As global demand for high-tech and sustainable energy technologies intensifies, so does the need for a reliable supply of rare earth elements (REEs). These critical materials power everything from electric vehicles to wind turbines, but their supply chain remains precarious. In this month’s Video in the Spotlight, Dr. Yuanzhi Tang from Georgia Tech’s School of Earth and Atmospheric Sciences offered a compelling multiscale scientific roadmap for reclaiming REEs from an unconventional and abundantly available source: coal fly ash.
Fly ash, a waste byproduct of coal combustion, represents a dual opportunity. On one hand, it is a widely distributed environmental liability; on the other, it harbors REE concentrations that rival or exceed those found in mineable ores. Dr. Tang’s team employs a multiscale approach that begins at the molecular level—probing the chemical speciation and physical distribution of REEs—and scales up to the design of extraction and stabilization techniques. This includes using synchrotron X-ray spectroscopy, scanning electron microscopy, and thermodynamic modeling to track REE transformations through high-temperature processes and correlate them with extractability in acidic and ligand-assisted conditions.
What emerges is a sustainable, closed-loop system: REEs are selectively leached from fly ash using biodegradable organic acids like citrate, recovered through oxalate precipitation, and residual waste is converted into zeolites for heavy metal immobilization. This not only recovers valuable materials but also dramatically reduces the volume and toxicity of industrial waste. Dr. Tang’s work exemplifies how fundamental geochemistry and advanced materials characterization can unlock new pathways for both resource recovery and environmental stewardship.
Here's a quiz based on the webinar. Check back next month or in The Bridge Digest for the answers!
1. What makes rare earth elements (REEs) difficult to mine from conventional sources? A) They are typically dispersed and not concentrated in mineable ores B) They are only found on the moon C) They are usually radioactive D) They are soluble in water
2. What role does citrate play in the REE extraction process? A) Acts as a reducing agent for iron B) Precipitates REEs directly C) Stabilizes toxic waste D) Acts as a biodegradable ligand to enhance REE solubility
3. What physical feature of Class F fly ash makes REE extraction more difficult compared to Class C? A) Higher iron content B) Presence of magnetic minerals C) Greater glass-phase encapsulation of REEs D) Higher moisture content
4. Which REE mineral types were found to be stable through coal combustion? A) REE carbonates B) REE oxides C) REE phosphates and silicates D) REE organic complexes
5. What is one of the environmental advantages of Dr. Tang’s closed-loop treatment system? A) It uses only water and air as reagents
B) It minimizes secondary waste production and stabilizes residues as zeolites C) It completely neutralizes all heavy metals D) It eliminates the need for thermal processing
Upcoming Events
Protein Society Meeting | San Francisco, CA | Jun 26 - 29, 2025 | Website
Analysis of Alternative Fuels Using XRF | Webinar| Jun 26, 2025 |Website
Texas School District Police Chiefs Association Conference | Galveston, TX | Jun 29 - Jul 13, 2025 | Website
Solving Pharma’s Toughest Solid Form Challenges with Electron Diffraction | Webinar | Jun 4, 2025 |Website
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2025 European School on Magnetism | Cambridge, UK | Jun 30 - Jul 11, 2025 | Website
The Advanced Materials Show and The Advanced Ceramics Show 2025 | Birmingham, UK | Jul 9 - 10, 2025 |Website
Revealing Atomic-Level Battery Material Structures with Electron Diffraction | Webinar | Jul 9, 2025 |Website
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Stop by the Rigaku booth #21 to see a mockup of our new microfocus sealed-tube source, the PhotonJetMAX-S. We will also be celebrating the 10-year anniversary of the merger between Rigaku and Oxford Diffraction with a special T-shirt giveaway and two fun contests.
Wear your free T-shirt around the conference or the city and share your photos online to compete for a chance to win a $150, $100, or $50 gift card. Winners will be chosen based on the number of likes their photo receives by July 28 at 10:00 AM Central Time.
Or join us at the booth on July 20 at 6:30 PM during the poster session for a prize draw. Two attendees will be awarded $100 each, but you must be present and wearing the T-shirt to claim your prize.
Throughout the three-day exhibit, Rigaku team members will also be offering guidance for solving challenging datasets, navigating publication, or exploring careers at vendor companies. Just stop by booth #21 and ask.
In high-stakes environments where every second matters, having the right intelligence can mean the difference between safety and disaster. While Icon-X is Rigaku's fourth generation in its line of 1064 nm Raman analyzers, it is the first to provide standoff chemical analysis in order to scan potentially dangerous substances from a safe distance. This is critical for military, first responders, EOD, and border protection teams who could potentially be exposed to explosive threats, such as improvised explosive devices (IEDs), homemade explosives (HMEs), and chemical threats. This new feature also reduces the need for time-consuming sample collection, while allowing responders to assess hazards without disrupting the scene.
Users now have the unique ability to scan samples from a distance or scan with contact - providing more versatility in stressful environments.
Join us for the next MiniFlex Office Hour on July 15, 2025, at 10:30 AM CDT, a LinkedIn Live session where we’ll answer your real-time questions about the MiniFlex X-ray diffractometer. Hosted by Akhilesh Tripathi, X-ray Diffraction Application Manager, and Aya Takase, Head of Global Marketing Communications at Rigaku, this interactive session is your chance to connect, ask questions, and explore all things MiniFlex. Whether you're new to XRD or a longtime user, we welcome your insights.
This is just the beginning of a recurring series, so stay tuned for more opportunities to join the conversation. You can alsobrowse all previous episode recaps here. Drop your questions in the chat, and let’s talk XRD!
Rare earth elements (REEs) are critical for sustainable technologies but face challenges in supply chain security and environmentally intensive extraction methods. Coal fly ash (CFA), a byproduct of coal combustion, has emerged as a promising alternative REE source due to its high annual production, fine particle size, and significant REE content. This talk presents a multiscale geochemical investigation of REE speciation, distribution, and extractability in CFA. Using synchrotron-based X-ray absorption spectroscopy and microscopy, combined with thermodynamic modeling and selective leaching experiments, we reveal how REE-bearing phases—particularly oxides, phosphates, and encapsulated species within glass matrices—govern recovery potential.
Distinct behaviors between Class C and Class F CFA are linked to mineralogical differences, informing optimized extraction strategies. A green, closed-loop recovery method using biodegradable ligands (citrate) and selective precipitation (oxalate) was developed, yielding enriched REE oxalate solids while minimizing secondary waste. Residuals were further converted into zeolite materials for heavy metal immobilization. This approach demonstrates the importance of molecular-scale understanding in designing sustainable resource recovery pathways from complex industrial waste.
May 28, 2025: Since graphene’s discovery two decades ago, the iconic 1-atom-thick sheet of carbon has inspired researchers to create a growing family of other 2D materials. Most are compounds, but almost 20 are composed of a single element—including silicon, boron and gold—and are collectively known as Xenes. Researchers in China have nowisolated and studied the first halogen Xene: iodinene.
June 2, 2025: Despite advances in machine vision, processing visual data requires substantial computing resources and energy, limiting deployment in edge devices. Now, researchers from Japan have developeda self-powered artificial synapse that distinguishes colors with high resolution across the visible spectrum, approaching human eye capabilities. The device, which integrates dye-sensitized solar cells, generates its electricity and can perform complex logic operations without additional circuitry, paving the way for capable computer vision systems integrated in everyday devices.
June 5, 2025: For decades, scientists have struggled to understand what, exactly, is happening inside a solid-state battery in real time, which has made extending its life difficult. Now, researchers have worked around that problem usingoperando scanning electron microscopy, a powerful high-resolution imaging technique. The technique helped them understand why solid-state batteries break down and what could be done to slow the process.
June 18, 2025: The cement industry produces around eight percent of global CO₂ emissions – more than the entire aviation sector worldwide. Researchers at the Paul Scherrer Institute have developed an AI-based model that helps to accelerate the discovery of new cement formulations that could yield the same material quality with a better carbon footprint.
Featured Application Notes
Standardless FP Analysis of Lithium-ion Battery Cathode Material LiFePO₄ by ZSX Primus IV
In recent years, the demand for lithium-ion batteries (LIBs) has increased significantly with the widespread adoption of battery electric vehicles (BEVs) and energy storage systems (ESSs) aiming for carbon neutrality. Lithium iron phosphate (LiFePO₄), which is used as a low-cost and safe cathode material in LIBs, contains Fe as a major component. Because the composition of the electrode active material and trace impurities affect battery performance, the concentration of main components Li, Fe, P and trace impurities such as Cu, Na, Ca and Zn should be controlled. As a non-destructive elemental quantification method, X-ray fluorescence allows sample analysis for powders and electrode plates without complicated sample preparation such as acid digestion.
In standardless FP analysis (SQX analysis), qualitative scan analysis is run at first and then composition is calculated by the fundamental parameter (FP) method using X-ray intensities of detected elements and FP sensitivity libraries. Compositional calculation can be performed without preparing any standard samples and calibration curves. In this application note, SQX analysis was performed for cathode material LiFePO₄ to determine the concentration of Fe, P and trace components using the wavelength dispersive X-ray fluorescence spectrometer ZSX Primus IV. In addition, applicability of the ZSX Primus IV was evaluated with reference to the Nonferrous Metals Industry Standard of the People’s Republic of China, YS/T 1028.5-2015, a standard for the chemical analysis of trace components in LiFePO₄ by using ICP atomic emission spectrometry (ICP-AES).
Petroleum-based petrochemical polymers such as polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET, PETE), and polyvinyl chloride (PVC) often contain compound additives that help achieve specific properties desired in the polymer. These additives include lubricants, plasticizers, stabilizers, anti-block, impact modifiers, and flame retardants and typically include elements such as Mg, Al, Si, P, Cl, Ca, Ti, Zn, Br, and Sb. During the production process, the elemental composition must be measured to ensure that the polymer formulations meet targeted specifications. To maintain proper quality control during production, test samples are made, and the trace elements are measured.
Energy dispersive X-ray fluorescence (EDXRF) offers a fast, non-destructive method for performing elemental analysis in various sample forms. Applied Rigaku Technologies provides a full line of benchtop EDXRF analyzers, such as the NEX QC+ QuantEZ. They are well-suited for quality control applications throughout the polymer manufacturing process due to their intuitive software interface, innovative design, and powerful analytical performance. Rigaku EDXRF systems make an excellent tool for quality control checks at several places along the polymer production process.
Identification of hazardous compounds and illicit drugs with handheld Raman spectrometers
By Taro Nogami
Raman spectrometry is becoming a common method for identification of hazardous compounds and illicit drugs. Historically, infrared absorption spectroscopy was the common method, but the mainstream has gradually shifted to Raman spectroscopy. Raman spectrometry has a couple of advantages over infrared spectrometry for onsite rapid analysis. First, handheld Raman spectrometers can analyze contents through transparent or translucent containers, which infrared absorption spectrometers cannot. Second, Raman spectrometer can analyze wet samples, but infrared absorption spectrometer cannot.
The novel handheld Raman spectrometers for hazardous materials and drugs with 1064 nm excitation laser described in this article can drastically reduce the overlap of fluorescence seen with previous spectrometers that used 785 nm lasers.
Small Crystals, Big Insights: How Electron Diffraction is Transforming Materials, Life Science, and Chemistry Research
Revealing Atomic-Level Battery Material Structures with Electron Diffraction
Wednesday, July 9, 2025 9:00 AM CDT
Do you work with tiny, impure samples in drug development where you still need structural insights like connectivity or polymorphism?
In this session, we will explore how Micro Electron Diffraction (MicroED) can address some of the toughest solid form challenges in pharmaceutical development, particularly when working with sub-milligram samples that are impure, highly disordered, or nanocrystalline. You will learn how MicroED supports structural characterization during early discovery and development, including determining connectivity and polymorphism in imperfect crystals and evaluating disorder caused by processing. The session will also include real-world examples, such as polymorph screening and analysis of nanoparticle delivery systems, showing how MicroED helps guide better decisions throughout the drug development process. Join us to learn more.
Do you mostly rely on chemical analysis to evaluate your products? What if you could verify pharmaceutical materials instantly, with no delays or lab wait times?
In this session, we delve into how X-ray computed tomography (CT) and handheld Raman spectroscopy are transforming pharmaceutical manufacturing and quality control. Our experts, Angela Criswell, PhD, and Suzanne Schreyer, PhD, will discuss how these technologies provide deeper insight into your products and faster answers on the manufacturing floor.
The Opioid Matrix is a podcast for anyone looking for the latest information in the illegal drug supply chain—beginning to end. Each episode will feature a discussion with industry experts about the current opioid crisis, including drug trafficking, drug manufacturing, drug identification, drug addiction, as well as the role of government, law enforcement, new health and social programs, and more.
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