Rare-Earth Solvent Extraction Patents: Who Leads, Trends 2026
Filing growth compares 2021 (86 records) with 2024 (48) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 1,037 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This landscape tracks 1,037 patent families filed between 2015 and mid-2026 that describe rare-earth solvent extraction, lanthanide separation and related extractant chemistry. The scope spans process patents for splitting rare-earth mixtures with organic extractants, ionic-liquid and split-anion extraction routes, and downstream recovery from ores, red mud and secondary feedstocks such as e-waste and magnets. C22B, the metal extraction and refining subclass, anchors the field at 76.0% of records, with separation-process, rare-earth compound and wastewater-treatment classes forming the technical periphery.
The filing curve peaked in 2020 and has since eased, though the most recent years are understated because publication typically lags filing by roughly 18 months. Assignee activity is led by a mix of Chinese state-linked rare-earth producers, Japanese chemical majors and a long tail of universities and single-filing entrants, with the receiving-office mix showing China as the primary filing venue by a wide margin.
Filing trends and technology composition
The figures below are drawn directly from the 1,037 records in scope, covering filing volume by year, receiving-office distribution and IPC subclass composition.
Filing trend: a 2020 peak, then a cooling
Filings rose from 43 in 2017 to a peak of 97 in 2020, then eased to 48 by 2024 — a -44% move from the 86 filed in 2021. Counts for 2025 and 2026 are still incomplete because publication lags filing by roughly 18 months, so the recent-year decline should not be read as the technology losing momentum.
IPC composition: refining dominates, separation and compounds trail
C22B (metal extraction and refining) covers 76.0% of the 1,037 records, far ahead of B01D separation processes at 11.2% and C01F rare-earth compounds at 10.4%. Because records can carry multiple IPC classes, these shares sum to more than 100% and should be read against the full record total, not against each other.
Shares are the percentage of the 1,037 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Critical-Mineral Refining & Separation: Rare-Earth Solvent Extraction Patent Landscape with Eureka
This page is one run against one query. Ask Eureka your own question about critical-mineral refining & separation: rare-earth solvent extraction patent landscape and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records and a representative filing
US20200239982A1 — Prediction Control Method And System For Component Contents In Rare Earth Extraction Process
Filed by East China Jiaotong University, this record discloses an Elman neural-network model that predicts component contents in a rare-earth extraction process, calculates an optimal steady-state set value, and dynamically adjusts extractant and detergent flow increments to control output composition.Process-control patent rather than a new extractant chemistry — it claims the control loop, not the separation reagent itself.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5030424A | Recovery of rare earth elements from Bayer process red mud | 92 |
| 2 | WO2015106324A1 | Process for extraction and separation of rare earths by split-anion extraction with ionic liquids | 51 |
| 3 | CN102382982A | 一种液-液-液三相体系萃取分离稀土离子的方法 | 50 |
| 4 | CN101363079A | 一种富铁独居石稀土矿的冶炼方法 | 50 |
| 5 | US5015447A | Recovery of rare earth elements from sulphurous acid solution by solvent extraction | 48 |
| 6 | CN101824536A | 一种从硫酸处理磷矿过程中提取稀土的工艺 | 45 |
| 7 | US5011665A | Nonpolluting recovery of rare earth values from rare earth minerals/ores | 44 |
| 8 | US20150104361A1 | Processes for recovering rare earth elements and rare metals | 43 |
| 9 | US5708958A | Method of separating trivalent actinides and rare earth elements | 40 |
| 10 | CN102766766A | 一种无皂化稀土萃取分离工艺 | 37 |
Citation counts favour older filings within the searched corpus and should be read as a signal of influence, not of current commercial importance.
Patent titles are shown in the language they were filed in, not translated, so that each record stays verifiable against the original filing — a translated title will not match in Eureka or in any national register. Each row carries its publication number; clicking a row searches Eureka by that number.
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Three patterns stand out once volume, geography and citation data are read together.
A visible leader, not a lockout
The leading assignee holds 35 records against a fifth-place count of 23, and the top five combined reach 150 of the 1,037 records in scope. That leaves the large majority of filings spread across a long tail, so the field is led rather than gated by a single dominant holder.
China is the primary filing venue by a wide margin
China's receiving office accounts for 653 of the tracked records, more than five times the 129 filed in the United States and well ahead of the 43 filed via the WIPO PCT route. Filing strategy in this field has to account for the density of prior art already on file in China.
Volume eased after the 2020 peak
Filings fell from 86 in 2021 to 48 in 2024, a -44% move, after peaking at 97 in 2020. Because publication lags filing by roughly 18 months, the 2025-26 figures are still incomplete and should not be read as a further slowdown.
Older red-mud and sulphurous-acid recovery patents anchor the citation graph
The most-cited record in scope addresses recovery of rare earths from Bayer-process red mud, cited 92 times, with a second cluster of older recovery patents also drawing heavy citation. This reflects the age of the corpus as much as ongoing relevance — newer ionic-liquid and split-anion extraction routes have not yet had time to accumulate comparable citation counts.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to critical-mineral refining & separation: rare-earth solvent extraction patent landscape, with the prior art for and against each one.
Where to take this analysis
The figures above frame the field; the next steps depend on whether the goal is freedom-to-operate, portfolio benchmarking or identifying a filing gap.
Map claims against your own process route
Cross-check the specific extractant chemistry, feedstock and separation step you use against the most-cited and most-recent records in C22B and B01D to see where claim language actually overlaps your process.
Explore claim charts in EurekaWatch the assignees still filing after the 2020 peak
Momentum has cooled broadly, but the assignees still active past 2021 indicate where competitive filing pressure is concentrated now rather than five years ago.
Track assignee activity in EurekaTest white-space claims before committing R&D
The under-claimed branches identified here are starting points, not guarantees of freedom to operate — a targeted novelty search against the full 1,037-record set will confirm whether a first claim actually holds.
Run a novelty search in EurekaFrequently asked questions
The dataset's ranked leader holds 35 of the 1,037 records in scope, with the fifth-place assignee at 23 and the tenth at 18. The top five combined account for 150 records, or 14.5% of all records in scope, so no single company controls the field outright. The remainder is spread across a long tail of Chinese rare-earth producers, universities and single-filing entrants, which matters for freedom-to-operate work because the risk is distributed rather than concentrated in one blocking portfolio.
Filing volume rose steadily to a peak of 97 in 2020, then eased to 48 by 2024, a -44% change from the 86 filed in 2021. That looks like a slowdown, but publication typically lags filing by around 18 months, so the 2025 and 2026 counts in this dataset are still incomplete and understate real filing activity. Treat the post-2020 numbers as a cooling from an unusually active peak rather than a definitive downward trend.
China's receiving office accounts for 653 of the tracked records, far ahead of the United States at 129, the WIPO PCT route at 43, Australia at 40, Europe at 32 and Canada at 28. This concentration reflects both the location of rare-earth processing capacity and the density of domestic Chinese filers such as regional rare-earth material producers. Anyone assessing freedom to operate in this space needs to weight prior-art searching toward Chinese-language filings accordingly.
C22B, the metal extraction and refining subclass, appears in 76.0% of the 1,037 records in scope, making it by far the dominant classification. Separation processes (B01D, 11.2%) and rare-earth compound chemistry (C01F, 10.4%) form a secondary tier, with water treatment, acyclic compounds, mixing equipment and catalysis classes trailing further behind. Because a single record can carry several IPC codes, these shares add up to more than 100% and should each be read against the full 1,037-record total rather than against one another.
Reading the IPC composition alongside citation patterns, ionic-liquid and split-anion extraction chemistries, process-control modelling for extraction circuits, and secondary-feedstock recovery from magnet scrap all sit inside well-populated parent classes but show comparatively thin direct claim coverage in this dataset. That does not guarantee freedom to operate, but it flags where a well-drafted first claim is more likely to clear existing art. A targeted search against the full record set is still needed before committing R&D spend to any one branch.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.