Spent Pot Lining Patents: Who Leads, Trends & White Space 2026
Spent Pot Lining and Hazardous Residue Patents
Concentrated at the top. The top 5 assignees hold 70.2% of all 47 records in scope, and the top 10 hold 97.9% — this field has almost no room left outside the ranked leaders. Filings rose to a peak of 8 in 2021, then fell to 2 by 2024 — a 75% decline over that three-year span. Because publication trails filing by roughly 18 months, the 2025 and 2026 counts shown are still incomplete and should not be read as a continuation of the decline.
- 1PYROGENESIS CANADA INC9
- 2NOVAFRIT INT8
- 3REYNOLDS METALS CO6
- 4KAISER ALUMINUM & CHEMICAL CORP5
- 5ALCAN INTERNATIONAL LTD5
See the full spent pot lining and hazardous residue analysis in Eureka
- The complete ranking, not just the top five
- Every IPC branch with its share of the corpus
- The most-cited records, and where claim space is still thin
Common questions on spent pot lining patents
Who holds the most patents on spent pot lining treatment?
The patent estate in this field is concentrated: the leading assignee holds 9 of the 47 records in scope, and the top 5 assignees combined account for 70.2% of all records. The top 10 push that share to 97.9%, leaving only a thin tail of single- or double-filing entrants. Most of the leaders are primary aluminium producers or specialist thermal-treatment licensors rather than general chemical companies, which reflects how tightly this technology is tied to smelter operations.
Is patent filing activity in spent pot lining treatment growing or shrinking?
Filing activity peaked at 8 records in 2021 and had fallen to 2 by 2024, a 75% decline over that three-year window. That said, publication typically lags actual filing by around 18 months, so the counts for 2025 and 2026 in this dataset are still filling in and should not yet be read as confirmation of a continued slowdown. 2024 is the most recent year that can be treated as reasonably complete.
What technology areas dominate spent pot lining patent claims?
Chemical recovery classes lead the field: C01F (alkaline-earth, aluminium and rare-earth compounds) appears on 57.4% of all 47 records, followed by C01B inorganic compounds at 46.8% and B09B solid waste disposal at 40.4%. Electrolytic production (C25C) and metal extraction (C22B) each cover 38.3% of records. Chemical detoxification claims under A62D are less common, at 29.8%, indicating most patented processes centre on recovering value from the residue rather than solely neutralising it.
Disclaimer. This analysis is based on Patsnap Eureka data drawn from a limited snapshot of global patent records and is provided for general information and reference only. Patent data carries inherent limitations — recent filings are under-counted because of publication lag, counts may be on a record or family basis, classification and applicant-name data may contain errors or duplicates, and the underlying search query defines the scope shown — so the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing here is an exhaustive prior-art, novelty, freedom-to-operate or validity search, nor does it constitute legal, financial or professional advice, and it should not be relied upon as such. Verify independently and review with qualified patent and legal professionals before acting on it.
Method: Filing trend and technology composition. Derived from a Patsnap search on Spent Pot Lining and Hazardous Residue covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish. Every share divides by all records in scope. Data: Patsnap Eureka. See the full landscape report.