Tag: REEs

Recovering in-demand metals for new electronics

Recovering in-demand metals for new electronics

Nearly all technology today—from cellphones to computers to MRI scanners—contains rare earth elements (REEs). The global market for REEs is predicted to reach $6.2 billion (USD) this year and $16.1 billion (USD) by 2034.

High concentrations of one particular REE — lanthanum — are often in find in mine tailings. Runoff from this waste can make its way into nearby bodies of water where it poses a risk to human health and the environment. As a result, researchers are on the hunt for ways to recover the material.

Michael Chan, working under the supervision of Dr. Huu Doan in the Department of Chemical Engineering at Toronto Metropolitan University (TMU), recently discovered that industrial-strength chemical adsorbents can be used to “soak up” lanthanum from that mine waste.

“These ‘fancy sponges’ are about the size of a grain of salt,” says Chan, who is completing his Masters degree at TMU. Working in a lab, Chan and his colleagues found that the metal ions present in a sample of contaminated water trade places with the hydrogen ions present on the surface of adsorbent.

When they filtered the adsorbent out of the water, they were left with cleaner water and recovered lanthanum that could be reformed and reused in new electronics.

The team used a scanning electron microscope at TMU to better understand the ion exchange process, then used the Canadian Light Source at the University of Saskatchewan to get even more detailed images and to confirm their findings.

Read more on CLS website

A greener possibility using lanthanide separation in two dimensions

A greener possibility using lanthanide separation in two dimensions

The lanthanides and other rare earth elements (REEs) aren’t really “rare” in the strict sense, but they are quite difficult to separate and purify from the other materials with which they’re usually found. Because of the great value and utility of these metals for many purposes, including electronics, computing, and various industrial processes that rely on their unique electronic and chemical properties, that difficulty is a major problem. 

Most current processes for REE separation and purification involve organic and acidic materials, making them both energy-intensive and environmentally unfriendly. Finding better separation techniques is therefore a pressing challenge. Researchers from the University of Chicago, Northwestern University, and Argonne National Laboratory took inspiration from nature to examine a new possibility for lanthanide separation. Their work was published in Science Advances. 

Noting that ion channels in cell membranes are capable of separating ions across cell membranes with great efficiency, speed and selectivity, the investigators chose to model this process with chemically functionalized inorganic membranes to see if REE purification could be accomplished in a similar way.  They constructed two-dimensional angstrom-scale artificial ion channels using MoS2 nanosheets that were covalently functionalized with acetic acid to generate MoS2-COOH membranes for lanthanide ion separation. 

The ion transport process was studied using a variety of tools, including electron microscopy, infrared spectroscopy, molecular dynamics simulations and X-ray absorption spectroscopy and X-ray diffraction studies. Data were collected at the DuPont-Northwestern-Dow Collaborative Access Team 5-BM-D beamline at the Advanced Photon Source, a U.S. Department of Energy (DOE) user facility at DOE’s Argonne National Laboratory.

Read more on Argonne website

Recovering rare earth elements from coal ash for clean energy technologies

Recovering rare earth elements from coal ash for clean energy technologies

As the world transitions away from fossil fuels, the demand for rare earth elements (REEs) is only going to increase. These elements are vital to the production of technologies that will make the transition to green energy possible. While REEs are not technically rare, large deposits are found in only a few locations around the world – mostly in China – and they are difficult to extract.

“If we want to switch to electric vehicles by 2035 and be net-zero by 2050 we’re going to need new sources of these metals,” says Brendan Bishop, a PhD candidate studying REEs at the University of Regina.

Bishop and his colleagues have been studying one potential new source of these valuable elements: the ash that is produced as waste from coal-fired power plants. Researchers have looked into REEs in coal waste in the United States and China, but there has been little work done on ash from Canadian coal.

The team analyzed samples of ash from coal plants in Alberta and Saskatchewan to determine how much REEs the ashes contained, and how they could be extracted. While the concentration of REEs in Canadian coal ash is on par with that found in ash from other parts of the world, questions remained about whether the REEs are dispersed evenly throughout the ash particles or concentrated in certain minerals found within the ashes.

Using the powerful X-ray beamlines at the Canadian Light Source (CLS) at the University of Saskatchewan (USask), Bishop probed the ash, in search of a rare earth element called yttrium. They found it was distributed in specific mineral phases within the ash particles, most often in the form of silicates or phosphates such as xenotime which remain unchanged when the coal is burned.  The work was published in Environmental Science and Technology.

Read more on CLS website