One assignee holds 177 of the 239 records in scope, and together the top five assignees account for 93.7% of all records. That level of concentration means most of the core roll-construction and wear-surface claims sit with a small group of related corporate entities rather than being spread across many independent filers. Anyone assessing freedom-to-operate in this space should start with that leading portfolio before broadening the search.

Filing peaked in 2019 at 45 records and has declined since, with the last reliable comparison showing a drop from 25 filings in 2021 to 13 in 2024, a 48% fall. However, patent publication typically lags actual filing by around 18 months, so 2025 and 2026 figures in any dataset are still incomplete and should not be read as confirming a continued slowdown. The safest read is that activity cooled off its 2019 peak through 2024, with the more recent trend still unresolved.

The dominant IPC class is B02C (crushing, grinding and pulverising), covering 94.1% of the 239 records in scope, which confirms most filings address the grinding mechanism directly. Smaller but recurring clusters appear in B30B (presses, 9.2%), C22C (alloys, 5.0%), B22F (powder metallurgy, 4.6%) and B23P (metal working, 4.6%), reflecting roll-surface material science and construction techniques. Because a single patent can carry multiple IPC codes, these shares add up to more than 100% of the record total.

The gap between the dominant B02C class and its much smaller neighbours — B30B presses, C22C alloys, B22F powder metallurgy — suggests roll-surface material formulations and press-integration approaches carry lower filing density than the core grinding-mechanism claims. Process-optimisation approaches, like sensor-based monitoring of roller throughput and recycle ratio, also represent a comparatively newer and less crowded angle. Any first claim in these areas should still be checked against the leading assignee's portfolio, since that group's filings can extend into adjacent construction and material claims even when they are not the majority of their portfolio.

WO2024182851A1, filed by IDOBA PTY LTD and published 2024-09-12, claims systems and methods for monitoring HPGR roller throughput and recycle ratio with proxy sensors, then using that data to justify rejecting low-grade ore and increase fresh-feed capacity. It is a process-optimisation and software/data claim layered on top of existing HPGR hardware, not a claim on roll construction, wear materials, or the physical grinding mechanism itself. A hardware developer building rolls or wear surfaces is unlikely to be blocked by it directly, but anyone building sensor-driven throughput optimisation software for HPGR circuits should review its claim scope closely.