Hydrocyclone Feed Slurry Density Measurement

A hydrocyclone separates particles through a combination of feed conditions and equipment geometry. Density is one important feed variable, but it is not the whole process. A continuous trend can show changes in the slurry delivered to the cyclone battery and provide an earlier signal than intermittent samples alone.

Start by defining the operating decision: stabilising feed conditions, investigating classification behaviour, coordinating water addition or monitoring a regrinding circuit. Do not claim that density alone controls cyclone performance.

• Feed pressure and pump operating state
• Volumetric flow where measured
• Ore and particle-size changes
• Water addition and dilution points
• Cyclone configuration, duty and active units
• Overflow and underflow observations
• Time-matched sample and laboratory results
• Start-up, shutdown and water-flush states

Rhosonics reports density measurement on cyclone feed and grinding-mill feed at an Agnico Eagle regrinding circuit, where the stated objectives included a consistent cyclone-feed target and stable mill-feed density.

A separate Brazilian gold-processing case describes an SDM side-mounted to the hopper feeding hydrocyclone classification, with commissioning and calibration compared against laboratory analysis. These cases help frame the measurement task; they do not establish a universal control strategy.

Classification depends on more than feed density. Pressure, flow, particle-size distribution, ore characteristics, cyclone condition and operating configuration also matter. A landing page should not promise recovery, throughput or energy improvements without site evidence.

Use density as a continuously available process variable within a wider control and diagnostic plan. Define what operators should check when the trend moves and when the signal should be treated as invalid.

1. Name the process problem. Distinguish unstable density from pressure, flow, ore or equipment issues.
2. Map the circuit. Mark mill discharge, sump, water addition, pump, feed manifold, sampling and cyclone locations.
3. Choose a representative point. Confirm full-pipe conditions, access, wear, pressure and safe isolation.
4. Define the evidence set. Align density, pressure, flow, samples and cyclone observations in time.
5. Agree acceptance criteria. Test normal and relevant transition conditions before using the signal in control.
6. Document operator response. State what to inspect or adjust and which interlocks remain independent.

See the broader mining and mineral-processing guide and the strengthened grinding-circuit article.

Is cyclone-feed density the same as mill-discharge density?

Not necessarily. Circuit layout, sump mixing and water additions can change the stream between measurement points. Name and document the exact location.

Does a stable density guarantee good classification?

No. It removes one source of variation but pressure, flow, particle size, cyclone condition and configuration still need attention.

How should the online reading be checked?

Use a documented, representative sampling method and align the sample time with the online measurement and process residence time. Compare across more than one operating point.

Reviewed 10 September 2026 against the Rhosonics Agnico Eagle regrinding-circuit case, gold-processing classification case, current SDM ECO product information and operating manual. Case conditions and outcomes must not be generalised to another plant.

Send PMA the circuit drawing, proposed measurement point, slurry range, pipework, pressure and flow information, water-addition points, sample method and the decision operators need to make.