What are spiral classifiers used for?
A spiral classifier separates particles in a settling pool and mechanically conveys the settled coarse fraction. It can return coarse solids to a mill while finer material leaves with the overflow.
How it works
Particles settle at different rates according to size, density and slurry conditions. A rotating spiral lifts settled solids along an inclined trough. Pool area, weir arrangement and conveying capacity must be selected together.
When to consider it
Consider a spiral classifier for an appropriate coarse classification or sand-handling duty where the layout permits an inclined trough. State both the overflow target and the amount of solids to be conveyed.
Application limits to check
Fine cut targets, density differences and a restricted footprint can favor other arrangements. Nominal spiral diameter alone does not establish classification performance or sand-handling capacity.
Selection data for a useful quotation
These are enquiry inputs, not specifications of a single model. Include measured values, units and the expected operating range; flag anything still to be tested.
| Input | What to provide |
|---|---|
| Feed | Solids throughput, size distribution and mineral density |
| Slurry | Concentration, viscosity, temperature and water quality |
| Separation | Overflow size target and permitted coarse carryover |
| Sand duty | Settled solids rate, moisture target and return elevation |
| Geometry | Pool area, weir arrangement, slope and available footprint |
| Mechanical scope | Spiral wear, bearing protection, lifting and drive |
Compare the complete duty
A hydrocyclone uses pressure-driven flow and usually has a different footprint and operating sensitivity. A spiral classifier combines settling with mechanical transport; compare both classification and coarse-solids return requirements.
Before accepting a supplier proposal
- Request separate checks for overflow duty and spiral conveying duty.
- Review the lifting arrangement, lower-bearing protection and wear replacement.
- Confirm trough dimensions, elevations and sampling points in the mill layout.
Buyer questions about spiral classifiers
What is the spiral's main job?
It conveys material that has settled in the pool. The settling zone provides the classification function.
Can a classifier replace a mill?
No. It separates streams rather than grinding the ore. Coarse material may be returned to a mill for further reduction.
Which data determine the overflow?
Feed size, solids density, slurry properties, water flow and pool geometry all contribute. Provide more than only tonnes per hour.
Technical reference
Xinhai: official equipment and technology description ↗
The source provides technology context. The selection checklist is KMS Industrial editorial guidance; manufacturer models and performance figures are not KMS specifications.