A replacement flotation rotor is ordered against nine measured values: rotor outside diameter, rotor height, shaft diameter and taper, keyway detail, bolt circle with count and size, stator clearance, drive interface, rotation direction, and material grade. Measure the shaft and the stator, not the worn rotor faces, because the worn surfaces no longer carry the original geometry. Six values decide fit. The other three decide whether the part performs once it's in.

Key Takeaways

· Model numbers identify the cell family but don't guarantee current geometry; cells get revised without the plate changing.

· Six dimensions decide fit: diameter, height, shaft size and taper, keyway, bolt circle, clearance.

· Worn rotor faces lie; measure the shaft, the stator and the seat instead.

· Tolerance stack, balance grade and rotation direction decide whether the part works, not just whether it fits.

· Send photographs with a scale, the wear map, and the old rotor or a rubbing where possible.

Summary Table

Definition

A flotation rotor (impeller) is the rotating part of a mechanical flotation cell that disperses air into the pulp and lifts solids into the froth zone. It mounts on a shaft through a keyed or tapered hub, runs inside a stationary stator (disperser), and its geometry — diameter, blade profile, height and running clearance — sets the cell's aeration and circulation characteristics. A replacement rotor must reproduce that geometry closely enough to preserve the clearance the cell was designed around.

Working Principle

The rotor-stator gap decides both shear and circulation; both parts are measured, not guessed.

The rotor spins, slurry is drawn up through the central passage and flung outward past the stator blades, where air dispersed from the shaft or the air intake is sheared into fine bubbles. Those bubbles attach to hydrophobic particles and carry them into the froth layer. The mechanism is described well in the Rotor & Stator in Mechanical Flotation Cells: The Heart of Efficient Mineral Flotation guide, but the short version is simple: the gap around the rotor governs both bubble size and circulation, and the rotor's dimensions govern the gap.

Feed preparation matters as much as the cell itself. Particles are sized ahead of flotation by grinding and classification, and the Hydrocyclones setting the feed size distribution determine how much work the rotor has to do. A cell fed coarser slurry wears its rotor faster and recovers less.

Benefits

Getting the dimensions right delivers four returns.

The part seats on the first lift. No grinding, no shimming, no re-quoting during a shutdown.

Recovery holds. A rotor with the right clearance reproduces the aeration the cell was tuned for; recovery loss after a change-out is usually a clearance problem wearing the new part's name.

Wear life matches the duty. The right material grade, chosen against the slurry, gives predictable replacement intervals instead of surprises. The Flotation Cell Rotor and Stator Wear Parts: How They Control Recovery, Flow and Maintenance Cost guide maps where the metal goes and why.

Bearing life is protected. A balanced rotor doesn't load the shaft bearing, and the gearbox output lasts as long as it should.

Applications

Rotor dimension discipline applies across the common mechanical cell families. Plants running XJK Flotation Cell/Machine units, SF Flotation Cell/Machine circuits and XCF/KYF Flotation Cell installations all face the same problem: the same nominal model has been built with different hub details across production years, and the nameplate doesn't say which vintage is installed.

Copper concentrators, gold circuits, and industrial mineral flotation all qualify. Where the cell is one of many in a bank, dimension discipline pays twice — standardised dimension sheets let one spare rotor serve several cells instead of one.

Material Comparison

Material and geometry interact. A thicker lining changes the effective diameter, so the dimension sheet must state lining thickness, not just nominal size. The Flotation Impeller & Stator page lists grades against duty.

Application Comparison

A rotor replacement is not a pump impeller replacement, but the ordering discipline transfers. Plants that measure shafts before ordering Pump Wear Parts already know the failure mode: a part quoted from a model number that arrives with the wrong hub. Flotation adds one twist — the running clearance to the stator is a process variable, not just a mechanical one, so the dimension sheet must include the gap the cell actually runs, checked with the rotor seated and centred.

Industry Application Matrix

Selection Guide

Concentrator expansions push more tonnes through existing cell volumes.

Choose the supplier on three things, in this order. First, whether they ask for measurements before quoting — a quotation without questions is a guess with a price. Second, whether they hold the tolerances your clearance stack needs and can state them in writing. Third, whether they can match material to duty instead of defaulting to the grade they stock. The Flotation hub lists the cell families and spares in one place for comparison.

Procurement Guide

The order package has five items: the dimension sheet with units and reference edges, the wear map of the old rotor, photographs with a scale in frame, the cell model and serial where a plate exists, and the material preference with justification. Suppliers who work from samples — the old rotor itself, or a rubbing of the shaft end — quote faster and hit closer. The Flotation Spares (Rotor & Stator) page documents the drawing and sample inputs accepted.

Buy the stator review in the same order. A new rotor inside a worn stator gives a gap that's too wide, and the recovery loss arrives wearing the new part's name.

Failure Analysis

Most premature rotor failures trace to one of five causes.

· Chemical or cavitation attack beyond the material grade's duty.

· Wrong clearance — too tight wears both parts, too loose kills shear.

· One-sided wear from a centring fault, inherited by the replacement.

· Hub fatigue from rocking on a worn keyway or undersized bolt circle.

· Unbalanced operation loading the shaft bearing until failure looks like a bearing problem.

The pattern worth noticing: only the first cause is the material's fault. The other four are measurement and installation faults, and all four are preventable with the dimension sheet described above.

Maintenance Guide

A one-sided wear map points at centring, not at the fabricator.

Record a baseline at installation: clearance, runout, balance record, and the date. Trend rotor wear at fixed points monthly, and check the wear map for one-sided loss every quarter. Keep the dimension sheet with the spares file, updated whenever a cell is revised — the sheet that saved you this year is the one that saves you next year. Keep one spare rotor per cell bank on site, with the hub fitted and balanced, ready to lift.

Case Study

A concentrator running three flotation banks of the same nominal model ordered rotors by model number for years, and every second replacement needed fitting work during the outage. The plant measured the three banks properly the following shutdown: two matched the plate, one had a different sha