In my deep dive post into brine mining, I noted that it is not economic to extract rare earth elements (REEs) from oilfield and geothermal brines. Concentrations are not high enough. However, it appears that it can be economic to extract REEs from acid mine drainage (AMD), coal refuse or spoils, and especially clay beds associated with coal beds that are often part of coal spoils, as well as coal itself and coal ash. Some researchers think we can meet half or more of our REE requirements from such sources sometime in the 2030s. Currently, the U.S. imports more than 80% of its needed REEs from China. The U.S. uses about 15,000 tons of REEs per year. That dependence on China is concerning. Contrary to the name, rare earth elements are not rare. However, they do not occur in high concentrations so one could say that concentrated sources of REEs are indeed rare.
Rare Earth Elements (REEs)
According to a
February 2021 paper in the Journal of Geochemical Exploration: “Rare earth
elements (REE) are a group of 17 elements including lanthanides (La-Lu), Sc and
Y. REE are often divided into two groups: light REE (LREE; La to Gd) and heavy
REE (HREE; Tb to Lu, and including Sc and Y). However, there is no consensus on
the definition of HREE and LREE in the scientific community, as in some cases,
LREE and HREE do not include the same elements. In addition, REE are sometimes
divided into three groups: LREE (La to Pm), medium REE (MREE; Sm to Gd) and
HREE (Tb to Lu, and including Sc and Y) or can be defined as critical REE or
non-critical REE (based on market demand), with no specific definition of the
REE considered in each class.” The figure below from the DOE’s NETL shows
the position of REEs and CMs in the periodic table of elements.
China’s Control of REE Processing and Making of REE
Magnets
As mentioned,
we get the vast majority of REEs and REE magnets from China. China controls
about 90% of the world’s REE processing capacity, including purifying REEs to
magnet-grade. China has had in place a ban on technology to extract and
separate REEs, presumably via solvent extraction, which is a process with very
significant negative environmental impacts. Due to these pollution concerns as
well as technical complexity, firms in the “West” have struggled to develop
comparable solvent extraction recovery of REEs. China has also strengthened
export controls on other critical minerals like graphite and the chip-making
mineral gallium and germanium. All of these controls are a ploy to maintain
market dominance. They refer to them as means to protect national security and
public interest.
The latest
Chinese move in late December 2023 is a ban on the export of technology to make
rare earth magnets. According to Reuters this includes “technology to
prepare smarium-cobalt magnets, neodymium-iron-boron magnets and cerium magnets
to its "Catalogue of Technologies Prohibited and Restricted from Export."
“In the list it also banned technology to make rare-earth calcium oxyborate
and production technology for rare earth metals, adding them to a previous ban
on production of rare earth alloy materials.” China is driven to maintain
this control and very strong government subsidization helps them to do so.
Coal Refuse
Coal mining,
processing and combustion produce quite a lot of waste. On the mining and
processing side this includes leftover piles of tailings that includes rock,
shale, slurry, slate, clay, and other materials.
Runoff from such waste can be environmentally
destructive, causing acid mine drainage and leaching iron, manganese, and aluminum
into waterways. For every ton of coal mined there is about 880lbs of waste,
some of which is missed coal. This waste is also flammable and can ignite to
form fires that are difficult to extinguish. In some cases, the waste coal can
be recovered through remining which can make a mining site less
environmentally destructive than before it was remined. Coal combustion waste
includes fly ash, bottom ash, and slag. Every 100 tons of coal that is burned produces
about 85 tons of coal ash. Fly ash is the most voluminous type of combustion waste
(about 80%) and along with bottom ash is stored in very large sludge ponds near
coal-fired power plants. These coal ash impoundments can be a major source of local
pollution of soil, surface water, and groundwater with heavy metals if they
leak or overflow. Some waste coal is reprocessed and burned in waste
coal-burning plants, although they produce more environmental toxins. Fly ash is
used in concrete. The ash is also alkaline and when incorporated into the
acidic coal mining and processing tailings, usually by encapsulating the
tailings in the ash sludge, can reduce the acid mine drainage that it produces.
The average REE
concentration in the world’s coals is about 68.5 ppm. Coal refuse such as coal
ash has enhanced concentrations, with an average REE concentration in coal ash
of 403.5 ppm. That is a higher concentration for coal ash than most AMD. However,
the REEs in coal ash are not as easily liberated as those in AMD since the AMD
has already undergone significant acid leaching and coal refuse may require
calcination, which requires heat and has high CO2 emissions, to enhance and optimize
recovery of REEs.
Extracting REEs and Critical Minerals from Coal Byproducts
and Refuse
A new
potential use for both coal tailings refuse and coal combustion ash is
extraction of REEs. REEs may also be extracted from coal itself and from clay
beds over or under coal beds. Particular kinds of REE-enriched clay beds known
as tonsteins can be the most lucrative for REE extraction. Acid mine drainage
(AMD) is the most voluminous source of potential REEs from coal refuse. The
DOE’s National Energy Technology Lab (NETL) is working with Ohio State
University to develop REE extraction methods and projects. They note the scope
of the resource in the region and elsewhere in the U.S. According to Ohio State
University: “There are 6,000 recorded abandoned mines in Ohio alone, while
4,000 miles of streams in Appalachia and 5,000–10,000 miles of streams in the
western United States have been affected by acid mine drainage; those sites can
serve as a foundation for future production of REEs.” In 2005 the EPA put
AMD affected streams at 12,000 miles. There are different processes that can
extract REEs from coal refuse, which I will describe in the next section.
Essentially,
the acidity of coal refuse produces sulfuric acid in runoff which leaches out
minerals and metals, including REEs and critical minerals. Thus, nature performs
the first step in concentrating these materials. The source of the AMD
containing REEs and critical minerals is the exposure and oxidation of pyrite
(FeS2). A summary of the reactions is as follows:
2 FeS2+7 O2+2 H2O → 2 FeSO4-+2 H2SO4
Pyrite + Oxygen + Water → Ferrous Sulfate + Sulfuric
Acid
Thus, it appears that pyrite, commonly known as ”fool’s
gold,” will perhaps become a source of wealth after all!
In addition to
the REEs, there are critical minerals that can be extracted from AMD and other
coal refuse. These include cobalt which is vital for many types of lithium-ion
batteries in current use. Other critical minerals that can be extracted include
nickel, manganese and aluminum.
Coal refuse is
not the only potential industrial source of REEs/CMs. Residue from uranium
mines and phosphogypsum waste from phosphate fertilizer production are other potential
industrial sources. Bauxite residues and metallurgical slags are other
potential minor sources.
Many universities,
institutes, and other public and private entities are involved in REE/CM research
projects, particularly in the Appalachian region which has high concentrations.
Environmental Impacts of Existing Global REE Mining
and Processing
Environmental
impacts of existing global REE mining and processing projects can vary
considerably based on ore mineral type. A Life Cycle Analysis (LCA) study in
2022 went through the potential environmental impacts of each process in the
workflow from mining through processing of different ore types and determined which
process had the most potential for improvement of environmental impacts. Identified
impacts include those from acidification, eutrophication, and toxicities such
as radioactive dust. Other impacts include those from the energy intensity of
the mining and processing, including the need for heat, and the climate impacts
of those processes. The figure below from the paper shows a simplified version of the chemical
process chain of typical REE mining and processing from mineral ores.
Ion Exchange Chromatography Separation of REEs
In China, most
REE extraction from rock ore is now done by ion exchange. This process also
works for recovering REEs from AMD and other coal refuse. Techniques using ammonium
sulfate, ionic liquids, and eutectic solvent as lixiviants, have been successful.
Ion exchange chromatography does not inherently require the use of solvents for
extraction, although some may be used in limited amounts in some forms of the
process. In ore-based mines there is considerable solvent extraction used, often
in conjunction with ion exchange techniques. Extraction via solvents is not at
all environmentally benign as solvent management is always an issue. Leaching
agents such as hydrochloric acid and hydrofluoric acid can be toxic, often as they have been left as highly acidic ponds. Ion exchange works
simply by attracting positively changed cations and negatively changed anions
as a means of separation.
The Trap-Extract-Precipitate (TEP) Process for REE
Extraction
According to Ohio State University, the
three-stage trap-extract-precipitate (TEP) process for REE extraction is both
very effective at extracting high levels of REEs and environmentally benign. The
TEP process utilizes industrial by-products to trap the REEs and an organic
chelating agent to recover the REEs from the mine drainage. They report: “This approach generates lower
post-extraction waste and minimizes the associated environmental impacts when
compared with other REE extraction techniques. The TEP process retains more
than 99 percent of the REEs and produces solids that contain more than 7 wt.
percent (70,000 ppm) total REEs.”
American Resources’ ReElement Technology: Ligand-Assisted
Chromatographic Separation and Purification Resulting in 99.5% Pure REEs and Critical
Minerals
In late 2020 mining
company American Resources formed a new subsidiary, American Rare Earth, to
extract REEs in Kentucky. Sites in Eastern Kentucky, in Letcher, Knott, and Pike
Counties. The company reported then that “American Rare Earth's initial site
has the ability to produce rare earth oxides having a mix of approximately 20%
neodymium, praseodymium and dysprosium, in addition to healthy levels of cobalt
and lithium, all important elements used in the production of permanent
magnets, electric vehicles (EVs) and other technologies.” Refuse and AMD
from the REE-enriched Dean Coal, or Fire Clay Coal, which is described later in
this post, is to be the main source of the coal-based REEs/CMs. In early 2021,
the company acquired exclusive rights to critical REE separation and
purification technologies from Hasler Ventures LLC and Purdue University. The
environmentally safe method uses ligand-assisted chromatography for the separation
and purification of REEs and CMs from coal, coal refuse, recycled permanent
magnets, and lithium-ion batteries. It can also be used for REE/CM-rich ore
from REE/CM mines. Thus, the method can also be employed as a means of
recycling REEs and CMs from e-waste. Professor Linda Wang at Purdue was the
main developer of the technology and Don Hasler, retired from Purdue, formed
Hasler Ventures, and optioned the technology, and licensed it to American
Resources. The tech is also known as ligand-assisted displacement
chromatography or LAD chromatography. After subsequent development of the
process by Hassler and American Resources, they plan to sublicense the
technology to other companies. The figure below depicts the process.
New Technique Being Developed to Extract REEs from Recycled
Product Components Utilizing Genetically Modified Bacteria
A December 2023
paper in the journal Synthetic Biology describes a new technique using genetically
modified bacteria to extract REEs from recycled product components. The process
uses a modified version of bacterium Vibrio natriegens to extract the
REEs through a process known as biosorption. The study involved testing many different
modified versions of the bacterium. It was found that one of these mutants
boosted extraction by 210% as compared with unmodified V. natriegens. Although
this method is considered to be in the early stages it may one day be able to
replace solvent extraction as the main method for extracting REEs.
The Win-Win-Win of AMD Remediation, REEs/Critical
Minerals Extraction, and Domestic Production
While currently
it is more expensive to extract REEs and critical minerals from AMD than to get
REEs from ore deposits, the process has co-benefits that make it quite
desirable. The costs are also expected to come down and perhaps one day be
competitive with ore deposits. Mining REEs and critical minerals from ore
deposits creates new environmental impacts but getting them from AMD and other
coal refuse helps to remediate past environmental impacts since a necessary
step in the process is water treatment. For countries like the U.S., it also
helps develop strategic domestic supplies of these key resources. One of the
keys to success is to treat the AMD before it gets a chance to enter streams. The
potential additional revenue stream to states for REE/CM extraction from AMD could
be vital since in some states such as West Virginia, mine reclamation funds are
nearing insolvency.
Economics of REE/CM Recovery from Coal Refuse Require
Consideration of Co-Benefits
While there is an
abundance of acid mine drainage that continues to pollute streams and that can
be a feedstock for these materials, it is not currently economical to do so and
it is unlikely to be in the future, even with technological improvements. The
process will continue to require subsidization. However, the co-benefits of
cleaning up streams and reducing dependence on China help to keep the projects going.
Another co-benefit being explored by Ohio University and local environmental
groups is collecting and concentrating iron oxides from AMD to make pigments
for paints, bricks, and tiles. Such projects can provide additional revenue
streams for AMD treatment.
The Mount Storm REE Recovery Project from Acid Mine
Drainage in Northern West Virginia: A Functional Demonstration Project that Can
Potentially Refine AMD from Different Sources
The West Virginia
Water Research Institute (WVWRI), led by Paul Ziemkiewicz, began working with
REE extraction in 2016 and began operating a pilot REE/CM extraction plant at
Mount Storm in Northern West Virginia in 2018, recovering the minerals from AMD.
The project was awarded $5 million in late 2019 to scale up. Ziemkiewicz describes
AMD treatment as an environmental obligation and REE recovery from such
treatment as an opportunity. The scale-up involves partners from the private
sector including Rockwell Automation, L3Eng, SNF Chemicals, Solmax, Endress, and
Hauser as well as the West Virginia DEP. According to WVU Today: “The facility
can treat up to 500 gallons per minute of AMD from an adjacent coal property
while producing nearly two tons per year of REEs and CMs in the form of mixed
oxides. The Mount Storm site is online producing compliant discharge water and,
as of Sept. 2022, the system began production of hydraulic preconcentrate.”
The project received $8 million in new funding from the DOE in the spring of
2023. Ziemkiewicz also points out other advantages of AMD as a feedstock for extraction
projects including the fact that the sites are already permitted. He projects that
5.4% and 7.3% of the global requirements for Terbium and Dysprosium, two of the
most sought-after and critical REEs, can eventually be produced by this
facility alone. Ziemkiewicz also noted “that over 60% of the rare earths in
AMD are neodymium, praseodymium and the heavy REEs that are most utilized in
green energy and defense technologies. That number far surpasses the 12% HREE
produced at typical REE mines.” Thus, it can be discerned that this is a
very important project and others like it can eventually help to develop a
strong domestic REE/CM industry that has less net environmental impact than REE
mines which often result in a significant amount of waste that is low-level radioactive,
with uranium and thorium in the waste. The WVWRI is also involved in a project
to process AMD from a non-coal mine near Butte, Montana, for REE extraction,
working with the DOE and other entities. The AMD from that mine and potentially
several others, will be shipped to what they are calling the Central Refinery in
Mount Storm for processing.
REE Enrichment in Coal Regions
There is
considerable variability of REE enrichment in AMD in different areas and more
specifically in different coals and underclays. There are economic limits to
extractable REEs in particular coals and coal wastes from different coals and
underclays. Cutoffs for REE enrichment lower limits are usually considered to
be somewhere between 250-350ppm. A 2021 study in Ohio coals sampled 234 coal
sites for REE enrichment using portable X-ray fluorescence (XRF), which is
satisfactory for field sampling but less accurate than desktop XRF/XRD analysis.
Some results of the study are shown below where several samples are considered
to have sufficient REE enrichment for extraction. Additionally, different coals,
underclays, and subsequent refuse vary in ratios of different kinds of REEs
(light REEs vs. heavy REEs) and CMs, which can also change the economics of
extracting those resources.
A study published
in May 2020 in Fuel summarized the mechanisms for REE-enrichment in coals: “Four
main genetic modes of REE enrichment in coals have been identified: terrigenous,
tuffaceous, infiltrational, and hydrothermal [6], [7]. REE contents in the
different strata of the same coal deposit may vary significantly.” The
study also noted the most enriched coals in Kentucky, China, and the Russian
Far East.
Tonsteins and Fire Clays: Altered Volcanic Ash
Layers of Kaolinite Clay that are Enriched in REEs: The Fire Clay Coal Seam REE
Play in Eastern Kentucky
Some of the best
resources in coal regions for REE extraction are altered volcanic ash layers deposited
in coal forming swamps. Such altered volcanic ash often yields high-purity kaolinite
clay. These deposits are known as tonstiens and can host very good REE deposits
of high concentration. One of the most prominent and most enriched of these
tonsteins is one deposited within the Fire Clay Coal seam in southeast Kentucky
where REE concentrations as high as 4198 ppm have been recorded. The Fire Clay
tonstein is a kaolinized, airfall volcanic ash bed that was deposited in a
widespread late Carboniferous peat-forming mire. The tonstein in the Dean Coal,
known more commonly as the Fire Clay Coal, is nearly as laterally extensive as
the coal itself but in some places, there is no tonstein but still high REE
concentrations. There, it is thought that the ash was emplaced but not hydrothermally
altered. The source of the volcanic activity that delivered the ash in Middle Pennsylvanian
times is thought to be in the Arkansas region. The emplacement of the Pine
Mountain thrust sheet in later Pennsylvanian times as part of the Alleghenian
orogeny to the south, mostly in Southwest Virginia, is thought to have been the
source for the hydrothermal activity that led to the hydrothermal alteration of
the ash layers.
Another Eastern
Kentucky coal seam, the Manchester seam, also has very high REE concentrations
rivaling those of the Fire Clay seam, with some over 2000 ppm reported in Clay
County, Kentucky. However, this Middle Pennsylvanian coal is not known to have
any volcanic ash or volcanic influence, so for now it is an enigma. Perhaps the
ash layer was more diluted, as some researchers have suggested. However, the
Fire Clay coal and tonstein are consistently REE-enriched and much more laterally
extensive and thus should be considered to be the most prominent REE coal/tonstein
play in Appalachia and probably the U.S.
Source: Lanthanide, yttrium, and zirconium anomalies in the Fire Clay coal bed, Eastern Kentucky. James C Hower, Leslie Ruppert, and Cortland F. Eble. International Journal of Coal Geology 39(s 1–3):141–153. 1999. (PDF) Lanthanide, yttrium, and zirconium anomalies in the Fire Clay coal bed, Eastern Kentucky (researchgate.net)
According to a
May 2020 paper in Fuel: “the flint clay parting of the Fire Clay coal seam
contained 490 ppm of REEs on a whole sample basis, which is much higher than
the other strata of the seam (Hower et al., 1999). A sample collected from the
immediate floor of a coal from the Guxu Coalfield (located in the southeastern
part of Sichuan Province, China) contained as high as 1877 ppm of REEs, which
is nearly an order-of-magnitude higher than the coal strata.” Coals from
the Russian Far East also have high REE concentrations. However, since both
China and Russia are unsatisfactory as suppliers of these needed materials for
geopolitical reasons, countries of the so-called free world are necessarily looking
for their own best sources.
Calcination Improves Leaching Recovery of REEs from Coal
Waste and the Potential of Coal Ash as a Feedstock
Acid leaching,
as occurs in the formation of AMD, is what provides the first step in
concentrating REE’s in AMD. Acid leaching can be improved when treating coal refuse
such as coal ash through calcination so that more REE’s and CMs are recovered.
Calcination involves adding limestone and significant heat (unfortunately both high
CO2-emitting processes) which chemically alters clays and makes insoluble
materials soluble. Thus, while coal ash may have higher concentrations of REEs
than other coal refuse and AMD, the higher emissions from calcination may make
extracting them from the ash less desirable.
A study
published in Fuel in May 2022 showed that calcination improves REE recovery percentages
and offers two mechanisms: “(1) decomposition of difficult-to-dissolve
REE-bearing minerals into soluble forms; and (2) liberation of REE-bearing
minerals encapsulated in clays after calcination due to the dehydration and
disintegration of the layered clay structure.” It was also noted that there
was no direct evidence for these mechanisms. The study involved recovery from
the REE-enriched Fire Clay in Eastern Kentucky and the Western Kentucky No. 13 coal
seam. In the study scanning electron microscopy-energy dispersive X-ray
spectroscopy (SEM-EDS) analysis were used. According to the study’s conclusions
“enhanced REE recovery from the Western Kentucky No. 13 and Fire Clay coal
wastes caused by calcination at 600 °C without adding any additives. Acid
leaching test results showed that after the calcination pretreatment, the
recovery of TREEs from the coal waste of the two different seams increased by
52 and 17 absolute percentage points, respectively.”
Thus, it
appears that calcination will be one key to enhancing recovery from coal refuse.
I would also guess that carbon capture and sequestration during the calcination
process will be proposed as it has been for calcination in the manufacture of
concrete.
Coal ash has
some advantages and disadvantages as a potential feedstock for REEs/CMs. While
concentrations average about 400 ppm globally, in the Southern Appalachian
Basin region they can average 500 ppm. Coal ash is captured in a granular, crushed
state, which can provide easier access to REEs/CMs.
The American
Chemical Society’s Environmental Science Technology published a paper in March
2023 about a new “green” process for REE recovery from coal fly ash (CFA). According
to the paper’s abstract: “This study demonstrates a green system for REE
recovery from Class F and C CFA that consists of three modules: REE leaching
using citrate, REE separation and concentration using oxalate, and zeolite
synthesis using secondary wastes from Modules I and II. In Module I, ∼10
and 60% REEs were leached from the Class F and C CFA samples, respectively,
using citrate at pH 4. In Module II, the addition of oxalate selectively
precipitated and concentrated REEs from the leachate via the formation of
weddellite (CaC2O4·2H2O), while other trace metals remained in solution. In
Module III, zeolite was synthesized using wastes from Modules I and II. This
study is characterized by the successful recovery of REEs and upcycling of
secondary wastes, which addresses both REE recovery and CFA management
challenges.” This multi-step process looks promising for REE recovery from coal
fly ash. A model of the process is shown below.
Other processes for liberating higher percentages of REEs
from coal ash include calcination, as mentioned, and chemical roasting using sodium
hydroxide and other alkaline materials.
U.S. Government Incentives for Domestic Critical
Minerals, Including REEs, Ownership Delineation, and Other Regulatory Concerns
In early August
2021, the bipartisan Rare Earth Manufacturing Production Tax Credit was
introduced by Eric Swalwell (D) and Guy Rosenthaler (R). This would provide a
tax credit for mining and processing of REEs at $20 per kilogram for
domestically produced rare earth magnets. If all component rare earth material
is made or recycled in the U.S, the credit increases to $30 per kg. This was
reintroduced in the House as H.R. 2849, the Rare Earth Magnet Manufacturing
Production Tax Credit Act of 2023 in April 2023:
“This bill allows a new tax credit for the domestic
production of rare earth magnets. The magnets must be manufactured or produced
in the ordinary course of the taxpayer's trade or business. The credit is
disallowed if any component rare earth material used to produce such magnets is
produced in a non-allied foreign nation.”
“The bill defines rare earth magnet as a permanent
magnet comprised of an alloy of neodymium, iron, and boron, or an alloy of
samarium and cobalt, which may also include other material.”
This bill has yet to be enacted and is now considered unlikely
to be enacted as is in the near term.
Peter Cook and
Seaver Wang argue in a recent Breakthrough Institute article that critical minerals
regulation and incentivization need to be updated and regulated separate from
other minerals and materials. They are currently regulated along with other
minerals under the Mineral Leasing Act of 1920 (MLA) and the Materials Act of
1947. They argue for a separate regulatory classification for critical minerals.
They note: “A principal benefit of a separate regulatory classification for
critical minerals is that it would enable land management agencies to
preemptively complete related work that is necessary for permitting new mine
projects. Currently, agencies complete this work much later, after an operator
has already applied to develop a mine. A separate classification would allow
Congress and agencies to design, fund, and staff programs that target areas
with critical minerals resources and proactively complete steps in the
environmental review process, like baseline data collection, ecological
assessments, and cultural resource inventories.” They also advocate for
other common-sense ways to simplify and speed up permitting for CMs. The goal is
for regulatory agencies to have a classification framework for CMs that matches
that of the USGS. There are concerns that a mad rush for domestic CMs would invite
environmental damage. The article mostly addresses concerns with mining CMs
rather than extracting them from existing waste streams, so it is probably not
very relevant to this post. Most REE/CM extraction from these sources is likely
already free to take place without much regulatory red tape as in many cases such
as AMD, there are net environmental benefits to the extraction.
The state of
West Virginia worked on House Bill 4003 from 2021 and it passed the Senate in March
2022. This bill promotes REE/CM extraction from AMD and other coal refuse and clarifies
ownership of extraction projects and profits. Paul Ziemkiewicz, who directs the
West Virginia Water Research Institute, has been instrumental in developing REE/CM
recovery projects in West Virginia and in making suggestions to government
regarding ownership. According to WVU Today:
“HB 4003 would follow through on Ziemkiewicz’s
suggestion to state lawmakers that they clarify who owns the resources
resulting from treated acid mine drainage.”
“Ziemkiewicz has also said rare earth element recovery
could supply financial support for state mine cleanup funding.”
“HB 4003 specifies that all funds received by the
state Department of Environmental Protection from commercial benefit from mine
drainage treatment would go into the agency’s Special Reclamation Water Trust
Fund or a set-aside fund for acid mine drainage.”
Another bill pending in the state, House Bill 4025, offers 5-year
exemptions from severance tax for projects extracting REEs and CMs.
References:
Ohio
State University Researchers Demonstrate REE Recovery Process. U.S. Dept. of
Energy. Office of Fossil Energy and Carbon Management. January 15, 2020.
Ohio State University Researchers
Demonstrate REE Recovery Process | Department of Energy
Recovery
potential of rare earth elements from mining and industrial residues: A review
and cases studies. Sophie Costis, Kristin K. Mueller, Lucie Coudert, Carmen
Mihaela Neculita, Nicolas Reynier, and Jean-Francois Blais. Journal of
Geochemical Exploration. Volume 221, February 2021, 106699. Recovery potential of rare earth
elements from mining and industrial residues: A review and cases studies -
ScienceDirect
In
coal country, a new chance to clean up a toxic legacy. Austyn Gaffney and Dane
Rhys. Washington Post. May 19, 2022. Coal states explore how to recyle
metals and rare earths from mine waste - The Washington Post
Rare
earth elements from waste. Bing Deng, Xin Wang, Duy Xuan Luong, Robert A.
Carter, Zhe Wang, Mason B. Tomson, and James M. Tour. Science Advances. Vol 8,
Issue 6. February 9, 2022. Rare earth elements from waste |
Science Advances
Remining
in Ohio. Ohio Dept. of Natural Resources. Youtube. Bing Videos
Rare
earth elements from coal and coal discard – A review. Orevaoghene
Eterigho-Ikelegbe, Hamza Harrar, and Samson Bada. Minerals Engineering. Volume
173, 1 November 2021, 107187. Rare earth elements from coal and
coal discard – A review - ScienceDirect
Rare
earth element resource evaluation of coal byproducts: A case study from the
Powder River Basin, Wyoming. D.A. Bagdonas, A.J. Enriquez, K.A. Coddington,
D.C. Finnoff, J.F. McLaughlin, M.D. Bazilian, E.H. Phillips, T.L. McLing. Renewable
and Sustainable Energy Reviews. Volume 158, April 2022, 112148. Rare earth element resource
evaluation of coal byproducts: A case study from the Powder River Basin,
Wyoming - ScienceDirect
Qualitative
Rare Earth Element Analysis of Ohio Underclays using Portable X-Ray
Fluorescense. Samuel R.W. Hulett, Franklin L. Fugitt, and Christopher E. Wright.
Ohio Department of Natural Resources, Division of Geological Survey. AAPG_Clay REE_v2 copy (ohiodnr.gov)
Extraction
Kinetics of Rare Earth Elements from Ion-Adsorbed Underclays. Priscilla Prem, Ward
Burgess, Jon Yang, and Circe Verba. Minerals 2023, 13(12), 1503. November 30,
2023. Minerals | Free Full-Text |
Extraction Kinetics of Rare Earth Elements from Ion-Adsorbed Underclays
(mdpi.com)
Rare
earth discoveries mean coal mines could have a key role to play in the energy
transition. Anmar Frangoul. CNBC. November 24, 2023. Rare earth discoveries mean coal
mines could have a key role to play in the energy transition (msn.com)
WVU
researchers earn $8M for rare earth extraction facility, an economic and
environmental game changer. WVU Today. Wednesday, April 5, 2023.
WVU researchers earn $8M for rare
earth extraction facility, an economic and environmental game changer | WVU
Today | West Virginia University
WVU
awarded $5 million to continue rare earth project, build acid mine drainage
treatment facility. WVU Today. Tuesday, October 1, 2019. WVU awarded $5 million to continue
rare earth project, build acid mine drainage treatment facility | WVU Today |
West Virginia University
North
Dakota researchers find cost-effective way to extract rare-earth elements from
coal. Dan Gunderson. MPR News. Grand Forks, N.D. December 8, 2023. North Dakota researchers find
cost-effective way to extract rare-earth elements from coal | MPR News
Aspects
of rare earth element enrichment in Central Appalachian coals. James C. Hower,
Cortland F. Eble, Jason S. Backus, Panpan Xie, Jingjing Liu, Biao Fu, and Madison
M. Hood. Applied Geochemistry. Volume 120, September 2020, 104676. Aspects of rare earth element
enrichment in Central Appalachian coals - ScienceDirect
Characterization
and recovery of rare earth elements and other critical metals (Co, Cr, Li, Mn,
Sr, and V) from the calcination products of a coal refuse sample. Wencai Zhang
and Rick Honaker. Fuel. Volume 267, 1 May 2020, 117236. Characterization and recovery of rare
earth elements and other critical metals (Co, Cr, Li, Mn, Sr, and V) from the
calcination products of a coal refuse sample - ScienceDirect
Lanthanide,
yttrium, and zirconium anomalies in the Fire Clay coal bed, Eastern Kentucky. James
C Hower, Leslie F Ruppert, and Cortland F Eble. International Journal of Coal
Geology. Volume 39, Issues 1–3, March 1999, Pages 141-153. Lanthanide, yttrium, and zirconium
anomalies in the Fire Clay coal bed, Eastern Kentucky - ScienceDirect
Tonstein.
Wikipedia. Tonstein - Wikipedia
Seatearth.
Wikipedia. Seatearth - Wikipedia
The
origin of tonsteins, an overview, and links with seatearths, fireclays and
fragmental clay rocks. D.A. Spears. International Journal of Coal Geology. Volume
94, 1 May 2012, Pages 22-31. The origin of tonsteins, an overview,
and links with seatearths, fireclays and fragmental clay rocks - ScienceDirect
Mineralogy,
Geochemistry, and Genesis of Kaolinitic Claystone Deposits in the Datong
Coalfield, Northern China. Linsong Liu, Qinfu Liu, Thomas Algeo, Hao Zhang,
Yongjie Yang, Gaoyu Peng, Shuai Zhang, Hanlie Hong & Di Liu. Clays and Clay
Minerals. 69, pages68–93 (April 2021). Mineralogy, Geochemistry, and Genesis
of Kaolinitic Claystone Deposits in the Datong Coalfield, Northern China |
Clays and Clay Minerals (springer.com)
A
Study on Removal of Rare Earth Elements from U.S. Coal Byproducts by Ion
Exchange. Peter L. Rozelle, Aditi B. Khadilkar, Nuerxida Pulati, Nari
Soundarrajan, Mark S. Klima, Morgan M. Mosser, Charles E. Miller & Sarma V.
Pisupati. Metallurgical and Materials Transactions E. volume 3, pages6–17 (2016). A Study on Removal of Rare Earth
Elements from U.S. Coal Byproducts by Ion Exchange | Metallurgical and
Materials Transactions E (springer.com)
Rare
Earth and Critical Element Chemistry of the Volcanic Ash-fall Parting in the
Fire Clay Coal, Eastern Kentucky, USA. Jingjing Liu, Shifeng Dai, Debora Berti,
Cortland F. Eble, Mengjun Dong, Yan Gao & James C. Hower. Clays and Clay
Minerals. volume
71, pages309–339 (2023). Rare Earth and Critical Element
Chemistry of the Volcanic Ash-fall Parting in the Fire Clay Coal, Eastern
Kentucky, USA | Clays and Clay Minerals (springer.com)
A
Study on Removal of Rare Earth Elements from U.S. Coal Byproducts by Ion
Exchange. Peter L. Rozelle, Aditi B. Khadilkar, Nuerxida Pulati, Nari Soundarrajan,
Mark S. Klima, Morgan M. Mosser, Charles E. Miller, and Sarma V. Pisapadi. A Study on Removal of Rare Earth
Elements from U.S. Coal Byproducts by Ion Exchange | Metallurgical and
Materials Transactions E (springer.com)
Little
bacterium may make big impact on rare-earth processing. Phys.org. Blaine
Friedlander. December 2023. Little bacterium may make big impact
on rare-earth processing (msn.com)
US
companies work to ramp up domestic rare earth manufacturing. Bret Baier and Amy
Munneke. Fox News. December 6, 2023. US companies work to ramp up domestic
rare earth manufacturing (msn.com)
Recovering
Rare Earth Elements from Coal Mine Drainage Using Industrial Byproducts: Environmental
and Economic Consequences. Marcos M. Miranda, Jeffrey M. Bielicki, Soomin Chun,
and Chin-Min Cheng. Environmental Engineering Science. Vol. 39, No. 9. September
15, 2022. Recovering Rare Earth Elements from
Coal Mine Drainage Using Industrial Byproducts: Environmental and Economic
Consequences | Environmental Engineering Science (liebertpub.com)
Coal
refuse. Wikipedia. Coal refuse - Wikipedia
The
Remarkable Responsibility of Coal Refuse Power. Sonal Patel. Power Magazine. August
2, 2021. The Remarkable Responsibility of Coal
Refuse Power (powermag.com)
Rare
Earth Element Trap-Extract-Precipitate (REE-TEP) Process. The Ohio State
University. Office of Innovation and Economic Development. 2022. Rare Earth Element
Trap-Extract-Precipitate (REE-TEP) Process | Office of Innovation and Economic
Development, The Ohio State University (osu.edu)
From
pollutant to resource: WVU scientists push rare earth element technologies
closer to production. WVU Today, April 21, 2021. From pollutant to resource: WVU
scientists push rare earth element technologies closer to production | WVU
Today | West Virginia University
Rare
earth elements from coal mining could boost Appalachian region. Mark Cutis.
13WOWK. July 25, 2019. Rare earth elements from coal mining
could boost Appalachian region | West Virginia Water Research Institute | West
Virginia University (wvu.edu)
WVU
awarded $5 million to continue rare earth project, build acid mine drainage
treatment facility. WVU. October 2, 2019. WVU awarded $5 million to continue
rare earth project, build acid mine drainage treatment facility | West Virginia
Water Research Institute | West Virginia University
Polluted
Streams May Yield Minerals Critical for High Tech. Steve Baragona. Voice of
America. December 5, 2019. Polluted Streams May Yield Minerals
Critical for High Tech | West Virginia Water Research Institute | West Virginia
University (wvu.edu)
Turning
coal mine drainage into source of rare minerals. Tatyana Woodall. Ohio State
University. Phys.org. January 3, 2023. Turning coal mine drainage into
source of rare minerals (phys.org)
China
bans export of rare earths processing tech over national security. Siyi Liu and
Dominique Patton. Reuters. December 22, 2023. China bans export of rare earths
processing tech over national security | Reuters
Acid
Mine Drainage Treatment Solutions. WesTech. Acid Mine Drainage Solutions for the
Mineral Industry (westech-inc.com)
WVU
partners with Extreme Endeavors to mine rare earth elements from acid mine
drainage. Veronica Ogbe. WDTV. July 13, 2020. WVU partners with Extreme Endeavors
to mine rare earth elements from acid mine drainage | West Virginia Water
Research Institute | West Virginia University
WVU
researchers move rare earth elements technologies closer to production. Tracy
Novak. WVU Energy Institute. October 16, 2020. WVU researchers move rare earth
elements technologies closer to production | West Virginia Water Research
Institute | West Virginia University
From
pollutant to resource: WVU scientists push rare earth element technologies
closer to production. Jake Stump. WVU Today. April 23. 2021. From pollutant to resource: WVU
scientists push rare earth element technologies closer to production | West
Virginia Water Research Institute | West Virginia University
Water
Research Institute director updates WV legislators on rare earth recovery
efforts, urges law clarifying ownership. Mike Tony. Charleston Gazette-Mail.
September 15, 2021. Water Research Institute director
updates WV legislators on rare earth recovery efforts, urges law clarifying
ownership | West Virginia Water Research Institute | West Virginia University
(wvu.edu)
State
lawmakers consider benefits, legal complexity of rare earth elements draft
legislation. Mike Tony. Charleston Gazette-Mail. November 18, 2021. State lawmakers consider benefits,
legal complexity of rare earth elements draft legislation | West Virginia Water
Research Institute | West Virginia University (wvu.edu)
WV
House passes bill clarifying who profits from extracting rare earth elements
from mine drainage. Mike Tony. Charleston Gazette-Mail. February 7, 2022. WV House passes bill clarifying who
profits from extracting rare earth elements from mine drainage | West Virginia
Water Research Institute | West Virginia University (wvu.edu)
WV
Senate passes bill clarifying who profits from extracting rare earth elements
from mine drainage. Mike Tony. Charleston Gazette-Mail. March 11, 2022. WV Senate passes bill clarifying who
profits from extracting rare earth elements from mine drainage | West Virginia
Water Research Institute | West Virginia University (wvu.edu)
Could
Coal Waste Be Used to Make Sustainable Batteries? Eliza Griswold. The New
Yorker. August 26, 2023. Could Coal Waste Be Used to Make
Sustainable Batteries? | West Virginia Water Research Institute | West Virginia
University (wvu.edu)
West
Virginia University From Pollutant to Product. Rockwell Automation. November
10, 2022. West Virginia University From
Pollutant to Product | West Virginia Water Research Institute | West Virginia
University (wvu.edu)
WVU’s
Water Research Institute receives additional $11MM for Rare Earth Research. West
Virginia Water Research Institute. September 13, 2023. WVU’s Water Research Institute
receives additional $11MM for Rare Earth Research | West Virginia Water
Research Institute | West Virginia University
Rare
Earth Elements and Critical Minerals. NETL. 2021. Program-141_0.pdf (doe.gov)
Recovery
of Rare Earth Elements and Critical Materials from Coal and Coal Byproducts: Report
to Congress. May 2022. United States Department of Energy. Report to Congress on Recovery of
Rare Earth Elements and Critical Minerals from Coal and Coal By-Products.pdf
(energy.gov)
Isopach
map and regional correlations of the Fire Clay tonstein, central Appalachian
Basin. William F. Outerbridge. U.S. Geological Survey. Open-File Report 03-351.
2003. Isopach map of the Fire Clay
tonstein, central Appalachian Basin (usgs.gov)
The
Pennsylvanian Fire Clay tonstein of the Appalachian basin—Its distribution,
biostratigraphy, and mineralogy: Discussion and reply. William F. Outerbridge. GSA
Bulletin (1996) 108 (1): 120–125. The Pennsylvanian Fire Clay tonstein
of the Appalachian basin—Its distribution, biostratigraphy, and mineralogy:
Discussion and reply | GSA Bulletin | GeoScienceWorld
Distribution
of rare earth elements in eastern Kentucky coals: Indicators of multiple modes
of enrichment? James C. Hower, Cortland F. Eble, Shifeng Dai, and Harvey E.
Belkin. International Journal of Coal
Geology. Volumes 160–161, 15 April 2016, Pages 73-81. Distribution of rare earth elements
in eastern Kentucky coals: Indicators of multiple modes of enrichment? -
ScienceDirect
Rare
Earth and Critical Element Chemistry of the Volcanic Ash-fall Parting in the
Fire Clay Coal, Eastern Kentucky, USA. Jingjing Liu, Shifeng Dai, Debora Berti,
Cortland F. Eble, Mengjun Dong, Yan Gao & James C. Hower. Clays and Clay
Minerals. Volume 71, pages 309–339, (2023). Rare Earth and Critical Element
Chemistry of the Volcanic Ash-fall Parting in the Fire Clay Coal, Eastern
Kentucky, USA | Clays and Clay Minerals (springer.com)
An
Appalachian isochron: A kaolinized Carboniferous air-fall volcanic-ash deposit
(tonstein). P.C. Lyons. Geological Society of America Bulletin. Volume 104, Issue
11. 1992. An Appalachian isochron: A kaolinized
Carboniferous air-fall volcanic-ash deposit (tonstein) (usgs.gov)
Lanthanide,
yttrium, and zirconium anomalies in the Fire Clay coal bed, Eastern Kentucky. James
C Hower, Leslie Ruppert, and Cortland F. Eble. International Journal of Coal
Geology 39(s 1–3):141–153. 1999. (PDF) Lanthanide, yttrium, and zirconium
anomalies in the Fire Clay coal bed, Eastern Kentucky (researchgate.net)
Altered
volcanic ashes in coal and coal-bearing sequences: A review of their nature and
significance. Shifeng Dai, Colin R. Ward, Ian T. Graham, David French, James C.
Hower, Lei Zhao, and Xibo Wang. Earth-Science Reviews. Volume 175, December
2017, Pages 44-74. Altered volcanic ashes in coal and
coal-bearing sequences: A review of their nature and significance -
ScienceDirect
The
University of Kentucky Conducts Pilot-Scale Testing for REE Extraction and
Recovery in NETL-Supported Initiative. DOE-NETL. February 16, 2021. The University of Kentucky Conducts Pilot-Scale Testing for
REE Extraction and Recovery in NETL-Supported Initiative | netl.doe.gov
Rare
earth elements (REEs) recovery from coal waste of the Western Kentucky No. 13
and Fire Clay Seams. Part I: Mineralogical characterization using SEM-EDS and
TEM-EDS. Bin Ji, Qi Li, and Wencai Zhang. Fuel. Volume 307. January 1, 2022.
Rare earth elements (REEs) recovery
from coal waste of the Western Kentucky No. 13 and Fire Clay Seams. Part I:
Mineralogical characterization using SEM-EDS and TEM-EDS - ScienceDirect
Rare
earth elements (REEs) recovery from coal waste of the Western Kentucky No. 13
and Fire Clay seams. Part II: Re-investigation on the effect of calcination. Bin
Ji, Qi Li, Honghu Tang, and Wencai Zhang. Fuel. Volume 315, May, 1 2022. Rare earth elements (REEs) recovery
from coal waste of the Western Kentucky No. 13 and Fire Clay seams. Part II:
Re-investigation on the effect of calcination - ScienceDirect
Operation
and Process Control Development for a Pilot-Scale Leaching and Solvent
Extraction Circuit Recovering Rare Earth Elements From Coal-Based Sources.
Douglas Kweku Addo. Masters
Thesis. Mining Engineering. University of Kentucky. 2019. OPERATION AND PROCESS CONTROL
DEVELOPMENT FOR A PILOT-SCALE LEACHING AND SOLVENT EXTRACTION CIRCUIT
RECOVERING RARE EARTH ELEMENTS FROM COAL-BASED SOURCES (uky.edu)
American
Resources introduces new subsidiary American Rare Earth to extract metals in
Kentucky. Proactive Investors. October 7, 2020. American Resources introduces new
subsidiary American Rare Earth to extract metals in Kentucky
(proactiveinvestors.com)
Four
takeaways from Southwest Virginia’s critical mineral investigation. Charlie
Paullin. Virginia Mercury. August 8,
2023. Four takeaways from Southwest
Virginia's critical mineral investigation - Virginia Mercury
National
company acquires exclusive rights to Purdue rare-earth element innovations,
critical for clean energy technologies. Purdue University News. February 2,
2021. National company acquires exclusive
rights to Purdue rare-earth element innovations, critical for clean energy
technologies - Purdue University News
Energy-Related
Rare Earth Element Sources. Allan Kolker, Liliana Lefticariu, & Steven T.
Anderson. Chapter Abstract in Rare Earth Metals and Minerals Industries. Springer.
December 29, 2023. Energy-Related Rare Earth Element
Sources | SpringerLink
Salt-loving
bacterium can be genetically engineered to purify rare-earth metals. Keumars
Afifi-Sabet. Live Science. January 10, 2024. Salt-loving bacterium can be
genetically engineered to purify rare-earth metals (msn.com)
Mineralogy
of a rare earth element-rich Manchester coal lithotype, Clay County, Kentucky. James
C. Hower, Dali Qian, Nicolas J. Briot, Madison M. Hood, and Cortland F. Eble.
International Journal of Coal Geology. Volume 220, 1 March 2020, 103413. Mineralogy
of a rare earth element-rich Manchester coal lithotype, Clay County, Kentucky -
ScienceDirect
Rare
earth minerals in a “no tonstein” section of the Dean (Fire Clay) coal, Knox
County, Kentucky. James C. Hower, Debora Berti, Michael F. Hochella, and Sarah
M. Mardon. International Journal of Coal Geology 193 DOI:10.1016/j.coal.2018.05.001.
Rare
earth minerals in a “no tonstein” section of the Dean (Fire Clay) coal, Knox
County, Kentucky | Request PDF (researchgate.net)
Critical
Minerals Problems Need a Critical Minerals Solution: The Case for a Separate
Regulatory Classification. Peter Cook and Seaver Wang. The Breakthrough
Institute. January 26, 2024. Critical
Minerals Problems Need a… | The Breakthrough Institute
H.R.2849
- Rare Earth Magnet Manufacturing Production Tax Credit Act of 2023. 118th
Congress (2023-2024) | H.R.2849 -
118th Congress (2023-2024): Rare Earth Magnet Manufacturing Production Tax
Credit Act of 2023 | Congress.gov | Library of Congress
Green
Approach for Rare Earth Element (REE) Recovery from Coal Fly Ash. Pan Liu,
Simin Zhao, Nan Xie, Lufeng Yang, Qian Wang, Yinghao Wen, Hailong Chen, and
Yuanzhi Tang. Environ. Sci. Technol. 2023, 57, 13, 5414–5423. March 21, 2023. Green Approach for Rare
Earth Element (REE) Recovery from Coal Fly Ash | Environmental Science &
Technology (acs.org)
Environmental
impacts of rare earth production. Petra Zapp, Andrea Schreiber, Josefne Marx,
and Wilhelm Kuckshinrichs. MRS Bulletin. Volume 47, pages 267–275, (2022). March
2022. s43577-022-00286-6.pdf
No comments:
Post a Comment