Vermiculite — a Promising Material for High-Temperature Heat Insulators

Vermiculite, a mineral of natural occurrence of the group of hydromicas, when heated to above 300°C, 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 1150°C as replacement for lightweight chamotte components and fibrous heat insulators.