Method for recycling of rare earth and zirconium oxide materials
AssigneeXylon Technical Ceramics, Inc.
InventorsNicholas H. Burlingame, Samuel Burlingame
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Abstract
A method is presented for recovery, in reusable form, of rare earth minerals and zirconia from waste materials containing them. The method includes: mixing an ammonium sulfate powder and a powder containing the oxide waste material; heating the mixture to decompose the waste into a residue; dissolving the residue in water; separating rare earth constituents from the solution; and subsequently using the separated rare earth constituent (salt or solution) as a raw material. Moreover, the reactants used in the recovery may be recovered by appropriate precipitation and concentration operations.
Claims32
A method for the recovery, in reusable form, of rare earth minerals from oxide waste material containing rare earth and zirconia, comprising:
- a. mixing an ammonium sulfate powder with a powder containing the oxide waste material;
- b. firing the mixture at a temperature sufficient to decompose the oxide waste material and thereby produce a residue which is, to a large degree, soluble in an aqueous solution;
- c. dissolving the residue in water to obtain a solution that includes rare earth constituents in salt form;
- and
- d. separating rare earth constituents from the solution using at least one separation method wherein at least one rare earth constituent is suitable for use as a raw material.
A method for the recovery of rare earth minerals from rare earth waste materials, comprising:
- a. mixing an ammonium sulfate powder with a powder containing the rare earth waste material;
- b. firing the mixture at temperatures sufficient to decompose the rare earth waste material and thereby produce a residue, wherein at least a portion of the residue is soluble in aqueous solution;
- c. dissolving the soluble portion of the residue in water to obtain a solution which comprises the rare earth constituents in salt form;
- d. separating rare earth constituents from the solution using at least one separation method, wherein at least one rare earth constituent is suitable for use as a raw material.
A method for the recovery of zirconia from zircon waste materials, comprising:
- a. at least partially fusing and solidifying the zircon waste materials;
- b. mixing an ammonium sulfate powder with a powder containing the zircon waste materials;
- c. firing the mixture at temperatures sufficient to decompose the zircon waste materials and thereby produce a residue, wherein at least a portion of the residue is soluble in aqueous solution;
- d. dissolving the soluble portion of the residue in water to obtain a solution which comprises zirconia in salt form;
- e. filtering out any insoluble components from the solution;
- f. separating the zirconia from the solution using precipitation of hydrous zirconia by adding ammonium hydroxide;
- and
- g. washing and calcining the hydrous zirconia to form zirconium oxide which can be reused as a raw material.
Dependencies are inferred from the claim text.