Precious Metal Electrowinning Patents: Leaders & Trends 2026
Precious metal electrowinning and refining patents: who files, what routes they claim, and where the field is still open
77 records, one clear leader. The ranked leader sits at 16 records against a fifth-place assignee at 8 and a tenth-place assignee at 2 — a steep drop-off rather than an even spread. Filings ran at 6 in 2017 and reached a peak of 7 in 2021. By 2024 — the most recent year that can be treated as complete, given the roughly 18-month lag between filing and publication — the count had eased to 6, a -14% move over that three-year span. Years after 2024 will keep rising as more publications land; they should not be read as a slowdown yet.
- 1PRECIOUS METALS RECOVERY16
- 2PRIOR ENG SERVICES15
- 3ENVIRO METALS LLC13
- 4ASARCO LLC12
- 5BROMINE COMPOUNDS8
See the full precious metal electrowinning and refining 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 this landscape
Who are the leading patent holders in precious metal electrowinning and refining?
This dataset ranks 19 companies by record count, with the top-ranked assignee holding 16 records against a fifth-place company at 8 and a tenth-place company at 2. That drop-off means the field has one clearly dominant filer rather than several evenly matched competitors. Names include process-equipment and refinery operators alongside specialty chemical suppliers, reflecting that refining patents come from both equipment builders and the refineries that run the equipment.
Is patent filing in precious metal refining increasing or decreasing?
Filings peaked at 7 in 2021 and eased to 6 by 2024, a -14% change over that three-year span — a modest pullback rather than a collapse. Because publication typically lags filing by around 18 months, the 2025 and 2026 figures in any chart are still incomplete and will rise as more records publish. Read the trend as cooling slightly from a 2021 high point, not as a field in decline.
What does the Miller process versus the Wohlwill process mean for patent strategy?
Both terms sit inside the search scope for this landscape, and the vast majority of records classify under C22B, the general metal extraction and refining subclass, rather than under the electrolytic-production subclasses C25B or C25C. That imbalance suggests most patent activity addresses the chemical and mechanical steps around these processes — feed preparation, slime treatment, purification chemistry — rather than the electrolytic step itself, which appears comparatively under-claimed in this corpus.
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 Precious Metal Electrowinning and Refining 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.