Ion exchange resins selective for the complexation of univalent anions in aqueous solutions
Ion exchange resin macroporous beads for the highly selective extraction of univalent anions from aqueous solutions. A specific example is the removal of dicyanoaurate and dicyanoargentate from cyanide leach solutions and tailings. The beads have a maximum number of ligands specific for the desired univalent anion, while maintaining sufficient separation to minimize binding of polyvalent ions. The beads are prepared using a functionalized monomer with the use of a specifically tuned coordinator. The beads can be used as a sensor for detecting the amount of anions captured when interrogated by an appropriate light source.
1. A method of making a macroporous ion exchange resin polymer bead, the method comprising:
preparing a monodentate ligand selective for a univalent ion;
preparing a copolymerizable organic soluble complex comprising the monodentate ligand, a non-complexing monomer, and a crosslinker; and
suspension polymerizing the complex to form a plurality of macroporous polymer beads each comprising a plurality of the monodentate ligands co-polymerized with the monomer and the crosslinker;
wherein the method is performed without imprinting of the univalent ion.
2. The method of claim 1 wherein the monomer comprises styrene and the crosslinker comprises divinyl benzene.
3. The method of claim 1 wherein the organic soluble complex further comprises a thixotropic agent.
4. The method of claim 1 comprising agitating the organic soluble complex prior to or after adding it to a polymerization reaction vessel.
5. The method of claim 4 wherein agitating the organic soluble complex forms droplets of the monomer.
6. The method of claim 1 wherein the monodentate ligand is cationic.
7. The method of claim 1 wherein the monodentate ligand is specific for a luminescent univalent ion.
8. The method of claim 1 wherein the monodentate ligand is selected from the group consisting of cationic oxygen containing heterocyclics, cationic nitrogen containing heterocyclics, cationic sulfur containing heterocyclics, cationic phosphorous containing heterocyclics, ammonium salts, phosphonium salts, acylinium salts, metallocenium salts, amidinium salts, imminium salts, trityl salts, 4-vinylbenzyl-N,N,N-tripentylammonium, 4-vinylbenzyl-N,N-dimethyl-N-hexylammonium, N,N-dimethyl N-heptylammonium, and 4-vinylbenzyl-N,N-dimethyl-N-decylammonium.
9. The method of claim 1 wherein the univalent ion is selected from the group consisting of monatomic univalent anions, polyatomic univalent anions, halides, fluoride, chloride, bromide, iodide, univalent oxyanions, perbromate, periodate, permanganate, pertechnetate, nitrite, nitrate, perchlorate; perchlorate, cyanide, cyanate, thiocyanate; thiocyanate, organic anions, benzoate, acetate, precious metal cyanide complexes, dicyanoaurate, and dicyanoargentate.
10. The method of claim 1 wherein a number of the monodentate ligands on each bead substantially maximizes a binding capacity of each bead to the univalent ion while maintaining spatial separation to minimize cooperative effects between the monodentate ligands.
11. The method of claim 1 wherein the plurality of beads has an average size between approximately 50 microns and approximately 1.5 mm.
12. The method of claim 11 wherein the plurality of beads has an average size between approximately 300 microns and approximately 1000 microns.