Separation of Tb~(3 ) , Dy~(3 ) , Ho~(3 ) , Er~( 3 ) with Solvent Impregnated Resins Containing Di-(2,4,4-trimethylpentyl) Phosphinic Acid

Separation of Tb~(3 ) , Dy~(3 ) , Ho~(3 ) , Er~( 3 ) with Solvent Impregnated Resins Containing Di-(2,4,4-trimethylpentyl) Phosphinic Acid     

Study of Transport and Separation of Rare Earth Ions through the Emulsion Liquid Membrane of Bis(2,4,4-trimethylpentyl)phosphinic Acid-Span 80-Toluene

It is indicated from a study of transport of rare earth ions through the emulsion liquid mem-brane of bis(2,4,4-trimethylpentyl)phosphinic acid-Span 80-toluene that transporting rare earth ions com-pletely and rapidly was realized under the optimum experimental conditions:1.0×10~(-3)～3.0×10~(-3)mol/Lbis(2,4,4-trimethylpentyl)phosphinic acid and 2%～4%(W/V)Span 80 in toluene solution as membranephase,0.50～2.0 mol/L HCl as inner phase,rare earth ion solutions with pH 3.5～5.0 as outer phase.Ac-cording to the differences of transport behavior for rare earth ions,it is possible to separate rare earth ionsfrom mixed solutions of rare earth ions by this liquid membrane system.     

Extraction of molybdenum from weak acid rhenium-containing solutions

The possibility of extracting molybdenum from weak acid (pH 2 to 3) rhenium-containing solutions with the non-specific extractant Aliquat 336 is studied. A mechanism for the temperature influence on extraction and in particular for the extraction of molybdenum and rhenium is proposed. It is shown that the selectivity coefficient (β = D_Mo/D_Re) depends on the concentrations of both elements and also on the NO₃^? concentration in solution. When the concentration of molybdenum and nitrate ions increases, β increases. Increasing temperature has the same effect. A modifier is essential. At low rhenium concentrations it is better to use high molecular weight alcohols (as modifier), and at high concentrations it is better to use acetophenone. The authors believe that the investigations can be generalized and that analogous results can be expected if trialkylamine (for example, trioctylamine) is used.     

Extraction and Separation of Thorium and Ytterbium with Bis(2,4,4-Trimethylpentyl) Phosphinic Acid Using a Hollow Fiber Membrane Extractor

Ｔｈｅｅｘｔｒａｃｔｉｏｎｔｅｃｈｎｏｌｏｇｙｏｆｈｏｌｌｏｗｆｉｂｂｅｒｍｅｍｂｒａｎｅ (ＨＦＭ)ｉｓａｎｅｗｋｉｎｄｏｆｓｅｐａｒａｔｉｏｎｍｅｔｈｏｄｃｏｍｂｉｎｉｎｇｐｒｏｃｅｓｓｅｓｏｆｌｉｑｕｉｄ ｌｉｑｕｉｄａｎｄｍｅｍｂｒａｎｅｅｘｔｒａｃｔｉｏｎ ,ｗｈｉｃｈｈａｓｓｅｖｅｒａｌａｄｖａｎｔａｇｅｓｏｖｅｒｃｏｎｖｅｎｔｉｏｎａｌｅｘｔｒａｃｔｏｒｓ[1,2 ] ,ｅ .ｇ .,ａｖｅｒｙｈｉｇｈｉｎｔｅｒｆａｃｉａｌａｒｅａｐｅｒｕｎｉｔｅｘ ｔｒａｃｔｏｒｖｏｌｕｍｅａｎｄｎｏｐｒｏｂｌｅｍ…     

Extraction of molybdenum,nickel and aluminium from spent Ni–Mo hydrodesulphurization (HDS) catalyst in oxalic acid solutions

ABSTRACT

Dissolution behaviour of metals in Ni–Mo hydrodesulphurization catalyst waste was investigated in a 1?L jacketed glass reactor. Samples were roasted at 500°C in a tube furnace for the removal of C and S prior to the dissolution experiments. It was determined that roasted samples consisted of mainly 27.692% Al, 20.238% Mo, 5.267% Ni and 4.331% P. Unmilled samples were used for dissolution experiments because dissolution experiments carried out with milled and unmilled samples showed that milling has no significant effect on the dissolution rate. Oxalic acid solutions with 0.25–1 M, reaction temperatures of 25–70°C and solid to liquid ratios of 10–100?g?L^?1 were used as experimental parameters. It was found that the dissolution behaviour of Ni is different from Al, Mo and P. 92% of Mo, 19% of Ni, 28% of Al and 72% of P were dissolved at optimum dissolution conditions.     

CL-Cyanex272萃取色层法深度净化钴溶液

以苯乙烯为单体,二乙烯苯为交联剂,Cyanex272为萃取剂,采用乳液悬浮聚合法制备CL-Cyanex272萃淋树脂。采用静态吸附法探究了Co浓度、温度、pH、皂化度、时间等因素对CL-Cyanex272萃淋树脂吸附Co、Ni、Mg的影响;采用萃取色层法探究了连续动态过程中萃淋树脂对含Co溶液净化的影响。结果表明：当料液pH=6、皂化度为100%时,CL-Cyanex272萃淋树脂对Co的吸附量达21.4 mg/g;控制皂化度≥70%、料液pH≥5时,Co与Ni、Co与Mg的分离效果较好,其分离系数分别达到1 697和18;动态吸附试验中CL-Cyanex272萃淋树脂可将料液中Co的浓度从80.15%提纯到99.9996%。本研究为CL-Cyanex272萃淋树脂用于工业纯化Co溶液提供良好的依据。     

A novel extractant bis(2-ethylhexyl) ((2-ethylhexylamino)methyl) phosphine oxide for cerium(IV) extraction and separation from sulfate medium

By introducing the amine group into phosphorus extractant, a novel aminophosphine compound bis(2-ethylhexyl) ((2-ethylhexylamino)methyl) phosphine oxide (DEHAPO, abbreviated as A) was synthesized for the extraction of cerium (IV) (Ce(IV)) from sulfate medium (H₂SO₄). The influence factors including extractant concentration, H₂SO₄ concentration and temperature on the Ce(IV) extraction were investigated and discussed. It is found that the extraction ability of Ce(IV), thorium (IV) (Th(IV)) and rare earths (REs(III)) (La, Gd, Yb) decreases in sulphate medium in the following order: Ce(IV) > Th(IV) > REs(III). The extraction process is an exothermic reaction and the thermodynamic parameters were calculated. The extracted complex of Ce(HSO₄)₂SO₄·A in loaded organic solution was identified by the slope methods and further proved by FT-IR spectral analysis. Stripping studies indicate that Ce(IV) can be effectively stripped from the organic phase. The results of separation factors (β) and saturation loading capacity demonstrate that DEHAPO could be used to selectively extract Ce(IV) from sulphate medium with high separation efficiency and good extraction ability.     

Cyanex272浸渍树脂萃取色层法分离铥、镱、镥

研究了不同温度、淋洗液酸度、稀土负载量、淋洗液流速及装柱树脂高度对Cyanex272浸渍树脂萃取色层法分离Tm, Yb, Lu的影响和柱参数. 结果表明, 在温度为30 ℃, 梯度淋洗酸度为0.5, 0.6, 1.5 mol·L-1, 稀土负载量为0.3%, 淋洗液流速为1.0 ml·cm-2·min-1,装柱树脂高度为480 mm(柱内径为16 mm)的条件下, 对Tm, Yb, Lu富集物分离效果较好.     

Cyanex272与HEHEHP混合体系萃取分离重稀土的研究

选定了ＨＥＨＥＨＰ与Ｃｙａｎｅｘ ２７２组成混合体系,确定了萃取体系的最佳组成,测定了该体系的萃取容量、反萃酸度以主相邻重稀土元素之间的分离系数,考察了体系萃取性能的主要影响因素。     

三甲氧基苯基荧光酮光度法测定微量钼

研究了三甲氧基苯基荧光酮光度法测定微量钼的方法。在 0.16mol/L磷酸介质中 ,加入适量乳化剂OP ,钼 与显色剂形成 1∶1的橘红色络合物 ,其最大吸收波长在 5 2 5nm处 ,摩尔吸光系数ε =1.3× 10 5,于 2 5mL溶液中 ,钼质量在 0～2 0 μg范围内符合比尔定律。方法具有较高的选择性 ,已用于钢铁中微量钼的测定 ,获得令人满意的效果。     

新型萃取剂Cyanex272在溶剂萃取稀土中的应用

通过新型萃取剂Ｃｙａｎｅｘ２７２同Ｐ２０４和Ｐ５０７的对比预示了Ｃｙａｎｅｘ２７２分离稀土的景，并介绍了近期Ｃｙａｎｅｘ２７２溶剂萃取分离稀土的研究动态，在此基础上提出几点建议。     

Extractant(2,3-dimethylbutyl)(2,4,40-trimethylpentyl) phosphinic acid(INET-3) impregnated onto XAD-16 and its extraction and separation performance for heavy rare earths from chloride media

(2,3-Dimethylbutyl)(2,4,40-trimethylpentyl)phosphinic acid(INET-3) was impregnated onto dry macroporous resins XAD-16 and pretreated XAD-16 with ethyl alcohol and HCl(Pre-XAD-16) to prepare the solvent impregnated resins SIRs-INET-3/XAD-16 and SIRs-INET-3/Pre-XAD-16. The molecular weight distribution of the low molecular weight(LMW) polymers washed off by ethyl alcohol during XAD-16 pretreatment was determined by gel permeation chromatography(GPC). The macroporous resins(XAD-16 Pre-XAD-16), the corresponding solvent impregnated resins(SIRs-INET-3/XAD-16 SIRs-INET-3/Pre-XAD-16) and the PVA coated SIRs-INET-3/Pre-XAD-16 with boric acid as cross-linking agent were characterized by FT-IR, SEM-EDS and TGA. The effects of XAD-16 pretreatment and PVA coating technology on RE(III) adsorption equilibrium time, INET-3 losses during extraction and adsorption capacity were investigated. The adsorption kinetics, selectivity and stripping behaviors of SIRs-INET-3/XAD-16 were further studied. The washed off LMW polymers had the Mn of 36,656, Mw of 40,310 and polydispersity coefficient of 1.10. The SIRs-INET-3/XAD-16 had shorter equilibrium time,less INET-3 loss and more Tm(III) adsorption capacity than the SIRs-INET-3/Pre-XAD-16. The PVA coated SIRs-INET-3/Pre-XAD-16 had less INET-3 loss and more Tm(III) adsorption capacity but longer equilibrium time than the uncoated SIRs-INET-3/Pre-XAD-16. The adsorption of RE(III) on the SIRsINET-3/XAD-16 followed the pseudo-second-order kinetic model. The Tm(III) accumulative adsorption amounts onto SIRs-INET-3/XAD-16 after eight extraction stages was 23.6 mg/g. The separation factors of adjacent heavy RE(III) β_(Er/Ho), β_(Tm/Er), β_(Yb/Tm) and β_(Lu/Yb) values were 1.76, 2.59, 2.56 and 1.19,respectively. The adsorbed Lu(III) onto the SIRs-INET-3/XAD-16 can be stripped completely by 1.0 mol/L H_2SO_4.     

Extraction of gold(III) in hydrochloric acid solution using monoamide compounds

The extraction and separation properties of Au(III) using two monoamide compounds, N,N-di-n-octylacetamide (DOAA) and N,N-di-n-octyllauramide (DOLA), which have different side chain lengths attached to the carbonyl carbon (CH₃ for DOAA and n-C₁₁H₂₃ for DOLA), were investigated. The solvent extraction of some precious and base metals (Au(III), Pd(II), Pt(IV), Rh(III), Fe(III), Cu(II), Ni(II) and Zn(II)) in HCl solutions was carried out using DOAA and DOLA diluted with n-dodecane and 2-ethylhexanol. A good selectivity for Au(III) extraction with 0.5 M extractant is obtained at lower HCl concentrations (< 3.0 M) in both systems. The extractability of Au(III) with DOAA is greater than that with DOLA. In the 0.5 M DOAA–3.0 M HCl system, a third phase is formed when the Au(III) concentration in the initial aqueous phase is over 39 g/L. In contrast, third phase formation is not found in the 0.5 M DOLA–3.0 M HCl system, and its loading capacity of Au(III) is about 79 g/L. The Au(III) extracted in the organic phase is effectively back-extracted by 1.0 M thiourea in 1.0 M HCl solution in both systems, while some thiourea is precipitated using the organic phase containing 20 g/L of Au(III). The back extraction of Au(III) using water is poor in the DOAA system, but possible in the DOLA system.     

Extraction of Fe(III) from hydrochloric acid solutions using Amberlite XAD-7 resin impregnated with trioctylphosphine oxide (Cyanex 921)

Ferric ions were efficiently removed from HCl solutions using Amberlite XAD-7 resin impregnated with trioctylphosphine oxide (Cyanex 921). Iron was removed under the form HFeCl₄ through direct binding on the resin or by extraction with Cyanex 921 involving a solvation mechanism. High concentrations of HCl and intermediary extractant loadings were required for maximum sorption efficiency and rationale use of the extractant. At intermediary extractant loading (in the range 300–450 mg Cyanex 921 g^− 1) the maximum sorption capacity increased with extractant loading. Maximum sorption capacity slightly increased with temperature, the reaction is endothermic and the enthalpy change was found close to − 30.8 kJ mol^− 1. Sorption isotherms were fitted with the Langmuir equation and maximum sorption capacity reached values as high as 20–22 mg Fe g^− 1 in 3 M HCl solutions. Despite the good fit of experimental data with the pseudo second-order rate equation, sorption kinetics was controlled by the resistance to intraparticle diffusion. The intraparticle diffusion coefficient (D_e) varying in the range 1.2 × 10^− 11–4.7 × 10^− 10 m² min^− 1 was found to increase with metal concentration and with temperature, while varying the extractant loading it reached a maximum at a loading close to 453 mg Cyanex 921 g^− 1. The desorption of Fe(III) can be achieved using 0.1 M solutions of nitric acid, sulfuric acid, sodium sulfate and even water, maintaining high efficiencies for sorption and desorption for at least 5 cycles.     

三烷基氧膦萃取铱的动力学研究

利用恒界面池法研究三烷基氧膦(TAPO)-煤油从盐酸介质中萃取Ir(Ⅳ)的动力学。测定了水相金属浓度，水相氢离子浓度，三烷基氧膦浓度，温度，搅拌速度等对萃取速率的影响，并得出萃取速率规律。     

Cyanex272萃取分离Co(Ⅱ)-Al(Ⅲ)体系的研究

研究了Cyanex272从盐酸介质中萃取Co(Ⅱ)和Al(Ⅲ)的性能。考察了平衡相酸度、振荡时间和平衡相温度对萃取的影响,结果表明,分配比在一定时间内随振荡时间、平衡相温度的增加而增加。在溶液温度为40℃、pH3.38、振荡时间为25min时,Al(Ⅲ)能很好地被萃取;而在pH4.08、振荡时间为20min时,Co(Ⅱ)能很好地被萃取。萃取Co(Ⅱ)和Al(Ⅲ)的过程为吸热过程,随着温度的升高两离子的分配比都增大。在振荡时间为25min、溶液pH3.38、温度为40℃时,两离子的分离系数最大,Co(Ⅱ)-Al(Ⅲ)能很好地分离。