摘要:

The separation possibilities of Pyrex glass membranes at high temperatures have been investigated for the separation of sodium and potassium. A separation factor of 11 was obtained for this separation. The limitations of glass membranes for separation purposes are discussed, particularly for the separation of the alkali metal ions.

ISSN:0037-2366    

DOI:10.1080/00372367208056046

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The chromatographic plate theory is applied to the displacement development on ion exchangers of a band containing a mixture of two very closely related species. When the number of plates of the band P is small and the separation factor α=1 + ϵ is closie to unity so that P, ≪ 1, and if one of the species of the mixture is of a small percentage, then a linear distribution of the concentrations in the band is obtained. In a more general case the distribution's eqution is given. The band is symmetrical only if its initial composition is 50–50. In every other case the plate corresponding to the initial mixture is not the median plate of the band. We have derived a mathematical expression which gives the place of the median in the band. A practical determination of the distribution of species in a steady-state band, when P, ϵ, and the composition of the mixture are known, is given. A limited experimental verification is given for the case of the separation of boron isotopes.

ISSN:0037-2366    

DOI:10.1080/00372367208056047

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

In displacement development of mixture of very closely related species on ion exchange columns, determination of the distance between the band middle and the point of initial composition permits an evaluation of HETP. This is applied to the work of Spedding et al. on the separation of nitrogen isotopes. It is shown that steady-state distribution was not obtained and that classical equation giving displacement length for steady-state conditions does not apply for very closely related species such as isotopes.

ISSN:0037-2366    

DOI:10.1080/00372367208056048

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Concentration-dependent diffusivities of potassium citrate and potassium tartrate in aqueous solution were measured by a miorointerferometrio method for solute concentrations ranging from 0.103 to 0.670 grams solute per ml. Empirical formulas for the diffusivity and an activity coefficient of both solutes are presented as a function of solute concentrations.

ISSN:0037-2366    

DOI:10.1080/00372367208056049

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

New systems are described for the highly efficient solvent extraction of mercury with high-molecular-weight amines from aqueous iodide or bromide solutions. Mercury extracts essentially quantitatively at both the sub-nanogram and macro levels. The quaternary amines are especially attractive because of their ability to extract mercury from alkaline as well as acidic solutions. Regeneration of the amine solvent is readily achieved by stripping the mercury with alkaline solutions of cysteine.

ISSN:0037-2366    

DOI:10.1080/00372367208056050

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Distribution coefficients of Zn(II), Cd(II), Au(III), Hg(II), T1(I), and Tl(III) between cation- and anion-exchangers Amberlite IR-120 and Amberlite IR-400, and aqueous solutions containing nitric or hydrochloric acid and organic solvents have been determined. The organic solvents were methanol, acetone, and tetrahydrofuran. The separation of Hg(II) from Zn(II), Cd(II), Au(III), and Tl(III) has been proposed in mixed solvents with high separation factors. Some of these separations have been actually performed using column method.

ISSN:0037-2366    

DOI:10.1080/00372367208056051

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The resolution function based on the impurity ratio of the smaller of two overlapping peaks has been analytically approximated for the general case (molar ratio m ≠ 1, peak width ratio s ≠ 1) of both symmetric and asymmetric peaks. In principle this allows the computation of the additional column length required for the separation of two arbitrary peaks to the same efficiency as the Gaussian m=s=1 case.

ISSN:0037-2366    

DOI:10.1080/00372367208056052

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

A combination of the nonequilibrium method of Giddings and a statistical moment operator method is used to formulate the stationary phase contributions to the rth statistical moment in nonlinear chromatography. It is shown that these do not differ essentially from those of the mobile phaee.

ISSN:0037-2366    

DOI:10.1080/00372367208056053

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Analytical expressions are presented for calculating the extent of separation of binary gas mixtures achievable in a permeation stage, as well as the required membrane area, when the high- and low-pressure streams in the stage flow either countercurrently or cocurrently to each other. The derivations are similar to those of Oishi et al., but are cast in a form suitable for computer calculations. The results of a parametric study on the separation of oxygen from air are presented for four different flow patterns inside the stage: (a) countercurrent flow, (b) cocurrent flow, (c) cross-flow, and (d) perfect mixing. In the first three cases it is assumed that no mixing occurs on the two sides of the stage (or membrane). The type of flow in the permeation stage can have a significant effect on the degree of separation, but has relatively little effect on the membrane area at low separation factors. Countercurrent flow is the most efficient flow pattern, whereas perfect mixing is the least efficient one, both from the viewpoints of extent of separation and membrane area requirements.

ISSN:0037-2366    

DOI:10.1080/00372367208056054

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

We indicate how successive approximations to the solution of equations of the form

ISSN:0037-2366    

DOI:10.1080/00372367208056055

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor