摘要:

AbstractMethods employed for the analysis of fly ash and high‐temperature bonded deposits for silicon, aluminium, calcium, magnesium and chloride ion are given. These are determined from one solution obtained by fusing a 0·2 g. sample with sodium hydroxide followed by treatment with sulphuric acid and hydrogen peroxide.The effect of certain interfering ions has been determined and a large number of these ions are removed from the test solution, before determination of calcium, magnesium and aluminium, by mercury cathode electrolysis followed by cupferron‐chloroform extraction.Silicon and aluminium are determined colorimetrically, calcium and magnesium by complexometric methods and the chloride ion by potentiometer.Estimates of standard deviation of 0·09% for silica, 0·1% for alumina and 0·05% for calcium oxide and magnesia were obtained. The methods are suitable for batch a

ISSN:0021-8871    

DOI:10.1002/jctb.5010141201

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractRadiochemical exchange experiments (using36C1−) have been conducted on ‘hydrous’ alumina precipitates containing chloride ions. The precipitates have been prepared in two ways:(a)by reacting aluminium chloride and sodium hydroxide under controlled conditions of pH, concentration and flow rate, and(b)by the hydrolysis of aluminium s‐butoxide across a benzene‐water interface, with chloride ions added to the aqueous medium. All precipitates were washed and dried at room temperature and portions of some were heated at a series of temperatures up to 1000°.The radiochemical investigations have revealed that most of the chloride ions held by the precipitates are readily accessible; some of these ions are transferred to the exchange solution and the remainder are available for rapid exchange. Important differences are, however, evident between the two types of precipitate: the fractional surface coverage by the chloride ions, Øc1, calculated from the amount exchanged and the BET surface area, is reasonably constant and close to unityonlyin the case of the class(a)precipitates. It is suggested that the chloride ions in these samples are present in the form of a well‐defined monolayer, but that the chloride ions held by the class(b)precipitates are probably clustered in the pores of the solid. The Øc1 = 1 relation is maintained with heat treatment of the class(a)precipitates up to at least‐60° and is associated with a relatively low degree

ISSN:0021-8871    

DOI:10.1002/jctb.5010141202

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractThe properties of one batch of autoclave calcium sulphate hemihydrate have been determined. A study has been made of the effects of various concentrations of acetic acid, and potassium and calcium acetates on (i) the rate of evolution of heat, (ii) the setting expansion, (iii) the setting time, (iv) the compressive strength, (v) pH and (vi) the crystal morphology of this plaster. A theory of Ridgeet al. has been tested and is discussed.It has been shown that the three additives have some similarities in their effects on the kinetics of setting and it is concluded that the acetate ion plays a major role in the observed retardation of setting.

ISSN:0021-8871    

DOI:10.1002/jctb.5010141203

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010141209

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractElectrical volume resistivity techniques have been employed to study the hardening and properties of a polyvinyl chloride‐dibutyl phthalate plastisol. It is shown that resistivity measurements can be employed to follow the hardening of plastisol systems and yield information useful in elucidating the nature of the hardening process. This process appears to occur in two stages. In order to obtain the maximum extent of hardening, it is necessary to conduct the final stage in the hardening process at a temperature above the glass transition temperature of the polymeric component. Plasticised systems exhibit a non‐linear dependence of resistivity vs temperat

ISSN:0021-8871    

DOI:10.1002/jctb.5010141204

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractCalcination of ammonium polyuranate at temperatures between 350 and 600°, with a rate of temperature increase of 1°/min., yielded amorphous UO3having surface area of about 30 m.2/g. More rapid increase of temperature gave mixtures of amorphous UO3+β‐UO3with no reproducible surface area. To obtain pure amorphous UO3, the mixtures were hydrated in water or in steam and then dehydrated. During hydration, the surface area decreased and the decrease continued during subsequent calcination, to give a final surface area between 3 and 5 m

ISSN:0021-8871    

DOI:10.1002/jctb.5010141205

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractThe preparation ofp‐phenylenebis(tetraethylphosphonous diamide), and its conversion to the corresponding diphosphonous and diphosphonic acids, is describe

ISSN:0021-8871    

DOI:10.1002/jctb.5010141206

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractExperimental evidence of competitive interactions between individual adsorbates in dilute aqueous bi‐solute systems are presented. Rates of adsorption and positions of equilibrium for adsorption on porous granular carbon have been investigated. In the cases studied, the rate of adsorption as well as the total quantity of a single solute adsorbed at equilibrium is decreased with increasing concentration in the system of a second adsorbate. Indeed, it has been possible to describe quantitatively, after the Langmuir adsorption model, the competitive effect of each solute upon the total quantity of the other adsorbed at equilibrium. It appears that the competitive forces are quite broad in scope, doubtlessly effective to varying degrees in all multiple‐adsorbate systems. Apparently the effect of one solute on the position of equilibrium attained by another is largely a function of the relative energies of adsorption. Kinetic interactions observed in the experiments cannot be explained entirely on this basis, because rates of uptake in the agitated non‐flow experimental systems were apparently controlled by rates of transport of solute in the capillary‐size pores of the adsorbent. Thus, physical hindrance becomes of importance in interpretation of the observed results. The large dodecylbenzenesulphonate molecule exhibits a markedly greater effect on the rates of uptake of the other adsorbates studied than do they upon that of the

ISSN:0021-8871    

DOI:10.1002/jctb.5010141207

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010141208

出版商:John Wiley&Sons, Ltd    

年代:1964

数据来源: WILEY