Cyanide Free Gold Processing Patents: Who Holds the Ground and Where It's Open
Filing has gone quiet since the 2021 peak. The dataset shows a -100% swing from 2021 (13 records) to 2024 (0), the last year publication lag lets us treat as complete — a sign the field's early claim space is settling, not that interest has stopped. Records climbed from 9 in 2017 to a peak of 13 in 2020, sustained through 2021, then declined to 0 by 2024 — the complete run the -100% figure is drawn from. 2025 and 2026 are omitted from any growth reading because publication lag means they are still incomplete.
- 1PLACER DOME TECHN SERVICES29
- 2BARRICK GOLD CORPORATION22
- 3EXCIR WORKS CORP22
- 4VALE INCO10
- 5PIVAZYAN ARMAN7
See the full cyanide free gold processing 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 cyanide-free gold processing patents
What are the main cyanide-free gold leaching methods covered by patents?
The dataset is dominated by thiosulfate leaching, often catalysed with copper or carbon, alongside glycine leaching as a secondary chemistry. Supporting process steps — resin adsorption to recover dissolved gold, effluent detoxification, and reagent regeneration — appear as claim elements around the core leaching step rather than as standalone technologies. Metal extraction and refining (IPC C22B) appears in 98.0% of the 101 records in scope, confirming this is treated as an extraction-chemistry problem first.
Who holds the strongest patents in cyanide-free gold processing?
The most-cited records in this dataset are a cluster of related US filings on thiosulfate leaching of precious metal-containing materials, each cited 20 or more times, with the oldest at 33 citations. In terms of filing volume, the ranking is led by one company with 29 records against a field of eleven ranked companies total, with a steep drop to single-digit counts by fifth place. High citation counts reflect influence on later drafting more than current commercial dominance, since citation counts favour older filings.
Is patent filing activity in this field growing or shrinking?
On the years complete enough to trust, activity is shrinking: filings fell from a sustained peak of 13 records in 2020-2021 to zero in 2024, a -100% change over that span. Because publication lags filing by roughly eighteen months, 2025 and 2026 figures are still filling in and should not be read as evidence of a further decline. The honest read is that the initial wave of claim activity around 2020-2021 has passed, and it is too early to say what comes next.
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 Cyanide Free Gold Processing 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.