Abstract: The invention relates to temperature indicating compositions which display temperature dependent color changes. The invention encompasses temperature indicating compositions, materials, devices and methods of their use. The temperature indicating compositions of the invention are clays that can be used to detect temperature and temperature changes at sub-ambient and particularly sub-zero ° C. temperatures. Temperature of a selected environment can be monitored by placing a temperature-sensitive composition comprising the clay material of this invention in contact with that environment and monitoring the color of the composition.

Abstract: The invention relates to temperature indicating compositions which display temperature dependent color changes. The invention encompasses temperature indicating compositions, materials, devices and methods of their use. The temperature indicating compositions of the invention are clays that can be used to detect temperature and temperature changes at sub-ambient and particularly sub-zero ° C. temperatures. Temperature of a selected environment can be monitored by placing a temperature-sensitive composition comprising the clay material of this invention in contact with that environment and monitoring the color of the composition.

Abstract: A system and method for rapid beneficiation of bentonite clay is disclosed. Beneficiation of the bentonite clay occurs through oxidation of structural ferrous iron. For rapid beneficiation, bentonite clay, preferably ground, is subjected to moist air while the clay is being agitated, preferably by tumbling within a rotating drum, to provide rapid exchange of moisture and oxygen in the air with the bentonite clay aggregates to thereby increase the speed of oxidation of ferrous iron in the bentonite clay. Drying of the thus treated bentonite clay may be then achieved by agitating the clay, again preferably by tumbling within a rotating drum, in the presence of dry air.