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

A method of increasing the capacity of a foundry sand to absorb organic gases, said foundry sand including an oxidizable carbon source selected from the group consisting of carbon, graphite, and mixtures thereof, comprising mixing the carbon source with a ground ore containing a compound selected from humic acid, a metal salt of humic acid, or mixtures thereof, in weight proportions of 20-95% by weight ground ore to 80-5% by weight carbon source, and heating the mixture to a temperature of at least about 450.degree. F.

A method of increasing the capacity of a foundry sand to absorb organic gases comprising adding to said foundry sand an activated carbonaceous material selected from the group consisting of activated carbon;

• activated graphite;
• and mixture thereof in an amount of about 0.1% to about 20%, based on the dry weight of the foundry sand.

A method of casting molten metal, while decreasing an amount of volatile organic compounds escaping from a casting mold, comprising forming a foundry sand in a foundry sand mold shape, said foundry sand including a sand selected from silica sand, olivine sand, zircon sand, chromite sand, carbon sand, fluid coke sand, or mixtures thereof in an amount of about 70% to about 95% by weight;

• a binder for the sand in an amount of about 1% to about 15% by weight;
• and an activated carbon source selected from the group consisting of activated carbon, activated graphite, and mixtures thereof, in an amount of about 0.1% to about 20%;
• and casting molten metal against the foundry sand mold at a temperature of about 450.degree. F. to about 2300.degree. F.