Vermiculite is a naturally occurring mineral. The chemical composition consists of a complex hydrated aluminum and magnesium silicate. The expanded or exfoliated vermiculite has low bulk density, high refractoriness and low thermal conductivity. Chemical inertness makes vermiculite satisfactory for many types of thermal and acoustic insulations [17]. The chemical formula of vermiculite is (Mg,Ca)0.3–0.45(H2O)n{(Mg,Fe, Al)3(Al,Si)4.O10(OH)2} [18].