Purification of coal and fly ash by ionic liquids

Patent metadata

Field	Value
Publication number	US-2016222532-A1
Application number	US-201615013016-A
Country	US
Kind code	A1
Filing date	Feb 2, 2016
Priority date	Feb 2, 2015
Publication date	Aug 4, 2016
Grant date	—

Abstract

A method for recovering heavy metals and rare earth elements from fly ash, coal ash, and unrefined mineral ores containing rare earth metals using an ionic liquid and an organic acid to solubilize the metals. The solubilized components are removed from the ionic liquid by electrochemical deposition. The heavy metals and rare earth elements are deposited onto an electrode, and then purified via electrochemical processing.

First claim

1 . A method to recover heavy metals and rare earth elements from coal and fly ash, comprising:
mixing an ionic liquid with an organic acid; adding coal ash, fly ash, or a combination thereof to the ionic liquid and organic acid mixture to form a slurry, wherein the coal ash, fly ash, or combination thereof comprises metals and rare earth elements; stirring the slurry; depositing the metals onto an electrode using electrodeposition; and filtering the slurry to remove any solid material.

2 . The method of claim 1 , wherein the ionic liquid comprises one of the following structures:

where R is an alkyl group or a hydrogen or a halide and X is N or P.

3 . The method of claim 1 , wherein the ionic liquid comprises 1-methyl-3-ethyl-midazolium trifluoroacetate.

4 . The method of claim 1 , wherein the ionic liquid comprises tetrafluoroborate, proprionate, or butanate.

5 . The method of claim 1 , wherein the organic acid comprises acetic acid.

6 . The method of claim 1 , wherein the electrode comprises copper.

7 . The method of claim 1 , additionally comprising recovering the ionic liquid.

8 . The method of claim 1 , additionally comprising electrochemically treating the electrode to remove the metals.

9 . The method of claim 1 , wherein the radioactivity of the coal ash, fly ash, or combination thereof is reduced by 90% or greater.

Assignees

• Us Gov Sec Navy

Inventors

• Sutto Thomas E

Classifications

• C21B15/00

  Other processes for the manufacture of iron from iron compounds (by electrolysis C25C1/06) · CPC title

• C25C7/02

  Electrodes (consumable anodes for the refining the metals C25C1/00 - C25C5/00); Connections thereof · CPC title

• C22B11/044

  from pyrometallurgical residues, e.g. from ashes, dross, flue dust, mud, skim, slag, sludge · CPC title

• C25C1/22 Primary

  of metals not provided for in groups C25C1/02 - C25C1/20 · CPC title

• C22B7/007

  by acid leaching · CPC title