Microencapsulated chelating agents and their use in removing metal ions from aqueous solutions
AssigneeStauffer Chemical Company
InventorHerbert B. Scher
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Abstract
Novel polyurea and urea-formaldehyde microcapsules are disclosed which enclose a chelsating agent selected from .beta.-diketones, 8-hydroxyquinolines and their thiol analogs, and oximes. The microcapsules are capable of removing metal ions from water.
Claims14
A process for the purification of an aqueous solution containing metal ion impurities which comprises contacting said solution with a plurality of microcapsules, each comprising a liquid core material, which is substantially insoluble in water, consisting essentially of a metal ion chelating agent selected from the group consisting of -diketones, 8-hydroxyquinolines, and oximes, enclosed within a solid permeable shell of a material selected from the group consisting of polyurea and ureaformaldehyde resins, wherein said metal ion impurities pass through said shell of said microcapsules and are chelated by said chelating agents, and subsequently separating said microcapsules from said solution.
A method for the retrieval of precious metals which comprises filtering an aqueous solution containing precious metal ions through a plurality of microcapsules, each, comprising a liquid core material, which is substantially insoluble in water, consisting essentially of a chelating agent selected from the group consisting of .beta.-diketones, 8-hydroxyquinolines, and oximes, enclosed within a solid permeable shell of a material selected from the group consisting of polyurea and urea-formaldehyde resins, and subsequently separating said microcapsules from said solution.
Dependencies are inferred from the claim text.