Gravity Concentration Equipment – Xinhai Mineral Processing EPC

Spiral Chute Separator (Gravity Spiral)

Wed, 17 Jun 2026 16:57:53 +0000

High-tonnage gravity separation with no moving parts

The spiral chute separator is one of the most economical gravity devices in a plant: a helical fiberglass trough that separates minerals by density and shape as slurry simply flows down it under gravity. With no motor and no reagents, it concentrates large tonnages of fine heavy minerals at very low operating cost, which is why spirals are deployed in large numbers across iron, chrome, mineral-sands and fine-gold circuits. Their simplicity also makes them well suited to remote sites with limited power and maintenance support.

How a spiral concentrates minerals

Slurry fed at the top spirals downward, and the combination of gravity, centrifugal force and the flowing water film stratifies the bed. Dense particles such as iron, chromite or gold settle and migrate to the inner edge of the trough, while lighter gangue is carried to the outer rim. Adjustable splitters near the discharge cut the band into concentrate, middlings and tailings. Because separation depends only on density and flow, the device is robust and almost maintenance-free, with no bearings or drives to service.

Where spirals fit

Iron and chrome: as roughers and cleaners on fine fractions; central to a chrome processing plant.
Mineral sands: recovering zircon, rutile and ilmenite from beach and dune deposits.
Fine gold and tin: as a high-tonnage pre-concentration stage ahead of a shaking table for final cleaning.

A typical spiral start handles roughly 1 to 8 tons per hour of solids in the fine size range, usually below about 2 mm down to fine sand. Multi-start assemblies pack several intertwined troughs on one column to multiply tonnage in a small footprint, which keeps a high-capacity plant compact. The fiberglass trough with a wear-resistant lining gives long service life, and with no power draw the cost per recovered ton is among the lowest of any separator.

Part of the gravity circuit

Spirals deliver a rougher concentrate that is normally polished by a table or centrifugal concentrator, so they are designed as one stage in a balanced circuit rather than a finished-product device. Xinhai supplies spirals standalone or within a complete gravity concentration plant under our EPC+M+O model. Read our gravity concentration guide or contact us with your feed size and mineralogy for sizing.

Gold Shaker Table (Gemini 6-S Concentrating)

Wed, 17 Jun 2026 16:57:53 +0000

The precision cleaner of the gravity circuit

When a gravity circuit needs a final, visually clean, smeltable concentrate, the shaking table is the device that delivers it. The Gemini 6-S style table uses a riffled deck, a controlled water film and an asymmetric back-and-forth stroke to fan out particles by density, so gold, sulfides and gangue separate into distinct bands you can split with adjustable cutters. Few other separators give you that level of visible, fine control over the final grade.

How a shaking table separates gold

Feed slurry spreads across the high corner of a slightly tilted deck. The fast-forward, slow-return stroke nudges heavy gold along the riffles toward the concentrate end, while cross-flowing wash water carries light gangue down the slope to tailings. Middlings band between the two and can be re-treated for extra recovery. Deck slope, stroke length, feed rate and wash-water volume are all tunable, which lets an operator dial in grade versus recovery for the specific feed rather than accept a fixed compromise.

Where the table sits in the flowsheet

As a cleaner on rougher concentrate from a centrifugal concentrator, jig or spiral chute, which is the most common duty.
As a primary concentrator for small alluvial or hard-rock free-gold operations.
For recovering tungsten, tin, tantalum and other heavy minerals where the density contrast is high.

A single deck handles roughly 0.1 to 1.5 tons per hour depending on size and feed, and multi-deck arrangements multiply throughput in a small footprint. Because the separation is visible, the table doubles as a process check; operators can see at a glance whether the upstream circuit is liberating and recovering gold properly, which makes it a useful diagnostic as well as a concentrator. Wear is limited mainly to the deck surface and riffle covering, so running cost is low and predictable.

Sized into your circuit

Tables are chosen by feed size, throughput and how clean the final concentrate must be, and they usually run after a rougher stage rather than alone. Xinhai supplies them individually or as part of a complete gravity concentration circuit under our EPC+M+O model. Read our gravity concentration guide or contact us with your feed details for sizing.

Gold Centrifugal Concentrator (Continuous)

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

Enhanced-gravity recovery of fine free gold

Conventional gravity devices struggle with fine and flaky gold below about 100 microns. A centrifugal concentrator solves this by spinning the slurry so heavy gold experiences many times normal gravity, letting it settle and lock into the bowl while light gangue is flushed away. It is the go-to unit for capturing liberated gold quickly, with no cyanide or other reagents, which makes it attractive where permitting or water chemistry rules out leaching.

How the continuous concentrator works

Feed slurry enters a rotating bowl lined with riffle rings. Fluidization water injected through the rings keeps the bed loose so dense gold particles migrate inward and pack, while quartz and other light gangue report to tailings. In a continuous unit, concentrate is discharged automatically on a timed cycle rather than requiring a full stop to rinse, so it runs in line with the plant without batch interruptions and needs little operator attention.

Where it fits in a gold flowsheet

Alluvial gold: as a primary recovery stage after screening to catch fine free gold.
Grinding-circuit scalping: on a cyclone underflow or mill discharge to pull coarse free gold out before it over-grinds or reaches leaching, where it can lock up in carbon.
Concentrate upgrade: ahead of a shaking table for a final clean, saleable concentrate.

Recovery of liberated fine gold is commonly in the 90 percent-plus range on suitable feed, with concentration ratios high enough to produce a smeltable product after table cleaning. Because there are no reagents and the wear parts are limited mainly to the bowl liner and fluidization ring, operating cost per ton is low and maintenance is simple. Fluidization water pressure is the key control variable, and it is set during commissioning to balance recovery against concentrate grade for your particular gold. Sizing follows your solids throughput and the gold size distribution rather than a single nominal rating.

Part of the gravity circuit

A centrifugal concentrator rarely works alone; it pairs with screening, classification and a cleaning table to deliver a finished concentrate. Xinhai supplies the unit standalone or as part of a complete gravity concentration circuit under our EPC+M+O model. Compare devices in our gravity concentration guide, or contact us with your feed data for sizing.