Polymer coating for immobilizing soluble ions in a phosphate ceramic product
AssigneeThe United States of America as represented by the United States Department of Energy
InventorsDileep Singh, Arun S. Wagh, Kartikey D. Patel
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Abstract
A polymer coating is applied to the surface of a phosphate ceramic composite to effectively immobilize soluble salt anions encapsulated within the phosphate ceramic composite. The polymer coating is made from ceramic materials, including at least one inorganic metal compound, that wet and adhere to the surface structure of the phosphate ceramic composite, thereby isolating the soluble salt anions from the environment and ensuring long-term integrity of the phosphate ceramic composite.
Claims17
A phosphate ceramic encapsulation system for immobilizing waste, comprising:
- a solid phosphate ceramic waste composite where said composite comprises a waste product which is physically micro-encapsulated within a dense matrix of a phosphate ceramic product and where said solid composite forms a solid body with an external surface area;
- and
- a polymer coating comprised of at least one inorganic metal compound where said polymer coating adheres to said external surface area of said ceramic waste composite isolating said ceramic waste composite from an external environment and is comprised of three main components a binder, a pigment and a solvent.
A process for immobilizing salt waste in a solid phosphate ceramic waste form, comprising the steps of:
- providing a solid phosphate ceramic composite where said composite comprises a salt waste which is physically micro-encapsulated within a dense matrix of a phosphate ceramic product and where said solid composite forms a solid body having an external surface area;
- preparing a polymer coating whose composition is comprised of at least one inorganic metal compound;
- applying the polymer coating to the surface of the solid phosphate ceramic composite;
- allowing the polymer coating to infiltrate a surface structure associated with the external surface area, such that the polymer coating adheres to the surface structure;
- and
- allowing the polymer coating to harden by curing, thereby effectively isolating the salt waste from the environment.
An improved method for immobilizing salt waste within a phosphate ceramic composite, comprising the steps of combining salt waste with a starter oxide to obtain a powder, contacting the powder with a phosphate-containing solution to create phosphates of the oxide in a slurry, mixing the slurry while maintaining the slurry below a predetermined temperature, allowing the slurry to set into a phosphate ceramic composite having a crystalline structure, thereby chemically and physically encapsulating the salt waste within the crystalline structure of the phosphate ceramic composite to form a solid mass, wherein the improvement comprises:
- applying a polymer coating comprised of at least one inorganic metal compound to a surface of the solid phosphate ceramic product;
- allowing the polymer coating to infiltrate the crystalline structure of the surface of the phosphate ceramic composite, such that the polymer coating adheres to the structure;
- and
- allowing the polymer coating to harden by curing, thereby effectively isolating the salt waste from the environment.
Dependencies are inferred from the claim text.