1294 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
landfill site (2) onsite physical and chemical processing
(3) model includes ash feedstock delivery, preparation, and
staging operations. Inputs to the commercial plant model
were mass and energy balance measurements from the pilot
plant, product purities/yields, and anticipated availability
of coal ash. The envisioned commercial plant has a feed
capacity of 1200 metric tons per day of coal ash to the
physical processing module, and 600 tons per day to the
chemical processing module.
The team is currently working on optimizing the REE
production process, demonstrating production of kilogram
quantities of REE, and scaling-up selected process elements.
CONCLUSIONS
Fly ash stored in landfills and ponds across the United States
is an attractive, abundant domestic resource for the recov-
ery of rare earth elements (REE) and other critical minerals
(CM). Our team successfully executed a multiphase project
that developed and demonstrated pilot plant operations for
production of REE concentrates from coal ash. We con-
structed and operated a sub-scale (0.5 kg/day) micropilot
facility to demonstrate the key physical and chemical pro-
cessing operations, predict yields, and troubleshoot process
bottlenecks.
The group collected coal combustion ash was collected
from two power plants. The ash was physically processed to
remove carbon and potential byproducts at a scale of 0.4
tpd. The team optimized the process to generate selected
ash fractions and maximize the yield of ash suitable for
chemical processing.
The project team designed, constructed and operated
a chemical ash processing plant with a capacity of 0.5 tpd
that developed optimized processes for the production of
REEs and beneficiated ash as valuable byproduct suitable
for cement applications. The team achieved REE purities
in excess of 90% relative content and generated 100 g of
REE concentrate material. The pilot plant data fed the con-
ceptual design of an integrated coal ash processing opera-
tion. This work demonstrated the viability of coal ash as a
potential feedstock for critical REEs.
ACKNOWLEDGMENT
This material is based in part upon work supported by the
U.S. Department of Energy under Award DE-FE0027167.
The research reported in this document/presentation was
performed in part in connection with OTA Agreement
W52P1J2193018 with the U.S. Army (Rock Island).
ARMY DISCLAIMER
The views and conclusions contained in this document/
presentation are those of the authors and should not be
interpreted as presenting the official policies or position,
either expressed or implied, of the U.S. Army or the U.S.
Government unless so designated by other authorized
documents.
Figure 13. Commercial plant conceptual diagram
landfill site (2) onsite physical and chemical processing
(3) model includes ash feedstock delivery, preparation, and
staging operations. Inputs to the commercial plant model
were mass and energy balance measurements from the pilot
plant, product purities/yields, and anticipated availability
of coal ash. The envisioned commercial plant has a feed
capacity of 1200 metric tons per day of coal ash to the
physical processing module, and 600 tons per day to the
chemical processing module.
The team is currently working on optimizing the REE
production process, demonstrating production of kilogram
quantities of REE, and scaling-up selected process elements.
CONCLUSIONS
Fly ash stored in landfills and ponds across the United States
is an attractive, abundant domestic resource for the recov-
ery of rare earth elements (REE) and other critical minerals
(CM). Our team successfully executed a multiphase project
that developed and demonstrated pilot plant operations for
production of REE concentrates from coal ash. We con-
structed and operated a sub-scale (0.5 kg/day) micropilot
facility to demonstrate the key physical and chemical pro-
cessing operations, predict yields, and troubleshoot process
bottlenecks.
The group collected coal combustion ash was collected
from two power plants. The ash was physically processed to
remove carbon and potential byproducts at a scale of 0.4
tpd. The team optimized the process to generate selected
ash fractions and maximize the yield of ash suitable for
chemical processing.
The project team designed, constructed and operated
a chemical ash processing plant with a capacity of 0.5 tpd
that developed optimized processes for the production of
REEs and beneficiated ash as valuable byproduct suitable
for cement applications. The team achieved REE purities
in excess of 90% relative content and generated 100 g of
REE concentrate material. The pilot plant data fed the con-
ceptual design of an integrated coal ash processing opera-
tion. This work demonstrated the viability of coal ash as a
potential feedstock for critical REEs.
ACKNOWLEDGMENT
This material is based in part upon work supported by the
U.S. Department of Energy under Award DE-FE0027167.
The research reported in this document/presentation was
performed in part in connection with OTA Agreement
W52P1J2193018 with the U.S. Army (Rock Island).
ARMY DISCLAIMER
The views and conclusions contained in this document/
presentation are those of the authors and should not be
interpreted as presenting the official policies or position,
either expressed or implied, of the U.S. Army or the U.S.
Government unless so designated by other authorized
documents.
Figure 13. Commercial plant conceptual diagram