Mineral desiccants variably referred to as Montmorillolite, Bentonite or Clays are made from naturally occurring clays that are activated through drying.
Clay is inexpensive and reasonably effective within normal temperature range, but abruptly loses its absorbing capability at just less than 50C. They can be regenerated by drying them slowly at about 65C.
Mineral desiccants are not suitable for use in an environment where the temperature may exceed 50C even temporarily.
Mineral desiccants have a fairly high adsorption rate at low humidity levels, but are much slower than e.g. Silica Gel at higher levels of humidity.
Mineral desiccants are not suitable as a container desiccant, but are good for use in packages where the risk of high temperature is small.
