M ineral sand deposits, beach placer sands, and alluvial gold feeds contain complex mixtures of valuable heavy minerals—such as ilmenite (FeTiO₃), rutile (TiO₂), zircon (ZrSiO₄), garnet, monazite, and native gold—blended with abundant light silica quartz sand. Beneficiating these deposits requires separating mineral species based on physical property differences. While chemical flotation and magnetic separation play key roles in secondary refining, Spiral Gravity Separation represents the most cost-effective, eco-friendly primary concentration technology available.
A Spiral Concentrator is a static, vertical gravity separation unit consisting of one or more helical troughs wrapped around a central support column. Operating entirely without moving parts or chemical reagents, spirals rely on the combined interaction of gravitational force, centrifugal force, hydrodynamic drag, and differential settling velocities within a flowing film of mineral slurry.
Slurry conditioned to 30% to 45% solids by weight is delivered to the top feed box of the spiral trough. As the liquid stream accelerates down the curved helical profile under gravity, centrifugal force pushes the fluid film and suspended solids outward toward the outer perimeter of the trough. However, because different mineral species possess different specific gravities (Quartz = 2.65 SG vs. Ilmenite = 4.7 SG, Zircon = 4.65 SG, Gold = 19.3 SG), their hydraulic behavior inside the flowing film diverges dramatically.
Heavy mineral particles, possessing greater mass and higher specific gravity, sink quickly into the slow-moving boundary layer near the trough surface, where hydrodynamic drag is lowest. Experiencing minimal centrifugal force due to their reduced tangential velocity in the boundary layer, the heavy minerals migrate inward along the trough floor toward the central axis. Conversely, lighter silica quartz grains remain suspended in the fast-moving upper water film and are swept outward to the outer rim of the spiral stream.
Along the inner profile of the spiral trough, adjustable product splitters and discharge ports selectively divert the concentrated heavy mineral stream into a dedicated collector pipe. Meanwhile, middlings (partially liberated particles) are directed to a secondary re-treatment port, and clean silica sand tailings discharge cleanly at the outer bottom exit of the spiral.
Vyom Spiral Gravity Separators are engineered with computer-designed helical profiles, durable fiberglass construction, and ultra-smooth, polyurethane-bonded abrasion resistant inner linings. Available in single, twin, or triple start configurations per column, Vyom spirals maximize plant floor capacity while processing high slurry volumes with zero electrical power consumption on the spiral units themselves.
Configured into multi-stage Rougher, Cleaner, and Scavenger spiral banks, Vyom gravity separation circuits achieve heavy mineral recovery efficiencies exceeding 95%. By rejecting 80% to 90% of barren silica quartz tailings in the primary rougher stage, downstream drying, magnetic separation, and electrostatic processing costs are reduced exponentially. Spiral gravity concentrators offer mining operations a sustainable, chemical-free path to maximum mineral recovery.