Title: Vermiculite
CAS Registry Number: 1318-00-9
Additional Names: Hydrated magnesium-aluminum-iron silicate
Literature References: Typical analysis of Montana vermiculite ore: SiO2 38.64%, MgO 22.68%, Al2O3 14.94%, Fe2O3 9.29%, K2O 7.84%, CaO 1.23%, Cr2O3 0.29%, Mn3O4 0.11%, Cl 0.28%.
Properties: Monoclinic crystals, pseudo-hexagonal characteristics. Soft, resilient, glabrous feel. Dissolves in hot concd H2SO4. Has base exchange capacities. Sold as the ore or in "expanded" form. The expanded grades can absorb large quantities of liquids and remain free flowing. The ore is not sol in weak acids or bases, but expanded grades may be attacked. Vermiculites should be classed as montmorillonoids: Rustum Roy, Chem. Eng. News 32, 4842 (1954).
NOTE: A food grade vermiculite is known as Verxite.
Use: As catalyst; loose fill insulation, filler and packing material. |