Zinc roasting, leaching and electrowinning patents: mapping who holds the process ground
43.6% concentration. The top 5 assignees alone account for 206 of the 472 records in scope — filing here is unusually concentrated at the very top. Filings peaked at 15 in 2017 and have not returned to that level, but the trend is not a simple decline: 2021 to 2024, the last year that can be treated as complete, rose from 3 to 4 filings — a 33% increase. Years after 2024 will fill in further as publication catches up with filing.
- 1OUTOTEC OYJ78
- 2OUTOKUMPU OY36
- 3NORANDA INC36
- 4SHERRITT INC35
- 5TECH REUNIDAS SA21
See the full zinc roasting leaching and electrowinning 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 about this landscape
Who holds the most patents in zinc leaching and electrowinning?
One assignee leads clearly with 78 of the 472 records in this dataset, more than three times the fifth-placed assignee's 21 records. The top 5 assignees combined hold 206 records, or 43.6% of the entire field, and the top 10 extend that to 60.6%. This is a steeply concentrated landscape rather than one with many evenly matched competitors, so any competitive analysis should start by mapping the leader's specific claim scope before looking at the long tail.
What is the most common patent classification in this field?
C22B, covering metal extraction and refining, appears in 88.8% of all 472 records — by far the dominant classification. C01G (compounds of other metals) and C25C (electrolytic metal production) follow at roughly a quarter of records each, reflecting the two other technical centres of the process: leaching chemistry and cell-house electrowinning. Because a single record can carry several IPC classes, these shares add up to well over 100% and should not be read as a breakdown of the whole field into non-overlapping parts.
Is filing activity in zinc hydrometallurgy patents increasing or slowing down?
Filings peaked in 2017 at 15 in a single year and have not returned to that level since, but the more recent complete-year data shows growth, not decline: filings rose from 3 in 2021 to 4 in 2024, a 33% increase over that span. Because patent publication lags filing by roughly 18 months, the years closest to the present in any dataset understate actual filing activity, so it would be premature to read 2025 or 2026 figures as a slowdown.
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 Zinc Roasting Leaching and Electrowinning 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.