ISSN:0021-8871    

DOI:10.1002/jctb.5010130107

出版商:John Wiley&Sons, Ltd    

年代:1963

数据来源: WILEY

摘要:

AbstractA technique is described for the continuous extraction of samarium or ytterbium from rare earth concentrates. Extraction is carried out in a packed column by passing a solution of a lanthanon concentrate countercurrent to a dilute sodium amalgam. A samarium or ytterbium amalgam is formed which flows to a second column, where the rare earth is stripped from the amalgam with hydrochloric acid.Factors controlling the efficiency of the process are discussed.

ISSN:0021-8871    

DOI:10.1002/jctb.5010130102

出版商:John Wiley&Sons, Ltd    

年代:1963

数据来源: WILEY

摘要:

AbstractAn automatic gas‐liquid chromatographic apparatus used in heterogeneous kinetic studies is described. Details of the gas sampling device, the detector and the amplifier are given and the reproducibility and sensitivity of the apparatus demonstrated. The apparatus cost is low compared with that of commercial equivalent

ISSN:0021-8871    

DOI:10.1002/jctb.5010130103

出版商:John Wiley&Sons, Ltd    

年代:1963

数据来源: WILEY

摘要:

AbstractInfra‐red absorption spectra, differential thermal and differential thermogravimetric curves, and some newX‐ray diffraction data are presented for synthetic or natural specimens of variscite, metavariscite, strengite, phosphosiderite, barrandite, leucophosphites, taranakites, wavellite and synthetic phosphates of composition KAl2(PO4)2(OH),2H2O, H8(NH4,K)Fe3(PO4)6, 6H2O and H4CaFe2(PO4)4, 5H2O. Infra‐red spectra of berlinite, phosphotridymite and two other anhydrous forms of A1PO4are also given. The infra‐red spectra show that variscite and metavariscite have the structure A1PO4, 2H2O and not A1(OH)2, H2PO4, and serve to indicate the porportion of A1/Fe in the barrandites (Fe, A1)PO4, 2H2O. Leucophosphite, KF2(PO4)2(OH), 2H2O is shown to dehydrate reversibly to a monohydrate and then to an anhydrous product still containing the hydroxy

ISSN:0021-8871    

DOI:10.1002/jctb.5010130104

出版商:John Wiley&Sons, Ltd    

年代:1963

数据来源: WILEY

摘要:

AbstractThe sizes of crystals on aluminium oxide films formed by exposing commercial aluminium (2S) and two nickel‐ and iron‐containing alloys to pure water at high temperature were determined by measuring and counting crystals on electron micrographs of surface replicas. The mean crystal size was determined for eight different times at five temperatures over the range 150–350°. The increase in crystal size followed a law of the typeD= Ainand the values ofnfound were in the range 0.18–0.26. The size distributions for various times at 300° and for various temperatures after 7 h. of exposure are

ISSN:0021-8871    

DOI:10.1002/jctb.5010130105

出版商:John Wiley&Sons, Ltd    

年代:1963

数据来源: WILEY

摘要:

AbstractThe dissolution process for sintered uranium dioxide into nitric acid falls into two regimes of behaviour which depend on the overall transfer rate. The critical dissolution rate is approximately 8 mg. cm.−2min−1, its precise value depending upon the solvent composition. Below this critical value there is a large degree of chemical kinetic control, the dissolution rate being proportional to the cube of nitric acid concentration, the experimental activation energy being 15 kcal. mole−1. Above the critical value the process appears to be controlled by the diffusion of a nitric acid species as the transfer rate is directly proportional to acid concentration with an activation energy of about 4 kcal. mole−1.In addition, the reaction is autocatalysed by the nitrite product so that forced convection can reduce rates by a factor of four times, and nitrite neutralisers can reduce them by a factor of one hundred times.To a first approximation the dissolution rate depends simply on the total nitrate concentration although polyvalent nitrates and, in particular, ferric nitrate, tend to accelerate the r

ISSN:0021-8871    

DOI:10.1002/jctb.5010130106

出版商:John Wiley&Sons, Ltd    

年代:1963

数据来源: WILEY