Thick mica plates refer to Muscovite plates and Phlogopite plates with their thicknesses between 2.0 and 50mm and in most case, they are processed into mica spacers. They have very high heat resistance and excellent flame resistance and also good toughness for easy processing and non-flakingness. Their maximum thickness can be up to 80mm. Thick mica plates are widely used as high-temperature insulating materials on various main-frequency furnaces, intermediate-frequency furnaces, electric arc furnaces, plastic thermoforming machines and other machinery and equipment in such industries as iron and steel, metallurgy and so on.