Recovery of Rare Earth Elements (REES) from Coal Ash with a Closed Loop Leaching Process


Battelle’s ADP Reactor with Acid Recirculation Tank
Battelle’s ADP Reactor with Acid Recirculation Tank
Battelle Memorial Institute
Website:  Battelle Memorial Institute
Award Number:  FE0027012
Project Duration:  03/01/2016 – 08/31/2017
Total Award Value:  $900,014
DOE Share:  $710,000
Performer Share:  $190,014
Technology Area:  Rare Earth Recovery
Key Technology:  Separation Technologies
Location:  Columbus, Ohio

Project Description

Battelle with support from its partners will validate the economic viability of Battelle’s patented closed-loop Acid Digestion Process (ADP) for recovering REEs from coal ash. This will be accomplished by selecting coal sources with the potential to provide REE concentrations above 300 parts per million by weight, collecting characterization data for coal ash samples generated via three different methods, and performing a techno-economic analysis for the use of the ADP in REE extraction. Three sources of coal ash will be targeted for evaluation in this project: (1) coal ash from power generation stations, to include fly ash and/or bottom ash; (2) ash generated in a lower-temperature ashing process; and (3) residual ash from Battelle’s coal liquefaction process. Thus making use of residual ash from coal liquefaction processes directly leverages work currently being conducted by Battelle for DOE NETL in response to DE-FOA-0000981 entitled “Greenhouse Gas Emissions Reductions Research and Development Leading to Cost-Competitive Coal-to-Liquids Based Jet Fuel Production.” 

Project Benefits

Battelle’s Acid Digestion Process has the potential to concentrate the REEs in coal ashes to a product of greater than 2% REEs by mass, while recovering greater than 90% of the nitric acid used and improving the pozzolanic activity of the ash by-product. The proposed technology offers a breakthrough for the economic recovery of REEs from coal products on several levels.  First, the closed loop process is not expected to generate a significant waste stream, as the process chemicals and emissions are recycled within the process. Second, the process produces a concentrated solid form of rare earth oxides for easy delivery to a REE purification facility. Third, Battelle’s process will identify coal sources expected to have higher availability of REE, thus allowing much higher recoveries of the rare earths, improving the concentration of the product and reducing the cost of the processing operation per ton of recovered REEs. 

Contact Information

Federal Project Manager 
Richard Dunst:
Technology Manager 
Mary Anne Alvin:
Principal Investigator 
Rick Peterson:

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