摘要:

AbstractThe kinetics of the dissolution of uranium dioxide in nitric acid have been investigated over a range of acid concentration from 0·3 to 37·0 molal. A change in the reduction mechanism for nitric acid is indicated at about 16 molal concentration.A proposed mechanism for the initial rate period of dissolution is consistent with experimental results and with the known thermodynamics of the syste

ISSN:0021-8871    

DOI:10.1002/jctb.5010180501

出版商:John Wiley&Sons, Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractIsothermal decomposition of coal compacts was carried out in nitrogen between 200–700°, and weight loss was recorded against time. Surface area changes, measured by nitrogen adsorption, were determined at 300° and 500°. The porous structure of the coal disappeared for a while during the decomposition owing to blocking of the pores by tarry matter. The surface area then increased when this tarry matter was driven

ISSN:0021-8871    

DOI:10.1002/jctb.5010180502

出版商:John Wiley&Sons, Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractThe derivation of the Steinour equation is discussed in detail and the calculation of particle size critically examined. A new method of calculation is introduced which may facilitate the use of hindered settling as an industrial analytical tool.

ISSN:0021-8871    

DOI:10.1002/jctb.5010180503

出版商:John Wiley&Sons, Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractPalladium is completely removed from 5 × 10−5M‐PdCl2solutions using the new technique of precipitate flotation of the second kind, in which no surfactant is used to float precipitates. Recoveries were best at pH 1–2 and were not markedly dependent on temperature. Increase in ionic strength had no deleterious effect, unlike conventional precipitate flotation. Palladium can be completely separated from a 400‐fold excess of nickel, a 100‐fold excess of platinum, iron and cobalt, a 10‐fold excess of gold but not from silver in the presence of chloride ions. Equimolar amounts of palladium, nickel and platinum were completely separated from each other by successive flotations. Photographs taken of the bubbles during flotation showed that, at a flow‐rate of 3.1 litre/hour, a mean surface area of 2.07 metre2passed through the c

ISSN:0021-8871    

DOI:10.1002/jctb.5010180504

出版商:John Wiley&Sons, Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractThis paper presents a general comparison between glass beads and new low‐density ceramic spheres as packing materials for fractional distillation columns. The light‐weight ceramic spheres have higher through‐puts, lower pressure drops, better separating power and higher wettability than glass

ISSN:0021-8871    

DOI:10.1002/jctb.5010180505

出版商:John Wiley&Sons, Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractSulphur dioxide is sorbed by paper and slowly converted to sulphuric acid; the presence of this severely reduces the useful life of the material. The sorption (‘pick‐up’) of sulphur dioxide has been investigated for a representative range of papers for exposures lasting many months at concentrations approaching those found in polluted urban atmospheres.It was found that the relative humidity does not significantly affect the long‐term pick‐up rate and that this rate remains constant for prolonged exposures, being proportional to the square root of the gas phase sulphur dioxide concentration. Rosin size increases markedly the long‐term rate while certain other paper additives, e.g. Turkey Red Oxide and Anatase, have no

ISSN:0021-8871    

DOI:10.1002/jctb.5010180506

出版商:John Wiley&Sons, Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractAn experimental investigation is presented of the rate of foam separation of colloidal ferric oxide from aqueous suspension. A cationic surfactant in initial concentrations of from 0·05 to 0·13 mmole/1 is used with negatively charged ferric oxide at pH 10·8. An anionic surfactant in initial concentrations of from 0·03 to 0·10 mmole/1 is used with positively charged ferric oxide at pH 5·8. The initial concentrations of particulates are 2·38 and 1·67 mmole/1, as trivalent iron. The process involves variable volumes and a consideration of relative rates of adsorption and foam separation. The rates of removal of surfactant are directly proportional to the quantities of surfactant in the residual suspension and are independent of the quantities of particulates. The rates of removal of particles are directly proportional to the surfactant to particulate ratio in the residual suspension and are a power function of the quantity of particulates in the residual suspension. In one case, the initial surfactant concentration is significant. The relations obtained are accurate to about 15% for the surfactant removals and to about 24% for the particulate removals; these are reasonable considering process compl

ISSN:0021-8871    

DOI:10.1002/jctb.5010180507

出版商:John Wiley&Sons, Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractDifferential diffusion coefficients of the systems KClH2O and NH4ClH2O have been measured at 20° by an interferometric technique, over a range of concentration up to saturation. Integral diffusivities have been calculated from these differential coefficients, and it is shown that the former are the preferred quantities to use in the standard mass transfer correlat

ISSN:0021-8871    

DOI:10.1002/jctb.5010180508

出版商:John Wiley&Sons, Ltd    

年代:1968

数据来源: WILEY