锡的溶剂萃取

综述了大量资料,论述了中性络合萃取剂、酸性及螯合萃取剂、胺类萃取剂及冠醚萃取剂从含锡溶液中萃取锡的试验结果。     

C272萃取剂在稀土分离中的研究进展

综述了C272对稀土萃取分离性能的研究,比较了萃取剂C272与P507的优缺点,并指出单一 C272未能在稀土萃取分离应用的原因.详细介绍了C272与其它萃取剂混合作为稀土分离的协同萃取剂,阐述了协同萃取剂具有良好的萃取性能,并克服了单一 C272萃取剂的不足,分析了C272与不同类型萃取剂协同萃取分离稀土的行为,并解...     

溶液中镍钴萃取分离技术研究状况

介绍了近年来溶液中镍钴分离技术研究状况及可用于各种溶液,如硫酸、盐酸、硝酸溶液中镍钴分离的萃取剂、萃取工艺及协萃体系。对于成分复杂的溶液,采用单一的萃取剂很难将镍、钴与其他杂质金属离子有效分离,而利用协萃体系可以得到较好的分离效果。介绍了几种协萃体系,如螯合萃取剂-有机羧酸萃取剂体系,羟肟萃取剂-羧酸萃取剂体系,羧酸萃取剂-有机磷类萃取剂体系,羟肟萃取剂-有机磷酸类萃取剂体系,羧酸萃取剂-吡啶羧酸酯体系,有机磷酸萃取剂-有机磷酸萃取剂体系,对镍钴萃取分离的效果。比较了这些协萃体系较单一萃取剂的优势,指出协萃体系将成为镍钴分离提纯的发展趋势。     

废旧钯萃取剂再生并同时回收铂族金属的研究

应用蒸馏法再生废旧钯萃取剂,不仅实现了钯萃取剂的再生,还能有效回收其中残留的铂族金属。主要考察了蒸馏温度、蒸馏时间对于废旧钯萃取剂萃取性能及其铂族金属回收率的影响。结果表明:蒸馏回收废旧钯萃取剂效果明显,具有高效、经济、环保的特点。蒸馏温度控制在135~140℃,蒸馏时间为8 h时,废旧钯萃取剂再生率为92.94%;对再生后萃取剂与新萃取剂进行红外光谱(IR)分析和萃取性能分析,结果表明:再生后的萃取剂性能稳定,主要官能团与新萃取剂完全一致;再生后的萃取剂总萃取率在99.92%~99.96%,而新萃取剂总萃取率在99.47%~99.90%,完全满足铂族金属萃取分离工艺的要求。通过经济分析,蒸馏1 L废旧钯萃取剂可节约成本600元,并且其中的铂族金属总回收率可达94.86%。     

酸性介质中萃取铟的研究

综述了在不同的酸性介质中，用不同的萃取剂萃取铟的研究。指出在硫酸介质中，萃取铟常用的萃取剂是酸性磷型萃取剂，如P204、P538、P5708、D2EHMTPA等；在盐酸介质中常用的萃取剂有胺类萃取剂、亚砜类萃取剂、中性氧磷萃取剂，如：N235、TOPO、石油亚砜等，并指出在萃取铟的过程中，影响萃取率的因素主要有：酸度、萃取剂浓度、水相中铟离子的浓度、VA：VO、萃取级数等。     

Mextral204P和Mextral336A混合萃取稀土元素的研究

向萃取剂Mextral204P中加入萃取剂Mextral336A构成混合萃取剂来萃取稀土元素,考察了混合萃取剂的配比、萃取时间、萃取相比、水相pH以及料液中稀土的浓度对萃取的影响。结果表明,当混合萃取剂中Mextral204P的摩尔分数为0.74时,混合萃取剂之间具有最大正协同作用,并且在萃取时间为4min、相比1∶1、料液pH=4时,萃取效果最好,最大钐负载高达23g/L。     

C_(272)及协萃剂C_(274)萃取分离稀土的性能试验

测定了新型萃取剂Ｃ２７２和Ｃ２７４的萃取稀土容量及其反萃取性能,进行了上述萃取剂串级萃取分离Ｔｍ／Ｙｂ和Ｙｂ／Ｌｕ的试验,确认Ｃ２７２和Ｃ２７４是萃取分离重稀土的优良萃取剂。     

钴镍协同萃取体系

评述了自１９６６年以来报道的有关钴协同萃取的文献，主要介绍了磷酸，羧酸以及磺酸类萃取剂与含氮螯合萃取剂或非螯合萃取剂组成的协同萃取体系，此外，对一些由胺类萃取剂加磺酸或羧萃取剂加吡啶羧酸酯组成的协同取也作了简单介绍，讨论了这些协同萃取体系萃取然的反应机理，特点及其潜在的应用价值。     

有机磷萃取剂的合成研究进展

有机磷萃取剂广泛应用于湿法冶金、原子能工业和环境科学等领域,在金属萃取方面占有重要地位。介绍和评述了国内外已商品化的有机磷萃取剂的合成工艺,展望了有机磷萃取剂的发展趋势,并指出了未来有机磷萃取剂的设计和合成方向。     

钒资源现状及有机磷类萃取剂萃钒的研究进展

介绍了全球的钒资源的主要分布、储量情况及其市场供需与应用状况。从中心结构、有效基团与空间效应、离子交换协同萃取三个方面综述了机磷(膦)类萃取剂的萃钒机理及其近年来萃钒的新型磷(膦)类萃取剂的研发与应用进展,指出了新型磷(膦)类型萃取剂的研发、新工艺的应用以及协同萃取是目前磷(膦)类萃取剂萃钒的主要研究方向。分析了酸性磷(膦)类萃取剂萃钒、中性磷类萃取剂萃钒和其他新型磷(膦)类萃取剂萃钒的不同萃取体系的萃钒机制。分析认为有机相的损失,萃取和反萃钒的步骤,萃取和分离时间较长,出现乳化现象等是当前萃取钒体系普遍存在的难点。因此需要不断开发新型高效萃取剂,发展清洁绿色萃取技术,在原萃取剂的基础上利用协同效应,探索新的萃取剂组合方式,更好地推进中国钒工业的发展。      

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。     

Solvent Extraction Separation and Recovery of Components from Scraps Containing Nickel and Cadmium

The solvent extraction separation of Cd²⁺ and Ni²⁺ by commercially available dialkyl-phosphoric (D2EHPA), phosphonic (PC-88A) and phosphinic acids (Cyanex 272) has been investigated. In each case cadmium is extracted at lower pH values than nickel. Under comparable conditions PC-88A and Cyanex 272 have an excellent ability to separate cadmium from nickel. The optimum pH ranges are 3.5-4.5 with PC-88A and 4.8-6.0 with Cyanex 272. The feasibility of cadmium-nickel separation by Cyanex 272 extractant have been tested in pilot-plant scale. Cadmium and nickel salt solutions have been recovered from solutions originating from the leaching of the electrode materials of Ni-Cd battery scraps. The nickel and cadmium salt solutions have further been processed to metal oxidehydrates which have been found in laboratory lists as suitable for production of negative and positive electrode materials of new Ni-Cd batteries.     

不同萃取体系分离微生物浸出液中低含量镍钴

采用P507一Cyanex272混合萃取体系分离微生物浸出液中的镍钴,实验结果表明该体系具有较好的协萃效应.结合低含量镍钴的微生物浸出液体系高酸度、低钴镍比的特点,对比了P507、Cyanex272和P507-Cyanex272三种萃取体系对镍钴的萃取分离效果,确定了在初始pH值1.5~2.2、对应的平衡pH值4.00~5.25条件下P507-Cyanex272协萃体系有较好的镍钴分离效果.系统考察了室温28℃下协萃体系各影响因素对镍钴分离的影响,确定协同萃取的最佳工艺为:P507与Cyanex272摩尔比3:2,皂化率60%,萃取剂体积分数10%,有机相(由萃取剂与煤油组成)和水相体积比1:4.在此条件下钻的一级萃取率为99.16%,镍钻分离系数为932.59.      

Determination of optimum process conditions for the extraction and separation of zirconium and hafnium by solvent extraction

Taguchi's method was used to determine the optimum conditions for separation of zirconium from hafnium by solvent extraction. The experimental conditions were studied in the range of 0.1 to 2.0 M for three different acids and TBP, D2EHPA or Cyanex 272 as extractant. The optimum extraction of zirconium was 71% when 2.0 M nitric acid and Cyanex 272 were used. The optimum zirconium/hafnium separation was also achieved using this combination.     

Study on the diffusion kinetics of adsorption of heavy rare earth with Cyanex272-P507 impregnated resin

Kinetics of adsorption of heavy rare earth with Cyanex272-P507 impregn ated resin was studied. The influences of temperature,concentration,granularit y of resin on the exchange degree were investigated by the limited bath method. The result showed that the controlling factor of RE3+/H+ diffusion on Cyanex272-P507 extraction resin was particles diffusion. The process of diffuse kinetics f itted well with the expression developed by Body model. The apparent activation energy was determined as 23.20 kJ/mol. The reaction order was 0.452. In addition,the constant of particles diffusion(D0) was 1.352×10-8 m2/S and the entropy of diffusion was-47.055 J/(mol·K).     

Extraction and stripping of rare earths using mixtures of acidic phosphorus-based reagents

Studies were carried out on the extraction characters of trivalent rare earths from chloride solutions using organophosphorus acids 2-ethylhexylphosphonic acid mono-(2-ethylhexyl) ester (HEHEHP) combined with [di-(2-ethylhexyl)-phosphoric acid (HDEHP),isopropylphosphonic acid 1-hexyl-4-ethyloctyl ester (HHEOIPP),bis(2,4,4-trimethylpentyl)-phosphinic acid (Cyanex 272),bis(2,4,4-trimethypentyl)-monothiophosphinic acid (Cyanex 302) or bis(2,4,4-trimethypentyl)-dithiophosphinic acid (Cyanex 301)] as extractants. The effect of the equilibrium aqueous acidity on the extraction was studied. According to the corresponding separation factors for adjacent pairs of rare earths,it could be concluded that HEHEHP and Cyanex 272 could be employed for the separation of Tm(Ⅲ),Yb(Ⅲ),Lu(Ⅲ) from the other rare earths. Taking Yb(Ⅲ) as an example,based on the different stripping acid,the potential of the stripping was estimated.     

Solvent extraction characteristics of thiosubstituted organophosphinic acid extractants

Organophosphorus reagents are well known in solvent extraction. Commercial operations for the separation of cobalt from nickel have been successfully carried out using organophosphoric, -phosphonic, and -phosphinic acid extractants. Two new reagents in this class are the mono and dithio analogs of the commercial dialkylphosphinic acid, Cyanex 272. The replacement of oxygen by sulfur in these reagents enables extraction to be carried out at much lower pH.Characterization of Cyanex 272, Cyanex 302 (bis-(2,4,4-trimethylpentyl)-thiophosphinic acid), and Cyanex 301 (bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid) has been undertaken. A comparison of the solvent extraction behavior of metallurgically important first-row transition metal ions from acidic sulfate solution by these reagents is reported. Distribution coefficients shift to lower pH with increasing sulfur substitution and decreasing pK_a of the extractant, the greatest effect being observed for nickel. Stoichiometry of the extraction reactions, and the nature of the metal complexes formed have been determined using slope analysis techniques and spectroscopic measurements.     

Mass transfer kinetics of yttrium(III) using a constant interfacial cell with laminar flow. Part II extraction with Cyanex 272

The yttrium(III) extraction kinetics and mechanism with bis-(2,4,4-trimethyl-pentyl) phosphinic acid (Cyanex 272, HA) dissolved in heptane have been investigated by constant interfacial cell with laminar flow. The data has been analyzed in terms of pseudo-first order constants. Studies on the effects of stirring rate, temperature, acidity in aqueous phase, and extractant concentration on the extraction rate show that the extraction regime is dependent on the extraction conditions. The plot of interfacial area on the rate has shown a linear relationship. This fact together with the strong surface activity of Cyanex 272 at heptane–water interfaces has made the interface the most probable location for the chemical reactions. The forward, reverse rate equations and extraction rate constant for the yttrium extraction with Cyanex 272 have been obtained under the experimental conditions. The rate-determining step has been also predicted from interfacial reaction models. The predictions have been found to be in good agreement with the rate equations obtained from experimental data, confirming the basic assumption that the chemical reaction is located at the liquid–liquid interface.     

新型萃取剂Cyanex272的制备及应用

概述了Ｃｙａｎｅｘ２７２新型萃取剂的制备方法及其在溶剂萃取中的应用     

Colorimetric estimation and some physicochemical properties of purified Cyanex 272

A technique for the colorimetric estimation of purified Cyanex 272 has been developed. The technique consists of the digestion of pure sample or its aqueous solution with concentrated nitric acid (70%)–perchloric acid (70%) mixture for 1 h. The oxidizing mixed acid quantitatively converts Cyanex 272 to a clear solution of orthophosphate that can be easily estimated by the molybdenum-blue colorimetric method at 830 nm. The method is sensitive with a molar extinction coefficient of ∼2.6×10⁴ and reproducible within ±2%. Applying this technique of analysis, the dimerization constant (K₂), distribution or partition coefficient (K_d) and ionization constant (K_a) of the purified Cyanex 272 (bis-2,4,4-trimethylpentylphosphinic acid, BTMPPA) have been estimated to be 190, 53 and 5.52×10⁻⁴, respectively.