International Classification:
C02F 142
Abstract:
Mineral aluminosilicates enhanced as ion-exchange media for separating diverse ionic materials are provided by dry heating. A hydrated mineral alumino-silicate is irreversibly dehydrated in part, to improve the ratio of its affinity for preferred ions, relative to non-preferred ions, even though doing so reduces its affinity for both types of ions. Such dehydration is accomplished by heating the aluminosilicate until a temperature is reached at which its affinity for non-preferred cations is reduced enough that the ratio of its affinity for preferred ions to its affinity for non-preferred ions is greatly increased. Such aluminosilicates may be zeolites, such as clinoptilolite, or layered clays, such as vermiculite or smectite. 850. degree. C. is an example of such temperature.