反应萃取法提取赖氨酸的实验研究

以煤油稀释的二-（2-乙基己基）-磷（P204）作为萃取剂，对水溶液中的卜赖氨酸进行反应萃取。通过实验详细研究了搅拌速度、P2O4浓度、pH值及相比等因素对萃取率的影响。确定了萃取过程的适宜工艺条件：萃取时间大于25min、搅拌器转速为200rpm、有机相中P204与煤油的体积比为1、初始水相pH值在3—6之间、相比为1。用蒸馏水作溶剂可从萃取相中高效反萃。萃取及反萃取的理论级数分别为5级和4级。     

磷酸三丁酯和二异丙醚溶剂萃取 体系净化湿法磷酸的研究

以磷酸三丁酯（TBP）与二异丙醚为溶剂,采用溶剂萃取法净化湿法磷酸。研究了萃取剂中TBP体积分数、相比、萃取时间、搅拌转速、反萃取剂加入量对湿法磷酸净化效果的影响,确定了TBP与二异丙醚混合溶剂体系净化湿法磷酸的工艺条件。适宜工艺条件：萃取剂组成为TBP与二异丙醚体积比为1∶1,有机相与水相的体积比为 4∶1,萃取时间为25 min,搅拌转速为300 r/min,反萃取剂加入量为萃取相体积的20%。在此条件下,TBP与二异丙醚萃取体系对金属阳离子和氟离子有较好的分离能力。     

用磷酸三丁酯萃取分离硫酸铵母液中的HCN

研究了磷酸三丁酯(TBP)-磺化煤油体系从重庆某企业甘氨酸生产副产物硫酸铵母液中萃取分离HCN的工艺,考察了萃取体系、TBP体积分数、母液初始pH值、相比(Vorg∶Vaq)对萃取HCN的影响以及氢氧化钠浓度、相比(Vaq∶Vorg)和平衡pH值对HCN反萃的影响。结果表明:选用TBP作为萃取剂能够对硫酸铵母液中的HCN进行快速有效的萃取;TBP体积分数、母液初始pH值及相比对HCN萃取率影响显著;以含体积分数35%TBP的有机相作萃取剂,在相比(Vorg∶Vaq)为2∶1的条件下,pH值为2.92的含氰1.71 g/L的硫酸铵母液经3级错流萃取,萃余液中含氰低于0.5 mg/L,氰的萃取率接近100%;在相比(Vaq∶Vorg)为1∶1条件下,以0.6 mol/L的氢氧化钠为反萃液,控制反萃液平衡pH值大于13.0,氰的单级反萃率大于96%;含氰0.78 g/L的有机相在相比为1∶1条件下,经过2级错流反萃,氰基本上被反萃完全,贫有机相不经过处理可循环使用。     

溶剂萃取法分离油田卤水中的硼

以异辛醇为萃取剂,磺化煤油为稀释剂,从萃取剂体积分数、卤水pH值、相比、萃取时间、饱和萃取容量、反萃液pH值、反萃时间等方面考察了异辛醇对油田卤水中硼萃取的影响.结果表明:在卤水pH值为2、异辛醇体积分数为30％、相比(O/A)为1∶1、萃取时间为10 min时,通过4级萃取,硼的萃取率为95.3％;在相比为1∶l、反萃时间为10 min时用燕馏水3级反萃负载有机相,囊的反萃率达99％;整个过程穗的总回收率为94.3％.     

磷酸三丁酯和二异丙醚溶剂萃取体系脱除湿法磷酸中氟的研究

以磷酸三丁酯与二异丙醚为溶剂,采用溶剂萃取法脱除湿法磷酸中的氟。研究了萃取剂中TBP的体积分率、相比、萃取时间、搅拌转速、反萃剂加入量对氟的净化效果的影响,确定了磷酸三丁酯与二异丙醚混合溶剂体系脱氟的工艺条件。结果表明:萃取剂组成为TBP与二异丙醚体积比为1∶1;相比4∶1、萃取时间为5min、搅拌转速为300r/min、反萃剂加入量为萃取相体积的10%,在此条件下,磷酸三丁酯与二异丙醚萃取体系对氟离子有较好的分离能力。     

甲基异丁基酮净化湿法磷酸的研究

湿法磷酸含有较多杂质,通过净化可拓宽其用途。以甲基异丁基酮为溶剂,采用溶剂萃取法净化湿法磷酸。研究了相比、萃取时间、搅拌转速、反萃剂加入量对五氧化二磷分配系数、氟离子和硫酸根选择性的影响。实验结果表明：相比对五氧化二磷分配系数影响明显,但对硫酸根的选择性影响不明显;萃取时间、搅拌转速对五氧化二磷分配系数影响并不明显;甲基异丁基酮对氟离子和硫酸根均有良好的选择性。相比（有机相与水相的体积比）为4∶1、萃取时间为10 min、搅拌转速为200 r/min、反萃剂加入量为萃取后萃取剂体积的15%,净化效果较佳。     

P507与Cyanex272协同萃取分离溶液中钴镍离子

采用P507与Cyanex272协同萃取分离回收浸出液中的Ni2+, Co2+,考察了初始pH值、有机相复配比(P/C)和水油相比(A/O)的影响. 结果表明,协萃优化条件为：有机相皂化率50%,皂化时间30 min;有机相组成为10%复配萃取剂[P507:Cyanex272为3:2(j)]+85%磺化煤油+5% TBP;相比为3:1,水相pH值为2.5. 在此条件下,Co2+的一级萃取率为92.96%. 利用200 g/L硫酸反萃负载有机相,在相比2:3、振荡强度225 r/min、时间4 min的条件下,Co2+的反萃率为98.68%,实现了低pH值下Ni2+和Co2+的萃取分离.     

兰炭厂含酚废水的络合萃取研究

本文选用磷酸三丁酯(TBP)为萃取剂,煤油为稀释剂对高浓度含酚废水进行络合萃取,考察pH值、油/水相比(V/V)和TBP的含量(络合萃取剂中TBP的体积分数)等对酚萃取率的影响,并对酚进行反萃回收。实验结果表明:在pH值为6、温度为25℃、搅拌转速为625r·min-1、油/水相比为1∶3和TBP的含量为60%的最佳实验条件下,一级萃取率为94.7%,二级萃取率为98.12%,三级萃取率为99.5%。从经济效益考虑,选择一级萃取,其COD去除率为72.64%。用质量分数为10%的Na OH溶液作反萃取剂,反萃取温度为45℃,按油/碱比(V/V)为1∶1对一级萃取有机相进行两次反萃取,酚回收率可达97.24%。络合萃取剂在萃取-反萃取的过程中可多次循环使用。     

泡沫浮选萃取法分离精氨酸

以精氨酸水溶液为研究体系,采用十二烷基苯磺酸为起泡剂,以二(2-乙基已基)磷酸(P204)为萃取剂,对泡沫浮选萃取法分离提取水溶液中微量精氨酸的工艺进行了研究,考察了溶液中pH、鼓泡气体流量、表面活性剂浓度、萃取剂浓度的影响.结果表明在常温条件下,水相初始pH为7.0,萃取剂P204(稀释剂:正庚烷)体积分数为30%,水相和有机相的相比为17:1,十二烷基苯磺酸浓度为0.15 g/L,气体流量为200 mL/min时,溶液中精氨酸能达到满意的分离效果(富集比16.2,回收率97.2%).     

草酸强化三价铁离子的反萃性能

二(2-乙基己基)磷酸(P204)常作为溶液净化除铁的萃取剂，P204-磺化煤油体系中Fe³⁺与有机相形成络合能力较强的萃合物，使得Fe³⁺反萃比较困难，需采用较高浓度的酸作为反萃剂，但高浓度的酸会破坏有机分子的结构，影响萃取剂循环利用。针对P204-磺化煤油负铁有机相反萃困难的问题，提出利用草酸为反萃剂对负载1g/L铁的P204-磺化煤油有机相的反萃行为进行研究，考察了反萃转速、草酸浓度、反萃温度、反萃时间和相比对Fe³⁺反萃率的影响。结果表明：以反萃转速200r/min，草酸0.4mol/L，反萃时间10min，反萃温度40℃，反萃相比1∶1，采用二级逆流萃取方式，铁的反萃率可以达到99%以上；Fe³⁺反萃过程是吸热反应，其反应的焓变为81.58kJ/mol，反萃过程符合准一级反应动力学方程，对应活化能为49.5kJ/mol。进一步研究了反萃后P204-磺化煤油有机相对Fe³⁺的萃取性能。结果表明：经5次草酸反萃后的P204-磺化煤油有机相萃铁性能几乎不变，对比于高浓度的酸反萃，草酸反萃简化了反萃流程，降低了萃取剂的消耗。     

Liquid-Liquid Extraction of Uranium(VI) from Aqueous Solution using 1-Hydroxyalkylidene-1,1-diphosphonic Acids

The extraction of uranium(VI) from aqueous solutions has been investigated using 1-hydroxyhexadecylidene-1,1-diphosphonic acid (HHDPA) and 1-hydroxydodecylidene-1, 1-diphosphonic acid (HDDPA), which were synthesized and characterized by elemental analysis and by FT-IR, ¹H NMR, ³¹P NMR spectroscopy. In this article, we propose a tentative assignment for the shifts of those two ligands and their specific complexes with uranium(VI). We carried out the extraction of uranium(VI) by HHDPA and HDDPA from [carbon tetrachloride?+?2-octanol (v/v: 90%/10%)] solutions. Various factors such as contact time, pH, organic/aqueous phase ratio, and extractant concentration were considered. The optimum conditions obtained were: contact time?=?20 min, organic/aqueous phase ratio?=?1, pH value?=?3.0, and extractant concentration?=?0.3 M. The extraction yields are more significant in the case of the HHDPA which is equipped with a hydrocarbon chain, longer than that of the HDDPA. Logarithmic plots of the uranium(VI) distribution ratio vs. pH_eq and the extractant concentration showed that the ratio of extractant to extracted uranium(VI) (ligand/metal) is 2:1. The formula of the complex of uranium(VI) with the HHDPA and the DHDPA is UO₂(H₃L)₂ (HHDPA and DHDPA are denoted as H₄L). A spectroscopic analysis showed that coordination of uranium(VI) takes place via oxygen atoms.     

Extraction of vanadium(V) from sulfate solutions by ACORGA M5640

ACORGA M5640 (hydroxy‐oxime derivative) has been applied as an extraction reagent for vanadium(V) from sulfate media. The extraction system was studied as a function of contact time, temperature, aqueous pH, diluent of the organic phase, and metal and extractant concentrations. The extraction reaction is endothermic and it is dependent on the organic diluent, aqueous pH and extractant concentration. The data have been analysed numerically to determine the stoichiometry of extracted species and their equilibrium constants. It was found that vanadium was extracted into the organic phase by a complex mechanism which involves the formation of two species (VO₂R and VO₂R. HR, where R represents the extractant). Vanadium stripping by acidic and ammonium hydroxide solutions was also studied. Copyright © 2003 Society of Chemical Industry     

Solvent extraction of gold by LIX 79: experimental equilibrium study

The extraction of gold(I) from aurocyanide aqueous solutions using LIX 79 has been studied. Different variables that could affect the extraction system were evaluated: equilibration time, aqueous pH, metal and extractant concentrations, organic phase diluent and aqueous ionic strength. The extraction of the aurocyanide complex with respect to other metal‐cyano complexes has also been studied on both synthetic and real leach solutions. Gold experimental data have been analysed numerically to determine the stoichiometry of extracted species and its equilibrium constant. It was found that gold(I) was extracted into the organic phase by the formation of the species RHAu(CN)₂ (LIX 79=R). Stripping of gold from loaded organic phases was carried out using NaOH or NaCN solutions. © 1999 Society of Chemical Industry     

Silver electrowinning from silver(I)–calixarene complexes by two-phase electrolysis

Results are reported, providing the basis for an elegant new process for metal recovery from acidic solutions, by integrating solvent extraction (SX) and electrowinning (EW) in a single process, rather than operating them separately, as in conventional SX–EW processes. Calixarene-tetramide and its thio-analogue were used for the extraction of silver(I) ions from aqueous phases into dichloromethane, both compounds achieving extraction efficiencies >90%. The effects were determined of extractant and silver(I) concentrations, aqueous phase pH, and the presence of sodium ions, on the distribution of Ag(I) between aqueous and organic phases. Due to the impossibility of stripping the extracted metal conventionally, electro-reductive stripping of silver(I) from the loaded organic phase was carried out in the calixarene/nitric acid two-phase system. The effects were also investigated of current density or electrode potential on silver deposition current efficiencies and cell voltages. Based on experimental data, a new process for silver(I) removal from very dilute solutions was proposed that showed high percentage extractions of silver(I) from the aqueous phase, coupled to direct EW of silver from the calixarene complex in the loaded organic phase, regenerating the extractant for recycle. Current efficiencies in the range from 60% to 90% and cell voltages <3.5 V were achieved simultaneously in this process.     

Synergistic Extraction of Gallium from Sulfate Solution

A novel extractant mixture, di-2-ethylhexyl phosphate (DEHPA) plus HX, was proposed and tested for recovering gallium from sulfate solution. It was found that the extraction capacity of DEPHA for gallium from sulfate solution could be enhanced significantly due to the synergistic effect of acidic extractant HX. Gallium extraction is negligible below pH 0 and highly sensitive to pH of aqueous phase in the range from 0 to 1, and satisfactory extraction can be gained at pH>1. More than 96% Ga extraction was obtained using 15% DEHPA plus 2% HX. Although Fe (Ⅲ) was found to be extracted preferentially to Ga (Ⅲ), effective extraction of Ga (Ⅲ) was possible by reducing ferric to the ferrous state prior to extraction. A loaded organic phase containing 0.48g L-1 Ga could be produced from solution of 0.12g L-1 Ga at A/O ratio of 4 : 1 via three mixer-settler operation stages. Gallium was stripped quantitatively from the loaded organic phase with l,5mol L-1 of sulfuric acid.     

硫酸体系中P507对铟锌锰的萃取分离研究

根据软锰矿和闪锌矿在酸性条件下同槽浸出所得浸出液特点(含铟、锌、锰离子),用P507萃取浸出液中的铟,分离出锌和锰。考察了平衡水相酸度(氢离子浓度)、萃取剂体积分数、萃取温度、有机相与水相体积比、萃取时间等因素对铟萃取率的影响。研究结果表明:在室温下,在平衡水相酸度为2.5 mol/L、P507体积分数为30%(30%P507+70%磺化煤油)、有机相与水相体积比为1∶1、萃取时间为10 min条件下,铟的一级萃取率在99%以上,锌和锰一级萃取率在1.20%以下,铟与锌和锰的分离达到最佳效果;负载有机相经水洗,锌和锰洗涤率为99%,铟洗涤率为0;用2.0 mol/L盐酸进行反萃,铟反萃率在98%以上,达到了富集铟分离锌和锰的目的。     

Solvent extraction of silver by LIX® 79: experimental equilibrium study

The extraction of silver(I) from argentocyanide aqueous cyanide solutions using LIX^® 79 has been studied. Different variables that could affect the extraction system were evaluated: equilibration time, aqueous pH, metal and extractant concentrations, and organic phase diluent. The extraction of the Ag(CN)₂^? complex with respect to other metal‐cyano complexes has also been studied on both synthetic and real leach solutions. Experimental data relating to silver have been analysed numerically to determine the stoichiometry of the extracted species and its equilibrium constant. It was found that silver(I) was extracted into the organic phase by the formation of the species RHAg(CN)₂ (LIX 79 = R). Copyright © 2004 Society of Chemical Industry     

溶剂萃取法从提锂后盐湖卤水中提硼的工艺研究

以青海东台吉乃尔盐湖提锂后卤水为原料,用2-乙基-1,3-己二醇分别与异辛醇、异戊醇组合的混合醇从卤水中萃取硼,从萃取剂体积分数、酸度、相比、萃取时间、萃取温度、饱和萃取容量、反萃剂浓度、反萃时间等方面加以实验,获得了混合醇从卤水中萃取提硼的最佳工艺条件:萃取剂体积分数30% ,水相pH为3,相比1:1,萃取时间10 min,最大饱和容量61.4 g/L(B2O3).并与一元醇进行了比较,得出混合醇的萃取效果远好于一元醇.     

Extraction of molybdenum(VI) from sulfate solutions by LIX 622

The application of LIX 622 (oxime derivative) as an extraction reagent of molybdenum (VI) from sulfate media was studied. The extraction system was studied as a function of contact time, temperature, aqueous pH, diluent of the organic phase and metal and extractant concentrations. The extraction is exothermic and it is dependent on the organic diluent, aqueous pH and reagent concentration. The data have been analysed numerically to determine the stoichiometry of extracted species and their equilibrium constants. It was found that molybdenum was extracted into the organic phase by a complex mechanism which involves the formation of three species (MoO₂L₂, MoO₄H₃HL⁺HSO₄⁻ and MoO₄H₂HL, where L represents the extractant). Molybdenum stripping by acidic and ammonium hydroxide solutions was also studied. © 2000 Society of Chemical Industry