摘要:

Under a rotating centrifugal force field, foams are created within a long fine coiled tube to carry foam active materials through the solvent trapped in each turn of the coil. Rhodamine B introduced at 1 ppm was almost entirely recovered at 620 ppm. High-speed chromatographic separation is possible with a small amount of sample.

ISSN:0037-2366    

DOI:10.1080/01496397608085314

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Cycling zone separation is a method of operating conventional separation devices that can be applied to a wide variety of separations such as adsorption, chromatography, and extraction. The basic technique developed by Pigford et al. (1) consists of cycling some thermodynamic variable in such a way that a continuously fed mixture is separated. The original work removed all solutes at once and has since been extended to multi-component fractionation by Wankat (2). A tutorial review of cycling zone separation was recently presented by Wankat et al. (3) and includes theoretical analyses and a description of experimental results.

ISSN:0037-2366    

DOI:10.1080/01496397608085315

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Mercury(II) and cadmium(II) were separated from aqueous systems by a number of batch-type precipitate flotation and adsorbing colloid flotation techniques. HgS, CdS, and Cd(OH)2were removed by precipitate flotation; Fe(OH)3, Al(OH)3, FeS, and CuS were used as adsorbing colloids. Sodium lauryl sulfate and hexadecyltrimethylammonium bromide (HTA) were used as collectors. Dependence of separation efficiency on pH and ionic strength was investigated. Floc foam flotation of both metals with CuS and HTA was found to be quite effective, resulting in residual Hg(II) levels as low as 5 ppb and residual Cd(II) levels as low as 20 ppb. Floc foam flotation of Cd(II) with FeS and HTA yielded residual Cd(II) levels as low as 10 ppb.

ISSN:0037-2366    

DOI:10.1080/01496397608085316

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The operation of a continuous flow foam flotation column in the stripping mode is analyzed under steady-state conditions. The effects of diffusive mixing, nonlinear adsorption isotherms, and finite rate of mass transport between the surface and bulk phases are taken into account in the differential equations from which column efficiencies are calculated. Adsorption isotherms are calculated by means of statistical mechanics for systems having coulombic interactions.

ISSN:0037-2366    

DOI:10.1080/01496397608085317

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

An experimental investigation is presented of the continuous, single equilibrium stage foam fractionation of chromate (CrO42-) and of thiosulfate (S2O32-) from 0.4 to 3.0 × 10–4Maqueous solutions. The cationic surfactant, ethyl-hexadecyldimethylammonium bromide (EHDA-Br), is modeled as a soluble ion exchanger, considering the exchange of CrO42-and S2O32-or EHDA-CrO4−and EHDA-S2O2−for Br−. The data indicate that EHDA-CrO4−or EHDA- S2O3−is exchanged with Br−. The selectivity coefficient for chromate is 3.90 and that for thiosulfate is 16.8.

ISSN:0037-2366    

DOI:10.1080/01496397608085318

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The high molecular weight pyridine amine, 2-hexylpyridine, has been studied as a component of solvent extraction systems. Extraction of mineral acids by the compound is described. The ionization constant (pKBH+) has been determined by potentiometric titration and spectrophotometrically. The distribution of Au(III) between solutions of 2-hexylpyridine in benzene and different mineral acid solutions has been investigated as a function of the concentration of the acids, extractant, and salting-out agents. The extraction mechanism and the composition of extracted complexes of Au(III) are discussed. Separation factors of a number of metal ions relative to gold have been reported, and the determination of gold from a number of synthetic and ore samples was made by neutron activation analysis. 2-Hexylpyridine has been shown as a selective extraction reagent for gold. It has been shown that 2-hexylpyridine dissolved in benzene will extract gold efficiently and reversibly from moderate acid chloride, nitrate, and sulfate media, and that among the common anions only neutral chloride exerts a slight depressing effect on extraction when present in high concentration. The presence of ferric iron does not interfere with extraction.

ISSN:0037-2366    

DOI:10.1080/01496397608085319

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

A high-precision gas chromatograph was used in conjunction with a quadrupole mass spectrometer and an on-line computer to study the fractionation of carbon and oxygen isotopes in carbon dioxide on two solid adsorbents and on a variety of liquid phases. For adsorption studies the relative retention is reported as a function of temperature on Porapak Q and silica gel. On the former, α values are on the order of 1.0027 ± 0.0001 (standard deviation) for the carbon isotopes and 1.0011 ± 0.0002 for the oxygen species, while on silica gel the values are 1.0031 ±0.0004 and 1.0050 ± 0.0008, respectively. Differential thermodynamic data have been reported. Using diethanolamine and polyethylene imine columns in gas-liquid chromatography, greater fractionation was found. However, column bleed and decomposition of the liquid phase were serious problems.

ISSN:0037-2366    

DOI:10.1080/01496397608085320

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

A new reagent,N-o-tolyl-o-methoxybenzohydroxamic acid (OTMBHA) is proposed for highly sensitive and selective determination of Mo(VI) by rapid extraction of its yellow complex with isoamyl alcohol and simultaneous Spectrophotometric determination at 350 run. The complex follows Beer's law at this wavelength over the concentration range 0.5 to 10.5 μg/ml, the sensitivity being 0.010 μg of Mo/cm2(ε = 9.1 × 103). A 0.01Mreagent solution in isoamyl alcohol is adequate for complete extraction of molybdenum within 5 min. The method is found to be applicable to separation of molybdenum from many metals which constitute the nuclear fuels and fission products. Molybdenum was determined in steels.

ISSN:0037-2366    

DOI:10.1080/01496397608085321

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Very high rates have been reported for the permeation of acetylene through silicone rubber. Measurements in this laboratory, while consistent with the reported data for the permeation of other gases through silicone rubber, do not confirm the rates reported for acetylene.

ISSN:0037-2366    

DOI:10.1080/01496397608085322

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor