摘要:

AbstractGold as cyanoaurate is selectively adsorbed by weak‐base resins from alkaline cyanide liquors containing base metal cyanides, and can be quantitatively eluted with aqueous sodium thiocyanate. Interference from, sulphur‐containing anions, especially thiocyanate, which are present in gold ore leach liquors may be overcome by incorporation of 6–10% of strong‐base groups into the weak‐base resin. Resins containing about equal numbers of strong‐ and weak‐base groups are reasonably selective for nickel and silver, which are normally adsorbed together. They may be eluted with either sodium thiocyanate or sodium nitrate made alkaline with ammonia or sodium cyanide. A possible method for the large‐scale recovery of gold, nickel and silver from pregnant cyanide liquors

ISSN:0021-8871    

DOI:10.1002/jctb.5010080201

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractThe nature of the mixed phosphates present in coatings produced by the action of phosphoric acid on a clean steel surface has been investigated. It has been shown that the coating composition changes with time of exposure to atmospheric oxygen. The role of oxygen in the reaction mechanism is discussed.

ISSN:0021-8871    

DOI:10.1002/jctb.5010080202

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractA study has been made of the nature and size of particles produced during the hydrolysis of solutions from titanium ores, and the effect of calcination of these particles. It is shown that the crystallites obtained by hydrolysis grow within the micelles at 600–700° and that at higher temperatures the crystallites sinter to form pigment particles and appreciable conversion to rutile takes place. The effects of the presence of small amounts of alkali during calcination are examin

ISSN:0021-8871    

DOI:10.1002/jctb.5010080203

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractThe adsorption isotherms at 22° of water vapour for a series of homogeneously deacetylated cellulose acetates have been determined. Plots of the sorption (expressed as molecules of water per repeat unit) at any relative humidity against the degree of substitution (D.S.) were linear in the range D.S. = 0.6–2.6. Extrapolation of these linear plots, which are believed to refer to completely amorphous copolymers, to the ordinates at D.S. = 0 or 3 has yielded estimates of the adsorption isotherms of amorphous cellulose and amorphous cellulose triacetate. The values so obtained for amorphous cellulose are in good agreement at high humidities with estimates derived by other methods, but the ‘copolymer extrapolation technique’ seems to fail for this system at humidities<50%. Typical samples of cellulose triacetate are only 70–90% accessible to wate

ISSN:0021-8871    

DOI:10.1002/jctb.5010080204

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractA study has been made of the adsorption by varieties of silica of a number of aromatic compounds, (chiefly dyes), from aqueous solution.Basic dyes are adsorbed by ion‐exchange in the form of a monolayer of cationic micelles, the amount adsorbed being considerably in excess of that required to cover the surface with a normal monolayer. In the case of methylene blue andpseudocyamine chloride, micellar adsorption is confirmed by spectroscopic examination of the solution before and after adsorption. This form of adsorption is very rapid (complete in a few minutes at room temperature) and is not temperature‐dependent.Two typical anionic (sulphonated azo) dyes, Orange I and II, are also adsorbed, but much more slowly and to a less extent than basic dyes. Orange I is adsorbed probably by hydrogen bonding as a monolayer. Both of these dyes are oriented perpendicularly as single anions, but some micellar adsorption may occur. Orange II has no free phenolic group and is adsorbed probably by accompanying sodium ions themselves adsorbed by ion‐exchange, and its extent of coverage is much less than a monolayer. It is suggested that the low adsorption rates are a result of the difficulty the dye anions have in penetrating to the negatively charged silicon surface.p‐Nitrophenol is adsorbed as a monolayer, probably by hydrogen bonding. There is no clear evidence that forces other than ion‐exchange and hydrogen‐bonding are effective in adsorption of any aromatic compound

ISSN:0021-8871    

DOI:10.1002/jctb.5010080205

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010080209

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractBy application of thermal analysis to a number of organic solids, melting and boiling points of the compounds were satisfactorily obtained and latent heats of fusion of the compounds, based on the extent of the endothermic peak area of the melting reaction, were evaluated. The melting and boiling points were generally correct to =3° and the values for latent heats of fusion, as obtained by the method, showed reasonable agreement with the latent heat of fusion of the compounds where known. One of the attractive features of the method was the convenience of obtaining the temperatures of sublimation, decomposition, elimination of water of crystallization etc., which might be difficult by other methods. The thermal effects observed were characteristic of the compounds and threw a useful light on their constitution

ISSN:0021-8871    

DOI:10.1002/jctb.5010080206

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractA comparison of resistance to deformation of rolled asphalt has been made at 45° using eight mechanical tests. The compositions tested conformed to B.S.594 and the comparison showed that these cover a wide range of stability. Some rich plastic mixtures included in B.S.594, although rejected after mechanical tests, can be used successfully on the road. Dynamic loading tests employing préssures experienced on the road appear to give the best relative assessment of stability for the compositions best suited to conditions in Great Britai

ISSN:0021-8871    

DOI:10.1002/jctb.5010080207

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractAn instrument has been developed for detecting colourless substances in the effluent from a chromatographic column. It operates by continuous measurement of the dielectric constant of the liquid, which in general changes with the composition of the solution. A permanent record of the separation is afforded by means of a pen recorder.

ISSN:0021-8871    

DOI:10.1002/jctb.5010080208

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY