Perlite, particularly, perlite in powdered form, is employed to adsorb metals and metal compounds from a fluid flow. In select embodiments, the perlite is treated to expand its surface area and injected into a fluid stream, such as flue gas, held for a specific retention period, and removed for subsequent disposal. In other embodiments the perlite is provided in a fixed adsorption bed and the fluid flow permitted to pass through the bed until the perlite surface is exhausted. The perlite in the fixed bed is then replaced, with the exhausted perlite disposed of as appropriate. Treatment of perlite by boiling with sulfuric acid or suspending in a suspension of sulfur in carbon disulfide has been shown to significantly expand the surface area of perlite.