The Journal of the Society of Chemical Industry Japan
The foam separation process which separates solutes from solutions by the differences in surface activity is available for the removal and recovery of solutes from dilute solutions. This paper reports an experimental investigation on the continuous foam fractionation of two dilute solutions of a surface active agent and metallic ion. The distribution coefficients for both the dodecyl benzene sulfate (DBS) and the zinc ion with DBS between the interface and bulk of solution under the condition
... foaming equilibrium were measured by use of the foam column in which the foam drainage was negligible. The effects of the operating variables on the enrichment ratio for DBS and zinc ions were determined in the column, 32-73.7 cm in foaming height. Also, an equation to calculate the number of transfer unit (NTU) for the foam separation was derived on the basis of the distribution coefficient, and the values of NTU were calculated from the experimettal results. Empirical equations for the height of transfer unit (HTU) involving the gas velocity and the liquid concentration were obtained. Authors have previously discussed the volume fraction of thickener under extremely high shear rate at room temperature. In practice, in ball and roller bearings frictional heating occurs and temperature of greases supplied amounts to about 10-70°C depending upon atomosphere. Hence this paper discusses the grease flow properties in the temperature range of 10-70°C. (1) The Sisko equation va=-77",-F (va : apparent viscosity, : ultimate viscosity, b, n : constants, : shear rate) was valid even in the temperature range of 10-70°C. (2) log voc, vs 11T and log b vs 11T were linear where T is absolute temperature. (3) rico/no (i70 : base oil viscosity)-temperature relation was dependent on the nature of thickener and base oil. (4) log va, vs 11T was linear. Activation energy obtained from this relation was 1-9 kcal/mol. Activation energy inclined to become larger with increasing shear rate. The mechanochemical effects of cadmium series pigments were studied by X-ray diffraction method. Besides, changes in color and some physicochemical properties were also investigated. Samples used in this study were a-and 8-type polymorphs of CdS and 3CdS•ZnS solid solution. Both (a and 8) types of each sample become disordered in the crystal structure by grinding, and then their X-ray diffraction patterns are nearly identical beyond certain stage of the treatment. In the early stage of grinding, crystallite dimension decreased and the lattice distortion increased remarkably, and finally they attain nearly constant values. The colors of each specimen change to dark reddish in the course of grinding. Both the lattice distortion and the color are recovered in the same way by the proper heat treatment. Therefore, it is ascertained that the color change should correspond to the lattice distortion. The pressure effect is definite in the color-change, and it seems that the static pressure affects the surface fine structure of cadmium series pigment samples used in this experiment.