Patent EA-001349-B1 (EA)
Title: Composite material based on hexacyanoferrates and polymer, method for making it and use
Inventor: LOOS NESKOVIC CHRISTIANE
IPC: B01J39/16
Filed: 1998-07-08
Abstract: 1. A solid composite material based on hexacyanoferrates, fixing polluting minerals, characterized in that it comprises a solid support coated with an anion-exchanging polymer film to which is fixed an insoluble metal hexacyanoferrate composite solid material forming a thin layer. 2. Material as claimed in claim 1, characterized in that the quantity of the fixed metal hexacyanoferrate constitutes from 1 to 10% relative to the mass of the solid support. 3. Material as claimed in claim 1, characterized in that the solid support is selected from silicon dioxide, aluminum oxide, titanium oxide, zirconium oxide, diatomaceous earth, zeolites and glass. 4. Material as claimed in claim 1 to 3, characterized in that it comprises the solid support in the form of particles, fibers, membranes, hollow tube or woven or non-woven tissue. 5. Material as claimed in claim 4, characterized in that it comprises the solid support in the form of particles being from 1 to 500 (m in size. 6. Material as claimed in claim 4 or 5, characterized in that the solid support has a specific surface from 10 to 500 m<2>g. 7. Material as claimed in claim 4 and 5, characterized in that the solid support has an average pore size from 100 to 100 angstrom. 8. Material as claimed in claim 1, characterized in that said anion-exchanging polymeris obtaine from an organic polymer, wherein cationic groups can be added to said organic polymer. 9. Material as claimed in claim 8, characterized in that said organic polymer is selected from polyvinylimidazoles, copolymers of vinylimidazole with, at least one another monomer, and polyethyleneimines. 10. Material as claimed in any claim 1 to 10, characterized in that said metal hexacyanoferrate is selected from hexacyanoferrate of copper, cobalt, zinc and cadmium, hexacyanoferrate of nickel, hexacyanoferrate of iron and a mixture of said hexacyanoferrates. 11. Method for preparing  material as claimed in any claim 1 to 10, characterized in that it comprises the following steps: impregnating the solid support by a solution of the organic polymer to form a film of said organic polymer on said solid support: optionally cross-linking of said polymer using a cross-linking agent; optionally forming of the cationic groupson said optionally cross-linked organic polyme; impregnating solid support, comprising a film of the anion-exchanging polymer, by an aqueous solution of an alkali metal hexacyanoferrate; washing and optionally drying of said solid support coated with an anion-exchanging polymer film, on which said alkali metal hexacyanoferrate is fixed; adding an aqueous solution of a metal salt to said solid support with coating to form a solid composite material, fixing polluting minerals; washing and drying. 12. The method as claimed in claim 11, characterized in that a solution of the organic polymer is a solution in a solvent selected from water, alcohols and the mixtures thereof. 13. The method as claimed in claim 11, characterized in that the cross-linking agent is selected from epichlorhydrine, diglycidylic 1,4-butane diol ether and bis-epoxydes. 14. The method as claimed in claim 11, characterized in that the polymer comprises nitrogen atoms, wherein the cationic groups are formed by quaternization. 15. The method as claimed in claim 11, characterized in that said alkali metal hexacyanoferrate is selected from hexacyanoferrates (II) and (III) of sodium and potassium. 16. The method as claimed in claim 11, characterized in that said impregnation by an aqueous solution of said alkali metal hexacyanoferrate is carried out with pH, controlled by a buffer solution. 17. The method as claimed in claim 11, characterized in that said salt is selected from salt of copper, cobalt, nickel, cadmium zinc and iron. 18. The method as claimed in claim 11, characterized in that an anion of said salt is selected from  nitrates, sulfates, chlorides and acetates. 19. The method as claimed in claim 11, characterized in that said steps of washing are carried out in a buffer solution. 20. The method for fixing at least one polluting mineral, comprising in a solution by contacting said solution with the solid composite material fixing polluting minerals as claimed in any claim 1 to 10. 21. The method as claimed in claim 20, characterized in that said solution is an aqueous solution. 22. The method as claimed in claim 20, characterized in that said solution is a technological liquid or industrial effluents. 23. The method as claimed in claim 20, characterized in that said solution is selected from liquids and effluents derived from the nuclear industry and from installations and activities associated with radionucleids. 24. The method as claimed in claim 20, characterized in that it is carried out continuously. 25. The method as claimed in claim 24, characterized in that said solid composite material fixing polluting minerals is used for filling a column. 26. The method as claimed in claims 20 to 25, characterized in that said polluting mineral is present in a concentration from 0,1 picogramm (0,1 x 10<-12>g.) to 100mg/l. 27. The method as claimed in claims 20 to 26, characterized in that said polluting mineral is a metal or a radioactive isotope of said metal. 28. The method as claimed in claim 27, characterized in that said polluting mineral is selected from  anion complexes, colloids and cations. 29. The method as claimed in claims 20 to 28, characterized in that said polluting mineral is selected from Cs, Co, Ag, Ru, Fe and Tl and the isotopes thereof.