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 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.     

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.     

环烷酸萃取体系中单一稀土和铝的分配比及分离系数的研究

对不同萃取剂皂化值、料液酸度和铝浓度条件下,单一稀土和铝在环烷酸体系中的分配比和分离系数进行研究,结构表明料液的酸度较高时,皂化值为0.35 M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。铝离子浓度较低时,料液酸度较高的条件下仍可实现稀土和铝的较好分离,而铝离子浓度较高时(150 mmol/L),料液酸度较高不利于稀土和铝的分离。     

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.     

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。     

合金渣中铪的MIBK萃取分离试验

采用MIBK作为萃取剂,在盐酸体系下,对含铪合金渣中的铪进行萃取分离试验,主要考察合金渣中含量较高的锆、钛、铬和铪在萃前液不同氢离子浓度、NH4SCN浓度、有机相HSCN浓度及相比下的分离性能。结果表明,铪和锆钛分离难度较大、和铬分离较易,铪的最优分离条件为:萃前液氢离子浓度0.96mol/L、萃前液NH4SCN浓度2.56mol/L、有机相HSCN浓度2.73 mol/L、相比1。在最优条件下,铪和锆的相对分离系数为6.63,铪的分配比为1.79,对于锆含量较低的合金渣,可以有效提升锆铪分离效率,钛最好于萃取分离前进行分离。     

P507-N235载酸有机相分解稀土的试验研究

P507-N235复合有机相能很好的萃取分离稀土元素.为有效利用P507-N235复合有机相中的余酸,对载酸有机相分解稀土的试验进行了研究.结果表明,分解碳酸钕时,较优的工艺参数为料浆浓度72.5 g/L、浸出时间30 min、相比V_O:V_A=1:1（有机相与水相的体积比, 下同）,在此条件下,30%P507+25%N235+45%煤油体系对Nd的萃取容量为20.16 g/L(按REO计,下同),有机相中余酸利用率为52.6%,且体系分相效果较好;分解氢氧化钕时,较优的工艺参数为料浆浓度73.3 g/L、浸出时间50 min、相比V_O:V_A=1:1,此时Nd的萃取容量可达21.6 g/L,有机相中余酸利用率为53.7%.实验证明了此方案的可行性,有机相中的残酸利用效果较好,可以实现载酸有机相的循环使用.      

低浓度氢氟酸体系中MIBK萃取分离钽铌的研究

开展了低浓度氢氟酸体系中MIBK萃取分离钽铌的研究,考察了萃取时间、萃取相比、氢氟酸浓度、钽铌浓度、钽与铌质量比对萃取分离过程的影响。结果表明,在始氢氟酸浓度0.5mol/L、钽铌总浓度60g/L、萃取相比(O/A)为5、钽与铌质量比2的条件下萃取5min可获得最佳的钽铌分离效果,钽铌分离系数高达50 000。     

Study on a novel flat renewal supported liquid membrane with D2EHPA and hydrogen nitrate for neodymium extraction

The Nd(III) extraction in flat renewal supported liquid membrane(FRSLM),with polyvinylidene fluoride membrane and renewal solution including HNO3 solution as the stripping solution and di(2-ethylhexyl) phosphoric acid(D2EHPA) dissolved in kerosene as the membrane solution,was investigated.The effects of pH in the feed phase,volume ratio of membrane solution to stripping solution,concentra-tion of HNO3 solution and concentration of carrier in the renewal phase on extraction of Nd(III) were also studied,respectively.As a result,the optimum extraction conditions of Nd(III) were obtained when concentration of HNO3 solution was 4.00 mol/L,concentration of D2EHPA was 0.100 mol/L,and volume ratio of membrane solution to stripping solution was 1.00 in the renewal phase,and pH was 4.60 in the feed phase.When initial concentration of Nd(III) was 2.00×10-4 mol/L,the extraction percentage of Nd(III) was up to 92.9% in 75 min.     

P204从硫酸体系萃取镓性能研究

研究了P204从硫酸体系萃取镓的性能,分别考察了料液酸度、萃取剂浓度、时间、浓度等对镓萃取与反萃的影响并绘制等温线,确定并模拟逆流试验过程。结果表明:料液含0.3g/L Ga^3+,pH=1.2,有机相采用20%P204(体积分数)+磺化煤油,按相比O/A=1∶3,25℃萃取8min,经过3级逆流萃取,镓萃取率可达到99.33%,负载有机相用1.0mol/L H2SO4溶液反萃,按相比O/A=10∶1,反萃温度25℃,反萃时间10min,经过3级逆流反萃,镓反萃率达98.99%,镓浓度富集近30倍。反萃液中的镓经氨水中和沉淀、焙烧后,可得到氧化镓产品。     

高铁、高硅溶液中萃取钼

沉淀钼酸铵后的溶液含铁、硅较高,为了综合回收利用钼,采用N235萃取分离钼。对影响萃取分离钼的因素进行考察。结果表明,采用20%N235+10%仲辛醇+70%的煤油体系在下述最佳工艺条件下可有效实现钼、硅、铁的分离,钼萃取率达到95.0%以上:萃取平衡时间3～5min、酸浓度5～20g/L、级数4～5级、相比O/A=1/2～1/4。     

N1923从铜SX-EW电解液中萃取除铁

研究了采用萃取剂N1923从SX-EW电解液中萃取铁。在萃取过程中添加改质剂异辛醇能够有效改善萃取过程的分相性能。在萃取剂浓度为10%、萃取相比2/1时萃取性能较好,能够从含铁3 g/L的电积液中单级萃铁率达到60%,在萃取铁的过程中几乎不萃取其它元素,电积液的酸度对萃取影响较小。萃取铁后的负载有机相用2 mol/L氢氧化钠在相比为2/1时反萃效果较好,并且有机相的循环性较好。另外,萃取剂经由夹带进入SX系统对萃取铜几乎没有影响。     

HBL101从镍钼矿焙烧料高酸浸出液中直接萃取钼的研究

采用新型萃取剂HBL101从镍钼矿焙烧料高酸浸出液中直接萃取钼。考察有机相组成、料液酸度、相比、振荡频率、平衡时间、温度对钼萃取过程的影响,并绘制了HBL101萃钼等温曲线。结果表明,在优化的工艺条件下,钼萃取率达96.8%以上,有机相饱和容量为12.09g/L;负载有机相用纯水洗涤后经3级逆流氨水反萃,钼反萃率达99.9%以上,实现了钼镍分离及钼的富集转型。     

氯盐体系铟萃取富集试验

针对氯盐体系铟的萃取进行萃取体系、酸度、萃取剂浓度、相比和时间条件试验,对反萃过程中关键影响因素盐酸浓度进行试验。最佳萃取工艺参数为:有机相30%P204、相比(O/A)=1/3、皂化率60%、初始水相pH=0.5、室温混合5min;铟一级萃取率能够达到97.01%,三级逆流萃取能够稳定达到99.5%。反萃工艺参数为相比10/1、盐酸浓度3mol/L、室温混合5min,一级反萃率75.52%,三级反萃率达到100%。经萃取、洗涤、反萃后,铟回收率达到96.8%。     

二苯胍固相萃取钯的探讨

基于Pd与二苯胍(DPG)形成的络合物能够被MCI-GEL树脂固相萃取柱萃取、富集,建立了一种固相萃取钯的方法。经过实验发现:当溶液中n_DPG∶n_Pd=0.5,盐酸介质浓度为0.05 mol/L,过柱流速为10 mL/min,Pd的萃取率可达99%;通过流出曲线测定出MCI-GEL树脂固相小柱的萃取容量为4.86 mg/g;筛选出最佳洗脱液为酸性硫脲溶液,且3.0 mL 20 g/L的酸性硫脲溶液以1.0 mL/min 的洗脱速度能完全洗脱4.86 mg/g钯。在0.05～2.0 mol/L盐酸介质中,利用MCI-GEL树脂固相小柱对合成试样溶液中Pd进行分离和测定,通过计算分离系数,证明在0.05 mol/L 盐酸介质中,Pd可与Pt、Fe、Ni、Cu、Zn离子定量分离。     

从含锰钴镍浸出液中萃取回收锰

采用P204作为萃取剂,磺化煤油为稀释剂,从锰钴镍溶液中二级萃取分离锰,有机相反萃取富集锰,考察各因素对锰萃取率及分离系数的影响并确定最优条件。结果表明,在室温下,一级萃取相比O/A=2.5,P204含量30%,pH=3.5,皂化率30%,锰萃取率为62.39%;二级萃取在P204含量30%,皂化率30%,O/A=2,锰的总萃取率达98.06%,锰与钴、镍分离系数分别为90.11、92.33。萃取液经硫酸反萃洗钴镍,按相比O/A=10,酸度70 g/L,可洗去85%以上的钴和镍。洗钴镍后液经硫酸反萃锰,按相比O/A=4,酸度110 g/L,可反萃98.27%的锰,反萃液钴、镍的浓度小于0.5 g/L。     

Solvent extraction of cadmium from sulfate solution with di-(2-ethylhexyl) phosphoric acid diluted in kerosene

In the present paper, solvent extraction process has been used for extraction of cadmium from sulfate solution using di-(2-ethylhexyl) phosphoric acid (D2EHPA) with 1% isodecanol in kerosene diluent expected from industrial effluents or leaching of ores/secondary materials. Different process parameters such as pH, contact time, extractant concentration, O/A ratio etc. were investigated. Results demonstrated that quantitative extraction of cadmium was feasible from 4.45 mM cadmium feed solution in single stage at equilibrium pH 4.5, time 2 min and O/A ratio 1:1 with 0.15 mM D2EHPA. The extraction mechanism of cadmium from sulfate solution by D2EHPA in kerosene could be represented at equilibrium by Cd²⁺ + 3/2 (H₂A₂)_org ⇔ CdA₂(HA)_org + 2H⁺. The loading capacity of 0.15 mM D2EHPA in sulfate solution was determined to be ∼ 8.9 mM cadmium. The loaded cadmium was effectively stripped using 180 g/L sulfuric acid. The metal or salt could be produced by electrolysis or crystallization from the stripped solution.     

Kinetics study on leaching of rare earth and aluminum from polishing powder waste using hydrochloric acid

In this study,a novel hydrometallurgical process consisting of hydrochloric acid three-stage countercurrent leaching and solvent extraction was proposed to recover rare earth oxide(REO) from the rare earth polishing powder waste(REPPW).The effects of HCI concentration,liquid-solid ratio(L/S ratio),temperature and time on the leaching yields of rare earths(in REO) and aluminum(in Al_2O_3) were studied.The result shows that the leaching yields of REO and Al_2O_3 are 90.96% and 43.89% respectively under the optimum leaching parameters of HCl concentration=8.00 mol/L,L/S ratio=4 mL/g,leaching temperature=353 K and leaching time=180 min.Meanwhile,the leaching kinetics of REO and Al_2O_3 were investigated in this study.The leaching behaviors of REO and Al_2O_3 follow a shrinking sphere/core model and the general leaching process is controlled by the surface chemical reaction.The leaching activation energies of REO and Al_2O_3 are 9.86 and 13.68 kJ/mol,respectively.The leaching yield of each substance in three-stage countercurrent leaching is improved substantially compared with single-stage leaching,with a change from 90.96% to 95.38% for REO and from 43.89% to 46.22% for Al_2O_3,respectively.Especially,the total concentration of REO in three-stage countercurrent leaching solution is greatly increased to above 300 g/L,and the acidity of which is decreased to ca.pH=2,which is conducive to subsequent solvent extraction directly.High purity REO(99.92%) is obtained by solvent extraction separation,oxalate precipitation and calcination.The total recovery yield of REO is 85.13%.