Vermiculite - A promising material for high-temperature heat insulators

Vermiculite, a mineral of natural occurrence of the group of hydromicas, when heated to above 300degreesC, expands to become a highly efficient heat-insulating material. The expanded vermiculite, owing to its unique properties - low bulk density, low heat conductivity, relatively high melting point, chemical inertness, endurance, and environmental safety - can be used as a filler for heat-insulating materials. Heat insulators based on expanded vermiculite can be used in thermal power units with the hot-wall temperature not exceeding 1150degreesC as replacement for lightweight chamotte components and fibrous heat insulators.