Model Experimental Study on Cs Removal from Clay Minerals by Ion Exchange under Microwave Irradiation

This article reports fundamental studies performed, using vermiculite as a model of clay minerals, doped with non radioactive Cs and heated under irradiation of microwave with addition of various salts in powder state. Among various kinds of chemicals added for exchange reaction, CaCl2 and KCl are shown to be effective for Cs removal, and further mixing of CaCO3 has additional effects. Heating to temperature above 670°C is shown to be effective for their removal, however, the heated features of the specimens differed between the microwave and the electric furnace heating. Microwave absorbability or heating characteristics of vermiculite with and/or without additives are also studied. It was shown that mixing of vermiculite with CaCl2 and KCl can enhance microwave heating better than heating of each (vermiculite, KCl, CaCl2) alone, this tendency was consistent with the results of the permittivity and conductivity measurement. Further addition of CaCO3 enhanced thereaction kinetics, however, deteriorates the microwave heating ability. Graphical abstract

Source: Chemical Engineering and Processing: Process Intensification - January 27, 2017 Category: Chemistry Source Type: research