Classifiers & Hydrocyclones – Xinhai Mineral Processing EPC

High Weir Spiral Classifier for Grinding Circuits

Wed, 17 Jun 2026 16:57:54 +0000

The high weir spiral classifier is a mechanical size-classification device that works in closed circuit with a grinding mill. Its job is to split mill discharge into a coarse fraction that needs more grinding and a fine fraction ready for concentration, ensuring the downstream process receives a consistent particle size.

How it works

Slurry enters an inclined tank where heavier, coarser particles settle to the bottom. A slow-rotating spiral rakes this settled sand up the slope and discharges it at the top, where it returns to the ball mill for regrinding. The lighter, finer particles stay in suspension and flow over the weir at the lower end as overflow. The high weir design positions the overflow lip above the spiral center, giving a larger settling area and a finer, more controlled overflow than a low-weir or submerged design, which makes it well suited to fine-grinding circuits.

Returns coarse sand to the mill, preventing over-grinding and stabilizing the circuit.
High weir gives finer overflow control for metallic-ore grinding.
Simple, robust mechanics with low maintenance and easy operation.

Spiral classifier vs. hydrocyclone

Mechanical classifiers and hydrocyclones do the same job differently. The spiral classifier is gravity-driven, gentle, easy to operate, and visible to the operator, but it has a larger footprint and a coarser practical cut size. A hydrocyclone is compact, makes finer cuts, and handles high tonnage in a small space but needs pump pressure and more wear management. Our spiral classifier vs hydrocyclone guide compares them in detail.

Sizing and integration

Classifier selection follows the mill it serves: required sand-return tonnage, target overflow fineness, and slurry density set the spiral diameter and tank length. As an OEM manufacturer, Xinhai offers single- and double-spiral units across a range of diameters and matches the unit to the wet ball mill it serves rather than offering one fixed size; the double-spiral design roughly doubles sand-return capacity for a given diameter. See the full classifiers and hydrocyclones range, and ask about complete grinding-classification circuits through our EPC+M+O service.

Send your mill size, target overflow fineness, and tonnage and we will recommend a spiral configuration and budget via our contact page.

Hydrocyclone Separator | Cyclone Classifier for Slurry

Wed, 17 Jun 2026 16:57:54 +0000

The hydrocyclone, or cyclone separator, is a compact, no-moving-parts classifier that uses centrifugal force to split a slurry by particle size. It is the high-capacity counterpart to the mechanical spiral classifier and dominates modern grinding circuits where a fine, precise cut is needed in a small footprint.

How it works

Slurry is pumped under pressure into the cylindrical top section through a tangential inlet, setting up a fast spiral flow. Centrifugal force throws coarse, heavy particles to the wall, where they spiral down the cone and exit as underflow (the coarse, dense product). Finer, lighter particles migrate to the low-pressure core and rise out through the vortex finder as overflow (the fine product). With no motor or moving parts on the cyclone itself, separation is driven entirely by feed pressure and geometry.

Cut size set by cone diameter, spigot and vortex-finder sizing, and inlet pressure.
Very high capacity per unit volume; small footprint versus mechanical classifiers.
No moving parts on the cyclone; wear-resistant liners protect against abrasion.
Easily clustered into radial groups to scale tonnage.

Cut size and wear

Smaller-diameter cyclones make finer cuts but lower throughput, so high tonnage at a fine cut is met by clustering many small units in a radial manifold. Inlet pressure, typically held in a stable band, also shifts the cut. The main consumables are the liners; Xinhai supplies rubber, polyurethane, or ceramic liners chosen to your slurry abrasiveness to control wear-part cost. As an OEM manufacturer we configure single units or clusters to your duty rather than offering one fixed model.

Cyclone vs. spiral classifier

A hydrocyclone wins on footprint, cut fineness, and capacity but needs a feed pump and active wear management; a high weir spiral classifier is simpler, gentler, and easy to watch but coarser and larger. Our spiral classifier vs hydrocyclone guide compares both. Hydrocyclones close the loop on a wet ball mill and prepare feed for downstream concentration and dewatering stages. See the full classifiers and hydrocyclones range, and ask about full circuits through our EPC+M+O service.

Send your slurry data, target cut size, and tonnage and we will recommend cyclone size or a cluster with liner choice and budget via our contact page.