ISSN:0736-6299    

DOI:10.1080/07366298608917849

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0736-6299    

DOI:10.1080/07366298608917850

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The extraction of hafnium(IV ) from aqueous hydrochloric, sulphuric and perchloric acid solutions with 3-hydroxy-2-methyl--1-phenyl-4-pyridone(HX) dissolved in chloroform is described. Perchlorate and thiocyanate ions show a synergistic effect on hafnium extraction with HX. Hafnium can be quantitatively extracted with HX from more acidic solutions and with less excess of HX if the extraction is carried out from a hydrochloric, sulphuric or perchloric acid solution containing an excess of perchlorate or thiocyanate ions. A mixed Hf-NCS-HX complex is more stable than a mixed Hf-ClO4-HX complex and thiocyanate ions show a stronger synergistic effect than perchlorate ions.

ISSN:0736-6299    

DOI:10.1080/07366298608917851

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Equilibrium extraction behavior for a series of representative tervalent lanthanide ions, La, Pr, Eu, and Yb, using chloroform solutions containing halogenated derivatives of 4-acyl-l-phenyl-3-methyl-5-pyrazolone have been studied. The results demonstrate that these lanthanides are extracted as simple chelates, LnL⊂3⊂. The equilibrium constants of these extraction reactions have been calculated. The relationships between the acid dissociation constants, K⊂a⊂, determined by a two-phase titration method, distribution constants, K⊂DR⊂, and the extraction equilibrium constants, K⊂ex⊂, discussed.

ISSN:0736-6299    

DOI:10.1080/07366298608917852

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Extraction of Am ( III), Pu( IV), U( VI) from nitric acid solutions by dialkyl ( aryl) [ dialkylcarbamoylmethyl] phosphine oxides of different structures has been studied.

ISSN:0736-6299    

DOI:10.1080/07366298608917853

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The synergism in the extraction of Sr⊃ +⊃ from 0.5M Sr(NO⊂3⊂) ⊂2⊂ by 0.05M dicyclohexano-18-crown-6 (DC18C6) + 0.1M Versatic 1519 (abbreviated v-acid or RCOOH, a neo carboxylic acid) in CCl⊂4⊂ has been found to stem from a strong 1:1 interaction between DC18C6 and Sr⊃2+ ⊃ However, both nitrate and carboxylate can function as the anion for the (DC18C6)Sr⊃2+⊃ moiety. At aqueous conditions corresponding to less than complete loading (i.e., [Sr⊃2+⊃[ org < 0.05M for pH < 11.7), (DC18C6)Sr(NO⊂3;)⊂2⊂ precipitates as a solid. As the pH is raised in the interval 7 < pH < 11.7 to deprotonate the V-acid, the precipitate (DC18C6)Sr(NO⊂3⊂) ⊂2⊂ becomes solubilized first with probable formation of a mixed-anion complex and finally with quantitative (0.05M) formation of the monoraeric complex (DC18C6)Sr(OOCR) ⊂2⊂ H⊂2⊂O at pH = 11.7 as confirmed by viscometric titration of 0.05M DC18C6 in wet CCl⊂4⊂ with Sr(OOCR) ⊂2⊂, Karl-Fischer titrations, vapor-phase osmometry, and IR spectrophotometry.

ISSN:0736-6299    

DOI:10.1080/07366298608917854

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The solvent extraction of Pr(IIl),Gd(III) and Yb (III) with 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-one (PMBP,HP) and with mixtures of PMBP and 1-(2-pyridyl-azo)-2-naphtol(PAN,S) in-CCI⊂4⊂,C⊂6⊂H⊂6⊂ and CHCI⊂3⊂, has been studied..The composition of the extracted complexes has been determined as LnP⊂3⊂.HP and LnP⊂3⊂.S(Ln=Pr,Gd and Yb) The values of the equilibrium constants have been calculated.Weak synergistic effects were found when the metals were extracted with mixtures of the extractants

ISSN:0736-6299    

DOI:10.1080/07366298608917855

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

These results are compared with those obtained with Cl−and (C1−,ClO4−) aqueous media. They are to a great extent explained by taking into account the complexing of In3+by aqueous inorganic anions, the lipophilicity of the diverse species and the anionic exchanges in the B+X−ion pairs.

ISSN:0736-6299    

DOI:10.1080/07366298608917856

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Partial oxidation of manganese(II) and Partial reduction of manganese(III) in acetylacetonate complexes occured in liqudd-liquid systems containing carbon tetrachloride and an aqueous sodium perchlorate solution buffered by sodium hydrogenecarbonate solution equilibrium was assumed to be established after a two phase agitation for several days. Howeve, when the manganese(II) complex was dissolved in air-saturated nonpolar organic solvents such as carbon tetrachloride benzene, and chloroform, it was quantitatively oxidized to the trivalent complex within one hour and the rate was dependent on both the oxygen and ligand. The rate was lower when the solvent was polar and also when an adduct-forming ligand with the bis-chelate such as trioctylphosphine oxide was added into carbon tetrachloride.

ISSN:0736-6299    

DOI:10.1080/07366298608917857

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The application of the Rotating Diffusion Cell (RDC) to the study of solvent extraction kinetics has been described. In the RDC the two phases are brought into contact at the surface of a membrane filter. The filter la rotated on a cylinder, establishing well defined rotating disk hydrodynamics on either side of the filter surface- It is therefore possible to characterize precisely the diffusional processes of the reactant and product species on the aqueous and organic sides of the interface. The area of interfacial contact may be varied without affecting the diffusional processes. It is the characterization of the diffusional processes and the ability to vary the area of interfacial contact which makes this technique very useful in solvent extraction kinetic studies. A few experiments from the cobalt-HEHEHP system have been described to illustrate the use of the RDC.

ISSN:0736-6299    

DOI:10.1080/07366298608917858

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor