The ranked assignee list covers 42 companies built from 114 records, with the top-ranked filer holding 13 records and the fifth-ranked holding 9. The leading five together account for 47.4% of all records, and the leading ten account for 72.8%. That means competitive tracking should focus on this group rather than trying to monitor the full 42-company list, since filing activity drops off sharply after the tenth position.

In this dataset the two terms are searched together because filings often blur the distinction: a thickener is typically claimed around concentrating solids into a dense underflow, while a clarifier is claimed around producing a clear overflow liquid. Many records claim both functions in one vessel, particularly high-rate thickener designs, so IPC classification (chiefly B01D for separation processes) is a more reliable filter than the product name used in the title.

Control-loop claims for underflow density and rake torque sit predominantly in B01D (separation processes), which touches 96.5% of the 114 records in scope. A substantial secondary cluster falls in C02F (water and wastewater treatment) at 43.9%, reflecting that many control claims are framed around treated-water quality rather than mechanical torque alone. Searches limited to a single class will miss real prior art in the other.

Paste thickening for tailings is part of the metals-extraction crossover captured under IPC C22B, which reaches 10.5% of the 114 records in scope — a meaningful but minority share compared to the core separation-process claims. Filing overall peaked in 2018 at 18 records and dipped to zero at the 2022 midpoint before recovering, so any tailings-specific view should be read against that broader recovery pattern rather than assumed to be growing independently.

The clearest gaps sit in branches with thin representation relative to the dominant separation-process core: flocculant polymer chemistry (C08F reaches only 11.4% of records), overflow clarity sensing tied to feedback control, and crossovers into crushing/grinding pre-treatment (B02C, 9.6%) and pulp/paper compositions (D21H, 15.8%). These are areas where the mechanical vessel claims are dense but the adjacent chemistry or sensing claims are comparatively sparse, which is where a first claim is more likely to clear prior art.