DRI Handling Patents: Top Companies & Filing Trends 2026
- 41.8% of the field sits with the top five assignees out of 596 records in scope, but the tenth-ranked filer holds only 16 — a long tail follows the leaders.
- Filings dropped 66% from 65 in 2021 to 22 in 2024, after peaking at 85 in 2022, following the sharpest documented run-up in HBI reduction and briquetting activity.
- C21B iron production carries 58.4% of records, while coating and surface deposition (C23C) — the class most relevant to passivation chemistry — sits at just 3.4%.
Filing growth compares 2021 (65 records) with 2024 (22) — 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 596 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Direct reduced iron (DRI) and hot briquetted iron (HBI) are reactive intermediates: freshly reduced iron reoxidizes readily on contact with air or moisture, generates fines during handling, and carries bulk-density and packing behaviour that governs everything from briquetting-press design to inert-gas storage and marine transport safety. This landscape tracks patent activity where those handling problems intersect with the core reduction process — passivation chemistry, briquetting equipment, and the storage and transport engineering built around reoxidation risk. It draws on 596 published records filed or published between 2015 and mid-2026.
The scope deliberately sits at the seam between metallurgy and materials handling: it captures reduction and furnace patents only where they touch passivation, briquetting, fines control, bulk density or inert-gas storage, rather than the whole of direct-reduction ironmaking.
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Filing trend and technology composition
Two views of the same 596 records: how filing activity has moved year on year, and which IPC subclasses carry the underlying technical content. Because a single record can carry several IPC classes, the composition shares add up to well over 100%.
A sharp run-up, then a pullback that predates the publication lag
Filings rose from 22 in 2017 to a peak of 85 in 2022, then fell to 22 by 2024 — a 66% drop over that three-year span. Publication typically lags filing by around 18 months, so 2025 and 2026 figures are still filling in and should not yet be read as a continued decline.
Reduction and refining dominate; surface chemistry is thin
C21B (iron production) appears in 58.4% of records and C22B (metal extraction and refining) in 27.3%, confirming that most activity is anchored in the core reduction process rather than downstream handling. H01M (batteries, cells and fuel cells) reaching 18.0% reflects DRI's growing role as a feedstock discussion point in hydrogen-linked energy patents. C23C (coating and surface deposition), the class closest to passivation coatings themselves, sits at only 3.4%.
Shares are the percentage of the 596 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Direct Reduced Iron Handling with Eureka
This page is one run against one query. Ask Eureka your own question about direct reduced iron handling and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited and most recent filings
Induction Heating of DRI (US20240392399A1, ArcelorMittal Texas HBI LLC, filed 2024)
A process for manufacturing hot briquetted iron (HBI) from direct reduced iron (DRI): iron ore is direct-reduced using a reducing gas of natural gas, hydrogen and/or carbon monoxide at elevated temperature, then discharged to a briquetting device. The distinguishing step is reheating the DRI after it leaves the reduction reactor and before briquetting, to bring it to a target briquetting temperature using induction heating.Filed by ArcelorMittal's Texas HBI operation, this sits squarely in the briquetting-temperature-control niche rather than the reduction reaction itself.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5082251A | Plant and process for fluidized bed reduction of ore | 158 |
| 2 | US5730775A | Method for rapid reduction of iron oxide in a rotary hearth furnace | 115 |
| 3 | US5601631A | Process for treating metal oxide fines | 75 |
| 4 | US5192486A | Plant and process for fluidized bed reduction of ore | 74 |
| 5 | US6413295B2 | Iron production method of operation in a rotary hearth furnace and improved furnace apparatus | 73 |
| 6 | US20130081516A1 | Direct Production of Iron Slabs and Nuggets From Ore Without Pelletizing or Briquetting | 70 |
| 7 | US5656044A | Method and apparatus for gasification of organic materials | 68 |
| 8 | US20210028452A1 | Rechargeable battery using iron negative electrode and manganese oxide positive electrode | 64 |
| 9 | US5885521A | Apparatus for rapid reduction of iron oxide in a rotary hearth furnace | 58 |
| 10 | US20060278040A1 | Process for producing reduced matal and agglomerate with carbonaceous material incorporated therein | 57 |
Citation counts favour older filings simply because they have had longer to accumulate citations within this searched corpus — treat them as a signal of influence on the field, not of current technical importance. The fluidized-bed and rotary-hearth reduction patents from the 1990s anchor much of the later citation activity.
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Three readings of the same dataset that matter for a filing or freedom-to-operate decision.
Leadership is concentrated but not locked
The top five assignees combine for 41.8% of all 596 records, and the top ten reach 57.0%. But the drop from the leader (108) to fifth place (23) to tenth (16) is steep — this is a field with one dominant filer and a wide field of moderate-volume challengers, not a duopoly.
Activity has cooled from its 2022 peak
Filings peaked at 85 in 2022 and fell to 22 by 2024, a 66% decline across the three-year span. Recent-year momentum by assignee shows most tracked leaders at zero filings in the latest year, though 2025-2026 counts are still incomplete given typical publication lag.
Passivation chemistry is thinly claimed relative to reduction equipment
C21B and C22B together cover the bulk of filings, but C23C — the class most directly tied to passivation coatings and surface treatments that prevent reoxidation — sits at only 3.4% of the 596 records. That gap is notable given how central reoxidation risk is to the search scope itself.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to direct reduced iron handling, with the prior art for and against each one.
| Assignee | Co-assignee | Shared families |
|---|---|---|
| ILSA Cost SPA | PROLER ENVIRONMENTAL SERVICES INC | 6 |
| Nu Iron Technology LLC | LINDGREN ANDREW L | 3 |
| Nu Iron Technology LLC | LALICH MICHAEL C | 3 |
| Nu Iron Technology LLC | KIESEL RICHARD F | 3 |
| Nu Iron Technology LLC | IWASAKI IWAO | 3 |
| Nu Iron Technology LLC | BLEIFUSS RODNEY L | 3 |
| Nu Iron Technology LLC | BEAUDIN ROBERT C | 3 |
| Midrex Technologies Inc | MEDREX TECH INC | 2 |
Only 10 co-assignee pairs appear in the dataset, and the strongest pairing links an equipment engineering firm with an environmental-services specialist — suggesting most DRI handling IP is developed in-house rather than through joint filing.
Who is filing, and what is left open
The ranked leaders span reduction-process originators, briquetting equipment makers, and newer hydrogen-metallurgy entrants. Momentum has slowed across nearly all of them in the latest tracked year, consistent with the field-wide pullback from its 2022 peak.
One filer sits well ahead of the field
The leading assignee's 108 records outpace fifth place (23) by more than four times, reflecting a long-running program spanning reduction, briquetting and furnace design rather than a single-technology bet.
A mid-tier of equipment and plant suppliers
Below the leader, filers cluster around briquetting press design, rotary hearth and fluidized-bed furnace configurations — the mechanical side of DRI handling rather than the chemistry of passivation.
Hydrogen-linked entrants are filing but pulling back
Newer entrants tied to hydrogen-based reduction routes show filings in the latest tracked year but at reduced volume year-on-year, alongside several established players registering zero filings in that same year.
| Assignee | Recent year | YoY |
|---|---|---|
| Form Energy Inc | 2 | -60% |
| JFE Steel Corporation | 1 | 0% |
| Midrex Technologies Inc | 0 | — |
| Nu Iron Technology LLC | 0 | — |
| ILSA Cost SPA | 0 | — |
| Midrex International BV Zurich Branch | 0 | — |
| GreenIron H2 AB | 0 | — |
| HYBRIT Development AB | 0 | — |
Where to take this analysis
The landscape points to specific questions worth running deeper diligence on before committing a filing strategy.
Map the passivation coating white space in detail
With C23C at just 3.4% of records against a search scope centred on reoxidation risk, a claim-by-claim review of that thin slice could surface genuinely open ground.
Explore in Patsnap EurekaTrack the leader's briquetting-temperature claims
Recent filings like the induction-heating patent suggest the temperature-control step between reduction and briquetting is an active claiming zone worth monitoring for design-around risk.
Run a freedom-to-operate check in Patsnap EurekaCommon questions on DRI handling patents
One assignee leads the field clearly, with 108 records versus 23 for the fifth-ranked filer and 16 for the tenth. The top five assignees combined hold 41.8% of the 596 records in scope, and the top ten hold 57.0%. That said, the ranked list runs to 100 companies, so there is a substantial long tail of moderate and single-filing entrants beyond the leaders — this is a concentrated-at-the-top field, not a two-company market.
Direct reduced iron is highly reactive immediately after reduction and will reoxidize on exposure to air or moisture, which creates fire, heat-buildup and transport-safety risks — this is why passivation, inert-gas storage and bulk-density control all sit inside the same search scope. Despite that centrality, the IPC class most tied to surface coating and passivation chemistry (C23C) appears in only 3.4% of the 596 records, well behind core reduction (C21B, 58.4%) and refining (C22B, 27.3%) classes. That gap suggests coating-specific claim space is less crowded than the reduction and furnace equipment around it.
Filings rose steadily to a peak of 85 in 2022, then fell to 22 by 2024 — a 66% decline over that three-year window, using the most recent year that can be treated as complete. Publication lags filing by roughly 18 months, so the 2025 and 2026 figures in any dataset are still incomplete and should not be read as evidence of a continuing drop. Recent-year momentum by assignee shows most tracked leaders at zero filings in the latest year, which is consistent with either genuine slowdown or simply incomplete recent-year data — the two are hard to separate this close to the cut-off.
The patent, filed by ArcelorMittal's Texas HBI operation, covers a process where DRI is reheated to a target briquetting temperature — specifically via induction heating — after leaving the reduction reactor and before it enters the briquetting press. It does not claim the reduction reaction itself or the briquetting press mechanism; its scope is the intermediate reheating step and the use of induction heating to hit that temperature target. Anyone using a different heating method for that intermediate step, or skipping reheating entirely by managing reactor discharge temperature directly, is working outside this claim's likely scope, though a full claim-chart review is needed before relying on that reading.
The clearest gap by class density is passivation coating chemistry (C23C at 3.4% of 596 records) relative to how central reoxidation risk is to the field's core problem. Inert-gas storage vessel design and fines suppression during transfer also show comparatively thin, equipment-specific filing relative to the volume of activity in core reduction and furnace classes. These are read from filing density, not technical maturity — thin filing density means the claim space is less occupied, not that the underlying engineering problem is unsolved.
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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.