Extraction Characteristics of Niobium(V) and Tantalum(V) on Trioctylmethyl Ammonium Chloride-Impregnated Polyurethane Foam

Abstract

A reagent-impregnated polymer material has been prepared with trioctylmethyl ammonium chloride (TOMAC) and polyurethane foam as a new type of extractant for niobium and tantalum. Niobium(V) and tantalum(V) can be easily concentrated from their hydrofluoric acid solutions with TOMAC-impregnated polyurethane foam. The log D value for tantalum(V) is more than 4 in the HF concentration range from 0.5 to 2 mol·L^?1. The recovery of tantalum(V) from hydrofluoric acid solutions containing a large amount of niobium(V) has been successfully carried out by a batch technique. Extraction characteristics of the present system are similar to solvent extraction rather than to conventional anion-exchangers with respect to the dependence of the value of log D on hydrofluoric acid concentration.     

Solvent Extraction Separation of Niobium(V), Tantalutn(V) or Titanium(IV), and Vanadium(V) by 2′-Hydroxy-4-methoxy-5′-methyl Chalkone Oxime (HMMCO) from Their Binary Mixtures

Abstract

2′-Hydroxy-4-methoxy-5′-methyl chalkone oxime (HMMCO) has been used for the solvent extraction separation of Nb(V), Ta(V) or Ti(lV), and V(V) from their binary mixtures. V(V) can be quantitatively extracted with HMMCO from 9 M hydrochloric acid. The green-colored chloroform extractable V(V)-HMMCO complex absorbs at a maximum at 630 nm. Nb(V), Ta(V), and Ti(IV) are not extracted at these conditions. However, these metals can be extracted from strong hydrochloric acid medium in the presence of potassium thiocya-nate. The yellow-colored complexes of Nb(V), Ta(V), and Ti(IV) absorb at a maximum at 380, 390 and 390 nm, respectively. The method is simple, rapid, and selective, and affords a clean-cut separation of vanadium from niobium, tantalum, or titanium which are usually present in alloys and ores.     

Distribution Studies of Zinc and Copper Salicylates with Tris(2-ethylhexyl)phosphate

Abstract

Tris(2-ethylhexyl)phosphate is proposed as an extractant for the solvent extraction of zinc and copper salicylate. The optimum extraction conditions are established by studying the various experimental parameters such as pH, sodium salicylate concentration, tris(2-ethylhexyl)phosphate concentration, equilibration period, and various diluents. The probable extracted species as ascertained by log D-log C plots is Zn(HSal)₂2T2EHP and Cu(HSal)₂2T2EHP. The method permits mutual separation of zinc and copper and can be used for separation and determination of zinc and copper in environmental and pharmaceutical samples.     

Extraction of monocarboxylic acids by trioctylmethylammonium di(2-ethylhexyl)phosphate

The laws of the interphase distribution of saturated monocarboxylic acids in the system with the binary extracanttrioctylmethylammonium di(2-ethylhexyl)phosphate were studied. The extraction isoherms of monocarboxylic acids by 0.2 M solution of trioctylmethylammonium di(2-ethylhexyl)phosphate in toluene were obtained, and it was shown that they are rectilinear. The extractibility of acids decreases in the following order: butyric > propionic > formic> acetic> lactic, which corresponds to the anion-exchange order for the initial salts of quaternary ammonium bases. The mechanisms of the distribution of monocarboxylic acids were proposed. The study of the extraction of acetic and propionic acids as a function of the acidity of the aqueous phase revealed that the acids are extracted most efficiently from acid solutions. A decrease in the distribution coefficients with an increasing pH of the aqueous phase is observed, which indicates the possibility of efficient reextraction of monocarboxylic acids from organic solutions.     

磷酸二(2-乙基己基)酯的合成研究

研究了用2-乙基己醇和三氯氧磷反应合成磷酸二(2-乙基己基)酯的方法,考察了原料配比、不同催化剂、反应温度、反应时间各因素对酯化反应的影响以及合理的后处理方法。     

Recovery and Separation of Lanthanum(III), Aluminum(III), Cobalt(II), and Nickel(II) from Misch Metal by Solvent Extraction Using Bis(2-ethylhexyl) phosphinic Acid

Abstract

This paper describes use of bis(2-ethylhexyl) phosphinic acid as a reagent for extraction and mutual separation of lanthanum(III), aluminum(II), cobalt(II), and nickel(II) in 1.0 mol/L sodium nitrate. The extraction and stripping behavior of the four metal ions has been investigated using the extractant in Solvesso #150 as a diluent. The mutual separation and recovery of the metal ions from their mixtures has been tested by multistage extraction with a conventional separator funnel. A set of separation schemes has also been proposed for a continuous countercurrent multistage extraction which is comprised of ten extraction stages, four scrubbing stages, and seven stripping stages. Lanthanum(III) and aluminum(III) are coextracted but separated by selective stripping into different concentrations of hydrochloric acid. Cobalt(II) can be extracted with the nickel(II)-preloaded extractant solution, whereas nickel(II) remains in the aqueous phase. The successful separation of these metal ions from a misch metal-simulated sample is presented.     

Extraction and Spectrophotometric Determination of Vanadium (V) from N-m-Tolyl-o-Methoxybenzohydroxamic Acid

Abstract

The reagent N-m-tolyl-o-methoxybenzohydroxamic acid is proposed for the rapid extraction and simultaneous Spectrophotometric determination of vanadium in the presence of commonly occurring metal ions. It forms an intense violet colored complex with vanadium and the complex can be extracted by chloroform from 6–8 M HCl. The violet complex obeys BeeR′s Law at λ_max (550 mm) with the molecular absorptivity 6.5 × 10³ and sensitivity 0.01 μg of V/cm². The effects of acidity, reagent concentration, and diverse ions on the extraction are discussed.     

Solvent extraction kinetics of Sm(Ⅲ),Eu(Ⅲ) and Gd(Ⅲ) with 2-ethylhexyl phosphoric acid-2-ethylhexyl ester

Solvent extraction kinetics of Sm(Ⅲ), Eu(Ⅲ) and Gd(Ⅲ) from hydrochloric acid have been focused on using2-ethylhexyl phosphoric acid-2-ethylhexyl ester(P507) with Anordning for Kontinuerlig Undersokning av Fordelningsfaktore vid Vatske Extraction(AKUFVE). Compared with the conventional set-up, some advantages emerge obviously, for example, fast phase separation, easy operation and convenience of kinetic data acquisition.First of all, the extraction mechanism was discussed based on the dimeric model of P507. Secondly, the effects of stirring speed were investigated and 420 r·min~(-1) was determined of the following experiments. The effects of pH, concentration of rare earth elements(REEs) and P507 on the extraction rate were analyzed. The results indicated that the extraction mechanism changed with the increasing concentration of P507. Then, the experiments with different temperature were carried out. It turned out that the values of apparent activation energy(E_a) for Sm(Ⅲ), Eu(Ⅲ) and Gd(Ⅲ) extracted by P507 were 26.80 kJ·mol~(-1), 13.40 kJ·mol~(-1) and11.10 kJ·mol~(-1) respectively, the resistance of the entire process was limited by diffusion or both of diffusion and reaction. Finally, the correlation equations were obtained, and the theoretical results fit with the experimental data well, most relative error was within ±30%.     

二安替比林－（2－甲氧基）苯基甲烷光度法测定钒

本文合成了二安替化林－（２－甲氧基）－苯基甲烷（ＤＡＯＭＭ）并用元素分析、红外分析对其进行了鉴定。在吐温２０和Ｍｎ（Ⅱ）存在下，ＤＡＯＭＭ与钒（Ｖ）反应，生成橙黄色产物，λｍａｘ＝４８０ｎｍ，摩尔吸收系数ε＝３．１×１０５Ｌ．ｃｍ－１、ｍｏｌ－１。０．５～４μｇＶ（ｖ）／２５ｍｌ符合比尔定律。用于中草药中痕量钒的侧定，结果满意。     

Liquid-Liquid Extraction of Antimony (III) with Mesityl Oxide

Abstract

Mesityl oxide [(CH₃)₂C[dbnd]CHCOCH₃] was used for the liquid-liquid extraction of antimony. It can be quantitatively extracted from 3 M hydrochloric acid within 10 sec of equilibration with 15 ml of mesityl oxide. The metal from the organic phase was stripped with 10 ml of water and was determined photometrically as its iodide complex at 425 mm. The probable composition of the extractable species at 3 M hydrochloric acid was either SbCl₃ · 3MeO or [HSbCl⁴ (MeO)₃] where MeO is mesityl oxide. The method is simple, rapid, and selective, as it was possible to separate antimony from a large number of elements which are associated with it in alloys and minerals. The method is applicable for the analysis of antimony in solder. The standard deviation is ± 1%.     

二(2-乙基己基)磷酸钠离子交换萃取氨基葡萄糖盐酸盐的研究

氨基葡萄糖盐酸盐极性大,传统物理萃取方法分离效果不理想,今采用离子交换萃取方法用二(2-乙基己基)磷酸钠萃取氨基葡萄糖盐酸盐溶液。测定了氨基葡萄糖盐酸盐初始浓度、萃取温度、萃取剂初始浓度、以及pH值对分配系数的影响。结果表明,在其他实验条件相同的情况下,分配系数随温度变化不明显,随二(2-乙基己基)磷酸钠初始浓度增加而增大,随氨基葡萄糖盐酸盐初始浓度增加而减少,随pH值增加先增大后减小;氨基葡萄糖盐酸盐低浓度下的分配系数远大于其高浓度下的分配系数;为获得最佳萃取效果,萃取平衡体系要尽量接近中性。建立了分配系数模型,并讨论了四种特殊情况下的分配系数表达式。研究结果为工业用离子交换萃取法分离氨基葡萄糖盐酸盐提供了一定的技术依据。     

二(2-乙基己基)磷酸酯为配体的钼系催化体系催化异戊二烯聚合(英文)

研究了二(2-乙基己基)磷酸酯(简称P)配体对二氯二氧钼/烷基铝(简称Mo/Al)催化体系催化异戊二烯(Ip)聚合规律的影响,考察了P/Mo(摩尔比)对单体转化率的影响,并测定了产物的相对分子质量及其分布,表征了其微观结构。结果表明,在P/Mo为5时催化体系的催化活性最高,单体转化率可达80%以上。在最佳聚合条件,即Al/Mo(摩尔比)为10、Mo/Ip(摩尔比)为4×10-4时,聚异戊二烯(PI)数均分子量为1.29×105,分子量分布指数为3.87,PI的1,4-、1,2-和3,4-结构的摩尔分数分别为54.2%、21.0%和24.8%。     

Solvent Extraction Separation of Chromium(VI), Iron(III), Cobalt(II), and Nickel(II) with Di-n-pentyl Sulfoxide

Abstract

Di-n-pentyl sulfoxide (DPSO) was employed for the solvent extraction separation of some transition metals from hydrochloric acid medium. It was found that chromium(VI) gets extracted at low acid concentrations (3 to 4.5 M), and iron(III) and cobalt(II) only above 5 M HCl. Nickel was not extracted at any of the test conditions. These transition metals were separated from one another by suitable choice of the extraction conditions.     

Preparation of Niobium(V) Oxide with Controlled Dispersity and Morphology

Glass and Ceramics - The effect of the annealing temperature and the chemical history of the precipitate on the morphology and phase composition of Nb2O5 powder was investigated. The precipitate...     

Synergic Extraction of Folic Acid with Di(2-ethylhexyl) Phosphoric Acid and Amberlite LA-2

The influences of extractants concentrations and solvent polarity on the efficiency of folic acid separation by synergic extraction with Amberlite LA-2 and di(2-ethylhexyl) phosphoric acid (D2EHPA) mixture have been analyzed. The results indicated the formation of an interfacial compound which includes one molecule of folic acid and one of D2EHPA, the hydrophobicity of this compound being increased by solvation with Amberlite LA-2 molecules. The number of aminic molecules participating in the interfacial complex formation is controlled by solvent polarity and D2EHPA concentration, decreasing from 3 to 1 with the increase of these two parameters. The results indicated that the most important synergic effect corresponds to the extractants mixture dissolved n-heptane, at low D2EHPA concentration in the organic phase (5 g/l).     

Selective Extraction and Separation of Ce (IV) and Th (IV) from RE(III) in Sulfate Medium using Di(2-ethylhexyl)-N-heptylaminomethylphosphonate

The extraction and separation of Ce(IV) and Th(IV) from trivalent rare earths (RE, including scandium) in sulfate medium using di(2-ethylhexyl)-N-heptylaminomethylphosphonate (DEHAMP, L) were studied. The effects of H₂SO₄ concentration, extractant concentration, and temperature on the metal extraction were investigated systematically. It was found that the extraction of metal ions by DEHAMP decreases in the following order: Ce(IV) > Th(IV) > Sc(III) > other RE(III). A possible extraction mechanism was proposed and the extracted complexes as Ce(SO₄)₂·2L and Th(HSO₄)₂SO₄·L were determined by the slope analysis method. Thermodynamic parameters (ΔH, ΔG, and ΔS) were calculated. The extraction reactions of Ce(IV) and Th(IV) were each exothermic processes. The loaded Ce(IV) and Th(IV) can be stripped efficiently by 3% H₂O₂ and 4 mol/L HCl, respectively. The extraction capacity of 0.63 mol/L DEHAMP is 30.0 g/L CeO₂ and 24.4 g/L ThO₂, respectively. Furthermore, a solvent extraction process to selectively extract and recover cerium and thorium from bastnaesite leaching was proposed, by which the purities of cerium and thorium products reached 97.2% and 96.5% with a yield of 85.4% and 98.8%, respectively.     

Gel-Liquid Extraction and Separation of U(VI), Th(IV), Ce(lll), and Co(ll)

Abstract

The gel-liquid extraction of U(VI), Th(IV), Ce(III), and Co(II) has been investigated in the 0.01 to 2 M HNO₃ range using a gel prepared by swelling styrene divinylbenzene with di-(2-ethylhexyl)phosphoric acid. Obtained results indicate that all of the tested cations can be extracted and that the extraction coefficients increase in the order Ce(III) < Co(II) < Th(IV) < U(VI) and generally decrease with acidity. Under suitable conditions, separation of Th(IV), Ce(III), or Co(II) from U(VI) or of Th(IV) from Ce(III) can be achieved. Kinetic studies indicate that the extraction process is controlled by a progressive shell sorption mechanism.     

Extraction of Vanadium(V) from Mixed Chloride/Thiocyanate Solutions with Two Commercial Solvating Extractants

Studies on the extraction and separation of vanadium(V) from mixed hydrochloric acid/ammonium thiocyanate solution with CYANEX 921 and CYANEX 925 in kerosene were carried out. The effects of various factors affecting the extraction process as well as temperature were investigated. Addition of thiocyanate to the chloride solution was found to enhance markedly the extraction of vanadium. HCl solution efficiently stripped V(V). The number of stages required for extraction and stripping of vanadium ions was determined from the McCabe–Thiele diagram. Based on the obtained results, the separation of V(V) from spent catalyst leach indicates the efficiency of the proposed process.     

Distribution Behavior of Amino Acid by Extraction with Di(2-ethylhexyl) Phosphoric Acid

Abstract

The distribution equilibrium of l-tryptophan (l-Trp) by extraction with di(2-ethylhexyl) phosphoric acid (D2EHPA) dissolved in n-hexane was studied. The effects of L-Trp and D2EHPA concentrations, pH, and ionic strength, particularly of L-Trp loading in the organic phase, on extraction equilibrium were examined in detail. When the amino acid loading ratio (the molar concentration ratio of the equilibrium amino acid in the organic phase to the initial dimeric D2EHPA) was less than 3 × 10^?3, one L-Trp molecule was extracted by forming a complex with four monomeric D2EHPA molecules, and the extraction equilibrium constant (K _e) was determined to be 0.045 dm³/mol. Above this loading ratio the equilibrium formula did not hold, and the apparent equilibrium constant (K _a) increased significantly with increasing loading ratio. The phenomenon was explained by taking into account two parallel reactions in which fewer D2EHPA molecules, two and one respectively, were needed to extract one l-Trp molecule.