Thickener circuits are solid-liquid separation processes, concentrating solids in the underflow whilst recovering water (or the aqueous phase) in the overflow. The throughput of the thickening process depends heavily on how quickly and completely the solids in the slurry can settle in the thickener.

How quickly solids should settle to achieve sufficient separation, depends both on the throughput (or feed) rate and the required product quality (mainly underflow density and/or overflow clarity). This required settling rate constantly shifts, as changing feed rates change the rise rate (upflow of slurry) in the thickener. Additionally, the required underflow density and/or overflow clarity might also change. This means that the settling rate required to achieve the Thickener performance objectives also changes.

Operators and Metallurgists are completely unaware of how the settling rate of their thickener(s), and therefore their flocculant dose, need to change in real-time. This leads to reduced thickener performance: either not achieving the target underflow density, overflow clarity - or not recovering as much water as it can, at the desired throughput.

Our Solution's solution to this challenge is the Minimum Settling Rate Virtual Sensor, with its accompanying Alert.
The Thickener Application determines the minimum settling rate in real-time, based on the thickener geometry, the feedwell design and the quantity and properties of the feed material. This is delivered in as a Virtual Sensor, which serves as the minimum constraint for the actual settling rate (PV) of a thickener.

Additionally, this Virtual Sensor can guide the real-time selection of the flocculant dose setpoint from flocculant test work - either periodically by human consultants/operators, or real-time by the Thickener Application (more on this soon!).


This visibility on the Minimum Settling Rate allows Operators to:

  • Quickly detect when their actual settling rate is not sufficient for the required separation.

  • Keep their thickener circuit running at its required throughput, and overflow and underflow specification.

This means a thickener circuit that is more consistently achieving its performance KPIs, contributing to delivering on-spec concentrate and/or tailings streams.

For more info, please do reach out to us via Intercom. We'd be happy to help!

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