Activated carbon foundry sand additives and method of casting metal for reduced voc emissions

摘要

An activated carbon and/or activated graphite foundry sand additive, and method of casting molten metal against a foundry sand containing the additive composition. In another embodiment, the activated carbon and/or activated graphite additive (or portion thereof) is formed in-situ by adding to the foundry sand a humic acid-containing and/or a humic acid salt-containing ore (hereinafter referred to separately or in combination as "humic-containing ore") and low VOC-containing (1 mg/g at 1800 DEG F.) carbon or graphite or admixtures of low VOC-containing carbon and graphite. The combination of low VOC-containing carbon and/or graphite and the humic-containing ore react in-situ when the foundry sand is heated by contact with molten metal, at temperatures of about 450 DEG F. to about 2300 DEG F., particularly in the range of about 600 DEG F. to about 2000 DEG F., to activate the carbon and/or graphite. The carbon and/or graphite, activated in-situ during the molding process, absorb and/or adsorb (sorb) gaseous volatile organic compounds (VOCs) within the mold, so that the VOC gases are held by the in-situ activated carbon and/or graphite to satisfy VOC emissions requirements.