摘要:

AbstractWhen phosphate rock is dissolved in nitric acid, phosphoric acid and uranium can be selectively extracted by tertiary amyl alcohol; other impurities including the lanthanides remain in the aqueous phase. Uranium can be recovered from the alcohol phase by selective stripping and the lanthanides from the raffinate by extraction with tributyl phosphate.

ISSN:0268-2575    

DOI:10.1002/jctb.280360102

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe electrolysis of simple sugar solutions, containing 0.5% NaCl or Na2SO4, using lead dioxide‐coated titanium mesh anodes in a simple electroflotation cell indicated that electrode corrosion and dissolution of polluting Pb2+ions from the electrode material were negligible even after prolonged use; the sugars were concomitantly electrooxidised at such anodes. The rate of electrooxidation followed linear removal kinetics and the relative ease of electrochemical destruction was in the order sucrose>maltose∼glucose. Such oxidation processes represent added advantages in the use of these electrodes in electrochemical treatment of effluent containing the sugars. Cyclic voltammetric analysis of the glucose solution indicated that oxygen evolution on the lead dioxide‐titanium anode appeared to be promoted by the presence of the sugar. A much more detailed study is required to give further insight into the mechanism of the anodic oxidation of these comp

ISSN:0268-2575    

DOI:10.1002/jctb.280360103

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractA single stage mixer—settler was used to investigate the effect of surfactant on the mass transfer rate in the system water—HNO3—30 vol.% TBP/dodecane. The interfacial tension of this system first falls then rises with increasing sodium lauryl sulphate (SLS) concentration. The addition of SLS makes the stage efficiency, which is closely related tokha, the product of the individual mass transfer coefficient of HNO3in the aqueous phase, and average interfacial area per unit volume of mixing chamber, to increase significantly due to an increase in the value ofa.A maximumkhavalue of 0.53 litres−1, a minimum value of interfacial tension, and phase inversion which converted the aqueous phase from continuous to dispersed were observed at around the critical micellar concentration (100 parts 10−6) of SLS in the system of an aqueous to organic phase rat

ISSN:0268-2575    

DOI:10.1002/jctb.280360104

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe paper deals with studies on selective chlorination of iron oxides in Kerala Ilmenite. Optimum conditions were established with a view to developing an autothermal process.

ISSN:0268-2575    

DOI:10.1002/jctb.280360105

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThis paper summarises our findings on the properties and cation exchange behaviour of a new silica‐based dipotassium trizinc hexacyanoferrate (II) (DTH) prepared under varying conditions of precipitation which possesses good ion‐exchange properties. The product is characterised by i.r. spectra, thermal decomposition, X‐ray diffractogram and its ion‐exchange properties have been studied under different conditions. The separation of Rb+and Cs+is de

ISSN:0268-2575    

DOI:10.1002/jctb.280360106

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractSynthesis of vanillin and 4‐hydroxybenzaldehyde from guaiacol and phenol, respectively, was investigated. The condensation of guaiacol and phenol with glyoxylic acid in an aqueous alkaline medium resulted in the formation of 3‐methoxy‐4‐hydroxymandelic and 4‐hydroxymandelic acid respectively. A process version for the condensation of the phenol with glyoxylic acid, wherein it was found advisable to add an aqueous solution of glyoxylic acid and part of alkali to a batch of the phenol in aqueous alkali, was found to give 77% yield of the mandelic acid based on glyoxylic acid. The oxidation of the mandelic acid could be more suitably carried out at 95°C using 0.51 mol of copper (II) hydroxide for every mole of the mandelic acid in a process where air is simultaneously passed. Taking 3‐methoxy‐4‐hydroxymandelic acid as an example, 88% conversion to vanillin could be obtained. The reaction was found to be second order with respect to t

ISSN:0268-2575    

DOI:10.1002/jctb.280360107

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

ISSN:0268-2575    

DOI:10.1002/jctb.280360101

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY