稀土和铝在皂化氯代环烷酸体系中分配比及分离系数的研究

分别对萃取剂皂化值为0.35mol/L、0.40mol/L,不同料液酸度、铝浓度条件下氯化稀土溶液在皂化氯代环烷酸萃取体系中的稀土和铝分配比及分离系数进行研究,表明当料液中含有中、高浓度铝时,皂化值为0.35mol/L氯化环烷酸体系可以在较高酸度的条件下获得铝和稀土相对更高的分离系数及更好的分离效果.实际生产中可通过提高料液酸度实现铝和稀土的有效分离,同时抑制其它非稀土杂质的萃取,更有利于降低产品中杂质的含量.     

氯代环烷酸体系萃取单一稀土和铝分配比及分离系数的研究

通过对不同萃取剂皂化值、料液酸度和铝浓度条件下,单一稀土和铝在氯代环烷酸体系中的分配比及分离系数的研究分析,阐明了当料液的酸度较高时,皂化值为0.35 mol.L-1氯化环烷酸体系可以获得铝和稀土相对更高的分离系数及更好的分离效果。pH值为0.20左右,对于中、高浓度铝的料液基本都能取得较好的稀土和铝分离效果;pH值为0.10左右,对于低浓度铝的料液基本都能取得较好的稀土和铝分离效果。实际生产中可通过提高料液酸度实现铝和稀土的有效分离,同时抑制其他非稀土杂质的萃取,更有利于降低产品中杂质的含量。     

氯代环烷酸萃取体系中稀土和铝分配比及分离因数的研究

研究萃取剂皂化值、料液酸度和铝浓度对稀土和铝在氯代环烷酸体系中的分配比和分离因数的影响。结果表明,当料液的铝浓度较高时,该萃取体系在较高料液酸度下仍可较好地分离稀土和铝,且未有乳化现象发生;采用氯代环烷酸萃取体系分离稀土和铝的优化条件为:萃取剂皂化值0.35 mol/L、铝浓度12.5 mmol/L、pH=0.10,此条件下分配比DAl=0.53,DRE=0.05,分离因数βAl/RE=10.6。     

混合稀土料液中环烷酸萃取分离稀土和铝的研究

在环烷酸体系中,对不同混合轻稀土料液酸度、铝浓度和萃取剂皂化值条件下,一定配比混合稀土和铝的分配比D、分离系数β进行研究。结果表明,混合稀土料液酸度pH=0.5时,D_(Al)=16,D_(RE)=0.044 8,β_(Al)/_(RE)=356.9;当料液中Al_2O_3浓度为0.17～0.32g/L时,氧化铝的分配比D_(Al)1,β_(Al)/_(RE)有较大值;皂化度为0.3mol/L时,不仅能够避免由过皂化引起的乳化发生,同时稀土和铝还有较好的分离效果。因此高酸度、低浓度铝和低皂化度的环烷酸体系可以获得铝和混合稀土更好的分离效果和较高的分离系数。在最优工艺条件下进行稀土和铝分离萃取试验,有机相和水相较易分层,萃取反应界面基本无三相,分相极为理想,余液中铝含量小于0.011%,满足工业生产对铝含量的要求。     

环烷酸体系萃取分离稀土和铝的实验研究

在不改变料液酸度的条件下,研究了不同皂化值、相比和萃取级数对稀土和铝在环烷酸体系中的分配比和分离系数的影响.实验结果表明,环烷酸萃取体系分离稀土和铝的较优工艺参数为：皂化值0.25 mol/L、相比O/A=1.5,在此条件下,分配比DAl=4.035,DRE=0.111,分离系数βAl/RE=36.35,此外,随着萃取级数的增加,除铝率也会增加,当萃取级数大于2时,除铝率可达95%以上.     

环烷酸萃取分离稀土料液中铝的研究

采用环烷酸-异辛醇-煤油体系,研究去除高浓度稀土料液中铝离子杂质的最佳工艺条件。通过改变有机相皂化度、相比(O/A)等条件,对铝含量高达1.16mg/mL的稀土料液进行除杂试验。经过反复实验,最终确定环烷酸萃取分离稀土料液中铝离子的最佳工艺条件为:环烷酸/异辛醇/煤油=1∶1∶3体积比、皂化度0.10以及相比(O/A)=1.5/1。     

高浓度镨钕料液去除杂质铝的工艺研究(Ⅰ)

以混合型稀土矿制得的镨钕料液为研究对象,采用环烷酸-异辛醇-磺化煤油作为萃取有机体系,萃取分离高浓度镨钕料液中的非稀土杂质铝,考察了萃取过程中环烷酸浓度、有机皂化度、相比、萃取温度等条件对铝去除率、稀土损失率以及分离系数β_(Al/RE)的影响规律。结果表明,当环烷酸浓度为0.53 mol/L,有机皂化度为50%时,有机相与铝含量小于0.35 g/L的镨钕料液以0.5∶1的相比(O/A)在常温下萃取可将镨钕料液中99%以上的铝萃取分离,稀土损失率3%左右,满足镨钕料液对铝含量的要求。最优工艺条件下的萃取反应分相快,无第三相,不发生乳化,为连续萃取分离镨钕料液中铝的生产工艺提供了基础数据。     

HDEHP在硫酸溶液中萃取分离轻稀土性能研究

研究了 HDEHP在硫酸溶液中萃取分离轻稀土离子时有机相浓度、皂化剂类型、有机相皂化率、料液酸度对萃取饱和容量、分配比、分离系数的影响 ,确定了最佳萃取工艺参数 ,测定了轻稀土离子的分配比和分离系数。     

P204-HCl-H3cit体系中镧铈分配比及分离系数研究

针对P204萃取剂在HCl体系中高酸度下镧铈分离系数较低的问题,研究了含有柠檬酸(H3cit)的P204-HCl体系中,料液酸度与柠檬酸浓度对镧铈分配比和分离系数及萃取容量的影响.采用FT-IR方法分析了镧铈分离系数提高的机理.实验结果表明:在P204-HCl-H3cit体系中,镧铈的分配比和分离系数随酸度的增大而降低,随柠檬酸浓度的增加而提高,稀土元素的萃取容量随柠檬酸浓度的增大而提高.当料液酸度pH值为1.0、柠檬酸浓度为0.25mol/L时,镧和铈的分离系数为4.1,稀土的最大萃取容量为24 g/L,其指标优于相同酸度下的皂化P204-HCl体系.     

P204-HCl-H3cit体系分离镨钕的研究

针对P204萃取剂在HCl体系中pH＜2.0条件下镨钕分离系数较低的问题, 研究了含有柠檬酸(H3cit)的P204-HCl体系中, 料液酸度与柠檬酸浓度对镨和钕分配比和分离系数及萃取容量的影响. 用回归分析法建立了以料液酸度和柠檬酸浓度为变量的二元一次线性回归方程, 该方程得到的料液酸度、柠檬酸浓度对分配比和分离系数关系图表明: 在P204-HCl-H3cit体系中, 镨钕的分配比和分离系数随酸度的增大而降低, 随柠檬酸浓度的增加而提高, 稀土元素的萃取容量随柠檬酸浓度的增大而提高. 采用FT-IR方法分析了镨钕分离系数提高的机制. 当料液酸度pH=1.0, 柠檬酸浓度=0.25 mol·L-1时, 镨和钕的分离系数为1.54, 稀土的最大萃取容量为30 g·L-1, 其指标优于相同酸度下的皂化P204-HCl体系.     

Study on separation of rare earth elements in complex system

The effect of the feed acidity,acetic acid concentration and rare earth concentration on the distribution ratio,separation coefficient and extraction capacity of light rare earth elements were studied in the P204(DEHPA)-HCl system and P507(HEH/EHP)-HCl system both containing acetic acid,respectively. The results showed that the distribution ratio and separation coefficient decreased with increasing of acidity,and increased with increasing of acetic acid concentration and rare earths concentration,and the extraction capacity increased with increasing of acetic acid concentration. When pH value of feed was 2.0,[RE]/[acetic acid] was 1:1 and rare earth concentration 0.35 mol/L,in P204(DEHPA) -HCl system with acetic acid,the maximum separation coefficient(β) reached to βCe /La=4.09,βPr/Ce=1.96 and βNd/Pr=1.53,and the separation ability of this extraction system was better than P507(DEHPA)-HCl system.     

Study on separation of rare earth elements in complex system

The effect of the feed acidity, acetic acid concentration and rare earth concentration on the distribution ratio, separation coefficient and extraction capacity of light rare earth elements were studied in the P204(DEHPA)-HCl system and P507(HEH/EHP)-HCl system both containing acetic acid, respectively. The results showed that the distribution ratio and separation coefficient decreased with increasing of acidity, and increased with increasing of acetic acid concentration and rare earths concentration, and the extraction capacity increased with increasing of acetic acid concentration. When pH value of feed was 2.0, [RE]/[acetic acid] was 1:1 and rare earth concentration 0.35 mol/L, in P204(DEHPA)- HCl system with acetic acid, the maximum separation coefficient(β) reached to β_{Ce /La}=4.09, β_Pr/Ce=1.96 and β_Nd/Pr=1.53, and the separation ability of this extraction system was better than P507(DEHPA)-HCl system.     

240#新型环烷酸萃取铝的研究

探讨了有机相皂化值、氯化铝溶液起始pH、萃取温度、萃取时间、相比及环烷酸浓度对240#新型环烷酸萃铝饱和容量的影响及损失率情况。实验结果表明,在有机相组成为20%环烷酸+20%异辛醇+60%磺化煤油(有机相酸值为0.75 mol·L^-1),皂化值0.05~0.15 mol·L^-1,萃取温度25℃,萃取时间60 min,相比O/A(有机相与水相体积比)=1/1,pH为3.51的条件下时,240#新型环烷酸分相效果好,无三相和乳化现象产生。在皂化值为0.10 mol·L^-1时,萃铝饱和容量为0.055~0.056 mol·L^-1之间,较传统180#常用环烷酸高出14%,溶解损失及萃铝饱和容量损失总量较传统180#常用环烷酸的损失量低,避免了传统180#环烷酸萃取过程粘度大、流动性差,易产生乳化现象。盐酸反萃时,负载环烷酸铝的反萃率相当,均达99.40%以上。混合稀土料液中的铝经过2级连续萃取后,萃余液中Al3+的含量降为540 mg·L^-1,可以替代中和除杂过程制备稀土料液;经过3级连续萃取后,萃余液中Al3+的含量降为81 mg·L^-1,能实现用低价的碳酸盐代替高价草酸沉淀稀土产品,降低生产成本。在除铝过程中,240#新型环烷酸能够替代传统180#环烷酸的使用。     

环烷酸萃取脱除废旧稀土荧光粉酸浸液中铁铝

研究了废旧稀土荧光粉酸浸液在环烷酸萃取过程中关于铁、铝杂质的除杂效果，考察环烷酸对于铁、铝、稀土的选择性；有机相组成、氨水浓度、温度对分离效果的影响；水洗温度、水洗相比对水洗效果的影响；盐酸浓度、相比、反萃时间对反萃效果的影响.结果表明:选择环烷酸:异辛醇:磺化煤油体积比为20:20:60、氨水浓度为2 mol/L、温度为20 ℃、氨水滴加速度为3 mL/min时，分离效果较优；水洗温度为40 ℃、相比（A/O）为2时，铁铝稀土的洗脱率分别为1.5%、4.2%和26.4%；反萃剂盐酸浓度为3 mol/L、反萃相比（A/O）为1、反萃时间为20 min时，铁、铝、稀土萃取率分别高达99.5%、99.8%和99.8%.      

稀土元素的环烷酸萃取研究进展

溶剂萃取法是分离提纯稀土的一种有效方法,由于萃取剂的不同导致萃取分离稀土元素的效果不一。本文主要综述环烷酸用作稀土元素萃取剂的萃取化学研究进展。     

Separation of aluminum from rare earth by solvent extraction with4-octyloxybenzoic acid

Leaching method is usually used to extract rare earth(RE) elements from ion adsorbed RE ores.In the leaching process,some impurities such as aluminum(Al) enter the leaching solution.The separation of Al from RE by carboxylic acid extractant 4-octyloxybenzoic acid(POOA) was studied in this article.By changing the pH value,temperature,solvent,saponification degree and other parameters,the extraction and separation performance of POOA in chloride system was systematically studied.Through specific e...     

Study on separation technology of Pr and Nd in D₂EHPA-HCl-LA coordination extraction system

The separation coefficient of Nd/Pr was lower in D2EHPA-HCl system. Pointing to this problem,the effect of the acidity of feed and the concentration of lactic acid on the distribution ratio,separation coefficient and extraction capacity was investigated in unsaponified D2EHPA-HCl-LA system,and the regression equations were calculated in this paper. The results showed that the distribution ratio and separation coefficient both increased with decreasing of feed acidity and increasing of the lactic acid concentration,and the extraction capacity increased with increasing of lactic acid concentration in D2EHPA-HCl-LA system. When the pH value of the feed was 3.5 and lactic acid concentration was 0.6 mol/L,the max separation coefficient was 1.57,and the extraction capacity was 27.87 g/L.     

Study on separation technology of Pr and Nd in D2EHPA-HCl-LA coordination extraction system

The separation coefficient of Nd/Pr was lower in D₂EHPA-HCl system. Pointing to this problem, the effect of the acidity of feed and the concentration of lactic acid on the distribution ratio, separation coefficient and extraction capacity was investigated in unsaponified D₂EHPA-HCl-LA system, and the regression equations were calculated in this paper. The results showed that the distribution ratio and separation coefficient both increased with decreasing of feed acidity and increasing of the lactic acid concentration, and the extraction capacity increased with increasing of lactic acid concentration in D₂EHPA-HCl-LA system. When the pH value of the feed was 3.5 and lactic acid concentration was 0.6 mol/L, the max separation coefficient was 1.57, and the extraction capacity was 27.87 g/L.