Method of nonhazardous removal of paint containing heavy metals and coating preparation for performing the same
AssigneeRMT, Inc.
InventorsRobert R. Stanforth, Paul V. Knopp
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Abstract
The present invention involves a method of removing paint containing heavy metal from a surface without the production of hazardous wastes. Specifically, this method involves applying a coating preparation to the heavy metal containing paint prior to its removal from its surface. The preparation contains lead reactive chemicals such as phosphates, metal sulfides and organic sulfides. The preparation may also contain buffers such as magnesium oxide and magnesium hydroxide. These chemicals react with the heavy metals rendering them nonhazardous. The invention also involves the coating preparation itself.
Claims2
A coating preparation which when applied to paint containing heavy metal renders said paint nonhazardous wherein said coating preparation comprises about 5% to about 50% by weight of a phosphate compound selected from the group consisting of triple super phosphate, calcium phosphate, single super phosphate, trisodium phosphate and phosphoric acid;
- about 5% to about 30% by weight of a buffering compound;
- and a carrier for said phosphate compound which enables a layer of said phosphate compound to remain on the surface of said paint for a sufficient time to react with said heavy metal to form a stable nonhazardous heavy metal-phosphate compound.
Dependencies are inferred from the claim text.