Oregon State chemists patent water-based method to separate zirconium and hafnium

Separating zirconium from hafnium may be one of the least glamorous problems in chemistry, but it sits underneath two industries that matter enormously: nuclear power and semiconductor manufacturing. The two metals sit next to each other on the periodic table and behave so similarly that researchers at Oregon State University describe the task as one of the most difficult separations known. Zircon, the mineral ZrSiO4, almost always contains trace hafnium, and zircon mining is the principal economic source of both elements.

In their pure forms the two metals do very different jobs. Zirconium is vital in nuclear power generation because it resists corrosion and absorbs very few neutrons, which makes it a favored material for fuel rod cladding. Hafnium is crucial for nuclear energy in the opposite way, since it absorbs neutrons well and goes into control rods. It is equally crucial for semiconductor manufacturing, where its oxide serves as a high-permittivity gate insulator in advanced chips. Both industries need the metals separated at high purity, and neither can work with a mixture.

Getting either metal to that purity requires a separation that has historically been solved with organic chemistry. Only two facilities in the United States perform it at industrial scale: ATI Specialty Alloys & Components in Albany, Oregon, and Westinghouse Electric in Ogden, Utah. Each uses millions of pounds of flammable organic solvent every year. Their liquid-liquid extraction process is energy intensive, and roughly 4% of the solvent is lost to the air as noxious pollution.

On September 22, 2026, Oregon State University announced that chemists in its College of Science have patented a water-based alternative to that solvent-heavy approach, and that in laboratory tests the new chemistry outperformed the industry benchmark by roughly five times.

Key Facts

Phys.org reported on September 22 that Oregon State University scientists have patented a water-based, solvent-free process that separates zirconium from hafnium with a separation factor of 33, far above the industry standard of six to seven. A separation factor describes how strongly a method prefers one element over the other, so a score of 33 against a benchmark of roughly 6.5 amounts to about a fivefold gain in selectivity.

EurekAlert, carrying the Oregon State University press release, reported on September 22 that the study was published in the Journal of the American Chemical Society on September 7, 2026, under DOI 10.1021/jacs.6c10597. The paper carries the title Emergent Hf-Selective Precipitation of Aqueous (Zr,Hf) Thiocyanate Molecules through Nuclearity Control.

The research was led by graduate research assistant Alex Roseborough and May Nyman, a professor of chemistry at Oregon State. Co-authors include Doctor Stephen, Jack McLaughlin, Lev Zakharov, George Donkor-Gyami and Pere Miro. The U.S. Department of Energy and the Murdock Charitable Trust supported the work, and Roseborough is now a metallurgist with the department's National Energy Technology Laboratory.

The OSU method abandons solvent extraction in favor of precipitation. It combines natural zirconium carrying a few percentage points of hafnium impurity with thiocyanate ligands that bind the metal ions, plus choline, an inexpensive and nontoxic chemical used as a food additive. Hafnium-rich species then precipitate out of the aqueous solution. The route is low in energy, free of organic solvent, and produced the top separation factor of 33.

Nyman said the findings are impactful especially as society must move toward more carbon-free and high-density electricity generation, including nuclear energy. Phys.org reported on September 22 that she described the paper as an atomic-level account of how the separation works and of how precipitation-based separations can compete with solvent extraction.

Analysis

What this really means is that one of the hardest separations on the periodic table may not require the solvent chemistry the industry has relied on for decades. Zirconium and hafnium are chemical near-twins, which is exactly why the standard industrial answer has been liquid-liquid extraction with large volumes of organic solvent. A separation factor of 33 achieved in water, with a food additive as a key ingredient, changes the terms of that trade. It also reframes what counts as a practical separation in the first place.

The economics follow the chemistry. ATI and Westinghouse each handle millions of pounds of flammable solvent every year, and roughly 4% of it escapes to the air as noxious pollution. BrightSurf reported on September 22 that the OSU precipitation-based process combines zirconium containing a few percentage points of hafnium impurity, thiocyanate ligands and choline, precipitating hafnium-rich species with a separation factor much higher than the current standard. Fewer inputs, lower energy demand and no solvent emissions all point the same direction on cost.

It is worth being precise about what the number 33 does and does not prove. It is a laboratory result in a peer-reviewed journal, not a demonstrated industrial process. Moving precipitation from a benchtop experiment to a plant that feeds semiconductor and nuclear supply chains is a separate engineering problem, and the two existing facilities have decades of operational experience behind them that no single paper can erase.

The bigger picture here is strategic as much as it is environmental. Only two US facilities perform this separation at industrial scale, which makes the supply chain for reactor-grade zirconium and semiconductor-grade hafnium narrow. A water-based route that cuts solvent use, energy demand and airborne emissions would give that chain a second option without asking either industry to accept lower purity. That combination of greener chemistry and equal or better performance is what makes the patent worth watching.

Why It Matters

Nuclear power and microelectronics are the two demand centers the researchers name, and both are under pressure to grow. Zirconium cladding and hafnium control rods sit at the center of reactor design, while hafnium oxide is a workhorse material in advanced semiconductor manufacturing. Any change in how the two elements are purified therefore reaches two sectors at once, and it reaches them at a moment when both are being asked to expand.

The environmental case is concrete. Replacing millions of pounds of flammable organic solvent with water and choline removes a fire hazard and a pollution stream at the same time. The roughly 4% solvent loss that currently reaches the air would not exist in a process built around precipitation from an aqueous solution, and the energy savings follow from dropping an energy-intensive extraction step.

The patent matters too. Oregon State University has secured intellectual property on the method, which positions it to license the chemistry rather than release it into the public domain. That is usually how a laboratory result becomes an industrial option, and it explains why a university chemistry department is announcing a process rather than only a paper.

Next Up

The authors framed the result as a demonstration that precipitation-based separations can compete with solvent extraction, and the natural next step is testing that claim outside the laboratory. Scaling the process, verifying purity at the levels semiconductor and nuclear customers require, and comparing full lifecycle costs against the two existing plants are the obvious items on the agenda.

Funding from the U.S. Department of Energy and the Murdock Charitable Trust supported the discovery. Phys.org reported on September 22 that the work appears in the Journal of the American Chemical Society, giving the team a peer-reviewed foundation to build on as it looks for partners willing to move the chemistry from glassware to production.