Copper Smelting Patents: Who Leads, Where the Gaps Are 2026
- 85.5% held by five. Of the 83 records in scope, the top five assignees combined account for 71 records — 85.5% of the field — leaving a thin tail below them.
- Filings peaked in 2020, not now. Annual filings hit 15 in 2020 and had fallen to 3 by the 2022 midpoint, a flat-to-declining trend rather than a growing one.
- Claims cluster in one IPC subclass. C22B (metal extraction and refining) covers 84.3% of the 83 records; electrorefining-specific C25C covers only 15.7%, pointing to where claim density thins out.
What this landscape covers
This landscape tracks patent families addressing copper smelting and copper electrorefining, filtered to documents that discuss matte grade, SO2 capture, anode casting, cathode purity or impurity deportment, and classified under metal extraction (C22B), electrolytic metal production (C25C) or metal refining (C22B5). The scope spans 83 published records filed between 2015 and the July 2026 data cut-off.
Publication typically lags filing by around 18 months, so the most recent filing years in this dataset understate actual activity. Even allowing for that lag, the trend line through the 2022 midpoint shows filings well off the 2020 peak, which is a signal about the maturity of the claim space rather than about interest in the underlying metallurgy.
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Filing trend and technology composition
Two views of the same 83-record dataset: filings by year, and the IPC subclasses those filings are classified under. Because a single record can carry several IPC codes, the subclass shares sum to more than 100% of the record total.
Filings by year, 2015–2026
Filings rose to a peak of 15 in 2020, then declined; by the 2022 midpoint the annual count was down to 3, indicating a flat-or-declining trend rather than sustained growth. The 2026 figure is a partial year and should not be read as a drop-off.
IPC subclass composition
C22B (metal extraction and refining) dominates at 84.3% of the 83 records. C25C (electrolytic metal production) sits far behind at 15.7%, and smaller clusters in furnace detail (F27D), computational chemistry (G16C) and AI-based modelling (G06N) each cover 2.4% to 7.2% of records — small in absolute terms but notable as emerging classification patterns in an otherwise mature field.
Shares are the percentage of the 83 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Copper Smelting and Electrorefining with Eureka
This page is one run against one query. Ask Eureka your own question about copper smelting and electrorefining and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records in this landscape
AU2009251128A1 — Low intensity continuous copper smelting
The filing proposes a continuous, low-intensity smelting configuration built around two interconnected melt circulation loops joined by a siphon, intended to replace traditional Peirce-Smith converter operation. Non-oxygen-enriched air top blowing is applied in a non-splash mode against permanent linings of solidified copper matte, aiming to capture more of the energy content of high-sulphide feeds such as chalcopyrite while allowing continuous copper removal.Abstract text is truncated in the source record; full claims should be reviewed before relying on this summary.
View full record| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | CN111554353A | 氧气底吹炉铜熔炼过程参数在线预测方法 | 18 |
| 2 | CN101871050A | 消除硫化铜精矿火法冶炼过程产生磁性氧化铁炉结的方法 | 18 |
| 3 | US4802916A | Copper smelting combined with slag cleaning | 18 |
| 4 | US4802917A | Copper smelting with calcareous flux | 15 |
| 5 | WO2019219821A1 | Improvement in copper electrorefining | 14 |
| 6 | CN105624425A | 一种氧气底吹铜熔炼过程智能控制方法 | 12 |
| 7 | US5217527A | Process for continuous copper smelting | 12 |
| 8 | US5320662A | Process for continuous copper smelting | 11 |
| 9 | US5205859A | Apparatus for continuous copper smelting | 9 |
| 10 | US5320799A | Apparatus for continuous copper smelting | 8 |
Citation counts favour older records simply because they have had more time to accumulate citations within the searched corpus; treat them as a measure of influence, not of current relevance.
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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Browse MCP servers →What the numbers mean for a filing decision
Three patterns stand out once the assignee ranking, filing trend and IPC composition are read together.
A small group holds most of the claim space
The top five assignees combined account for 71 of the 83 records in scope — 85.5% of the field. The top ten extend that to 96.4%, leaving almost no filing activity outside a narrow set of established players. A new entrant is filing directly into occupied ground, not into open territory.
Activity has cooled since 2020
Filings peaked at 15 in 2020 and had fallen to 3 by 2022. That decline, read alongside the concentration figures, suggests the core smelting and electrorefining claim space is largely staked out rather than still being actively contested by new filers.
Smelting claims dominate over electrorefining claims
C22B (extraction and refining) covers 84.3% of records while C25C (electrolytic production) covers only 15.7%. Given the search scope explicitly includes electrorefining and cathode-purity language, that gap indicates electrorefining-specific process claims are comparatively less contested than smelting-stage claims.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to copper smelting and electrorefining, with the prior art for and against each one.
Who is filing, and where the gate sits
The assignee ranking covers 20 companies as returned by the data endpoint — not a top-50 or top-100 list. Filing activity is heavily concentrated at the top, with a long tail of single-digit filers below the tenth position.
One assignee dominates the ranking
The leading assignee holds 36 of the 83 records in scope, well ahead of the rest of the ranked field. Fifth place holds only 2 records, and tenth place holds 1 — the drop-off from the leader to the rest of the ranking is steep.
Inventor teams recur across filings
Ten co-assignee pairs appear in the dataset, with the strongest pairings each linked across 4 shared filings. That pattern points to stable inventor teams working repeat filings within the same organisation rather than shifting collaborations.
Filing offices are split across three regions
The United States, China and Finland each receive comparable filing volumes (13, 12 and 12 respectively), with the EPO, Canada and Japan following behind. No single jurisdiction dominates receiving-office activity the way one assignee dominates the ranking.
| Assignee | Recent year | YoY |
|---|---|---|
| Mitsubishi Materials Corporation | 0 | — |
| AURUBIS BEERSE | 0 | — |
| Metallo Belgium | 0 | — |
| Inco Limited | 0 | — |
| KIKUMOTO NOBUO | 0 | — |
| IIDA OSAMU | 0 | — |
| GOTO MOTO | 0 | — |
| Kunming University of Science and Technology | 0 | — |
Where to take this analysis
The dataset points to a mature, concentrated claim space with a few specific openings. The next steps depend on whether the goal is freedom-to-operate, competitive tracking, or identifying a defensible new filing.
Check freedom-to-operate against the leader
With one assignee holding 36 of 83 records, any new smelting or electrorefining process should be checked against that assignee's claim scope before further development spend.
Run an FTO scan in EurekaTrack the under-claimed branches
AI-assisted process prediction and computational-chemistry approaches to cathode purity appear at low volume (2.4% of records each) — worth monitoring for early movement.
Set up monitoring in EurekaReassess after the next publication cycle
Because publication lags filing by about 18 months, the 2025-2026 filing count will rise as more applications publish. Revisit the trend before concluding the field has gone quiet.
Explore full trend in EurekaCommon questions about this landscape
Within this 83-record dataset, a small number of assignees dominate: the top five combined hold 71 records, or 85.5% of the field, and the top ten hold 96.4%. The leading single assignee accounts for 36 records on its own, well ahead of the rest of the ranking. Anyone entering this space should expect to file close to, or directly against, this small group's existing claims rather than into open ground.
Filing activity peaked in 2020 at 15 records and had declined to 3 by the 2022 midpoint, indicating a flat-to-declining trend rather than growth. Because publication typically lags filing by around 18 months, the very latest years in the dataset will always look lower than they eventually turn out to be. Even accounting for that lag, the multi-year decline from the 2020 peak is a meaningful signal that the core claim space is not being actively expanded.
Metal extraction and refining (IPC class C22B) covers 84.3% of the 83 records in scope, making it by far the densest claim area. Electrolytic metal production (C25C), which covers electrorefining-specific processes, trails at 15.7%. Smaller classification clusters around furnace detail engineering, temperature measurement and computational or AI-based modelling each appear in a handful of records and represent comparatively lighter claim density.
The clearest openings sit in sub-areas classified outside the dominant C22B cluster: AI-assisted matte-grade or process-parameter prediction, computational-chemistry approaches to cathode purity, and furnace temperature monitoring each appear in only 2 of the 83 records. These are technically specific niches rather than broad claim territory, so a first filing there would need to target a defined process step or sensing method rather than a general smelting or electrorefining claim, which is already crowded.
AU2009251128A1 describes a continuous, low-intensity copper smelting configuration using two interconnected melt circulation loops joined by a siphon, designed to replace conventional Peirce-Smith converter operation with non-splash top blowing against permanent matte linings. Whether it blocks a specific new design depends on the exact claims, which should be reviewed in full rather than inferred from the abstract. Any team designing a continuous-flow or converter-replacement smelting process should review this filing's claim scope directly as part of freedom-to-operate work.
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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.