酸的单组分及其混合物中各组分相平衡分配系数皆升高 ,分离因子 β增大 ;随水相平衡pH值的升高 ,相平衡分配系数均降低 ,分离因子也呈下降的趋势 .采用本文的模型进行模型参数拟合 ,其精度较好。利用单组分的络合反应平衡常数可成功地预测双组分体系中各组分的相平衡分配系数值     

Extraction of protactinium from acid media using Aliquat 336

Solvent extraction studies on protactinium were carried out from hydrofluoric acid, hydrochloric acid, and a mixture of hydrochloric and hydrofluoric acids using Aliquat 336 and ²³¹Pa. The extraction of protactinium from hydrofluoric acid (0.025–10 M) decreased with increasing acid concentration and was less than 10% above 5 M. The extraction from hydrochloric acid (0.5–8 M) started only above 4 M and increased with increasing acid concentration. The extraction of protactinium from a mixture containing hydrochloric acid (0.5–8 M) and 0.03 M hydrofluoric acid decreased with increasing acid concentration reached to a minimum at about 2 M and then increased with increasing acid concentration. At low acidity, extraction of protactinium from hydrofluoric acid was higher compared to hydrochloric acid and the mixture of hydrochloric and hydrofluoric acids. Nitric acid (10 M) and hydrofluoric acid (10 M) were suitable for quantitative recovery of protactinium from organic phase. The extraction of ²³¹Pa from real thorium lean raffinate of thorium–uranium extraction process was studied using optimized extraction conditions.     

醋酸甲酯-甲醇-水-醋酸四元反应体系汽液平衡

用改进的Rose Williams平衡釜测定了恒压(0.1013MPa)下醋酸甲酯-甲醇-水-醋酸四元反应体系汽液平衡数据。分别用Wilson、NRTL和UNIQUAC3个方程计算液相的活度系数。对含缔合组分的汽相用“化学理论”修正其非理想性,预测了该四元反应体系的反应相平衡数据,并与实测值比较,其拟合结果令人满意。     

EXTRACTION OF TITANIUM(IV) FROM AQUEOUS HYDROCHLORIC ACID SOLUTIONS INTO ALAMINE 336-M-XYLENE MIXTURES

Extraction of Ti(IV) from its aqueous hydrochloric acid solutions into organic Alamine 336-m-xylene systems was investigated. Extraction experiments were conducted with three different initial metal concentrations of 1, 3, and 6 mg/mL, each at three acidic molarities of 1, 5, and 10 M. It was observed that the extractability of Ti(IV) increases with increasing acidic molarities. Alamine 336 diluted with m-xylene was found to be a suitable extractant for Ti(IV) across this acidic range. In parallel, a mathematical model was developed to correlate metal extractability and Alamine 336 volume content. Optimal Alamine 336 contents were estimated for single-stage extraction.     

EXTRACTION OF TITANIUM(IV) FROM AQUEOUS HYDROCHLORIC ACID SOLUTIONS INTO ALAMINE 336-M-XYLENE MIXTURES

Extraction of Ti(IV) from its aqueous hydrochloric acid solutions into organic Alamine 336-m-xylene systems was investigated. Extraction experiments were conducted with three different initial metal concentrations of 1, 3, and 6 mg/mL, each at three acidic molarities of 1, 5, and 10 M. It was observed that the extractability of Ti(IV) increases with increasing acidic molarities. Alamine 336 diluted with m-xylene was found to be a suitable extractant for Ti(IV) across this acidic range. In parallel, a mathematical model was developed to correlate metal extractability and Alamine 336 volume content. Optimal Alamine 336 contents were estimated for single-stage extraction.     

乙二醛溶液体系中乙酸络合萃取的动力学研究

采用恒界面池法研究了乙酸在乙二醛溶液中的萃取动力学,实验结果表明：萃取速率由界面化学反应所控制,且表观反应速率方程为：ｒ＝ｋｓＣＨＡｃ１．３６４１,在２５℃时的反应速率常数ｋｓ＝１．８２×１０－２ｍｏｌ／ｃｍ２·ｓ。此外,还研究了温度对反应速率的影响,求取了表观反应的活化能Ｅａ＝２３．２８３３ｋＪ／ｍｏｌ,从而进一步说明了萃取速率控制步骤为界面化学反应所控制。