US Government As Represented by the Secretary of the Army

Kent James Hay

Veera M Boddu

Dabir S Viswanath

Tushar K Ghosh

Shaoying Qi

Perlite, particularly, perlite in powdered form, is employed to adsorb metals and metal compounds from fluids, in particular gases at elevated temperature. 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, thus increasing the efficiency of the process. In select embodiments, powdered 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 powdered perlite is provided in an adsorption bed. Fluids containing metals or metal compounds in vapor form are permitted to pass through the adsorption bed until the expanded perlite powder is saturated (exhausted) with the metal and metal compounds adsorbed thereon. The perlite is then replaced, disposing of the exhausted perlite.

Method of treating fluid containing vapor phase metals, vapor phase metal compounds, or both

A system and associated method for removing metal, including metal in vapor form, from high temperature fluid emissions such as may occur at the exhaust of furnaces or thermal treatment equipment. One embodiment is the Integrated Metal Emissions Control System (IMECS&#x2122;) incorporating both a Steel Screen Particulate (SSP) Filter System and a Perlite Based Sorbent (PBS) System. IMECS&#x2122; uses the SSP Filter System, with pore sizes down to one micron, to capture toxic metal particulate materials and the PBS System to capture vapor phase metals using surface-modified perlite. Using the IMECS&#x2122;, EPA-listed heavy metals have been removed from representative high-temperature emissions in field tests to easily meet the NESHAP standards.

Method and system for treating metal-containing fluid emissions

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.

Method for surface treating perlite sorbents for improved adsorbing of vapor phase metals and metal compounds at elevated temperatures

An autonomous pushed liquid recirculation system (APLRS) is installed in a vessel, such as an electroplating tank. It situates around the interior perimeter and adjusts to changes in the level of liquid, maintaining the same location and orientation respective to the liquid's surface. It establishes a current near the surface that pushes liquid across the narrow horizontal dimension of the tank from a front wall to a rear wall. The current serves to push any bubbles resultant from operations within the tank to the rear wall. Over the rear wall is mounted an abbreviated exhaust hood covering only a short width of the surface of the tank along the rear wall. Because the exhaust system has to scavenge only a portion of the surface since all bubbles now burst along the rear wall, a much smaller air handling apparatus may be specified with an attendant savings in energy costs.

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Mahomet, IL, United States of America

Kent James Hay