How does a gold jig machine work?
Saw tooth jig machine
A gold jig machine is a gravity separation device that recovers gold from alluvial or hard-rock ore by using vertical pulsating water to stratify particles by density. Gold (SG 19.3) sinks far faster than silicate gangue (SG 2.65), so it concentrates at the bottom while light waste washes away.
Basic Structure
Jig cell: Water-filled tank with a screen deck (often with a bed of steel shot/ragging).
Pulsation system: Rubber diaphragm or piston driven by an eccentric crank, creating up–down water pulses.
Feed & discharge: Slurry enters continuously; concentrate (gold) drops through the screen; tailings overflow.
jig machine manufacturer
Working Cycle (2 Phases)
Upstroke (Dilation/Lifting)
Diaphragm moves up, pushing water up through the screen.
The bed lifts and loosens; heavy gold lags and stays near the screen, while light gangue rises with the flow.
Downstroke (Stratification/Settling)
Diaphragm moves down, water flow reverses.
Gold settles much faster than gangue, working its way through the screen into the hutch (concentrate chamber).
Light waste settles slowly and is carried away as tailings.
Key Separation Forces
Gravity: Pulls dense gold downward more strongly.
Pulsation: Repeated lifting and settling enhances density-based sorting.
Hindered settling: In the crowded bed, gold's higher density dominates over size, leading to sharp stratification.
Main Operating Parameters
Pulse frequency: 300–600 cycles/min (higher for fines).
Stroke length: 10–25 mm (larger for coarser ore).
Bed depth: 100–200 mm (affects loosening and recovery).
Water flow: Sufficient to lift the bed but not wash out gold.
Applications & Performance
Best for: Coarse to medium gold (0.1–30 mm) in alluvial/Placer mining.
Recovery: 80–90% for +0.1 mm gold; less effective for ultra-fine gold (<0.04 mm).
Pros: High capacity, low cost, simple operation, robust design.
Cons: Requires pre-sizing (feed <6:1 width); tailings need further treatment for fines.
Flow Diagram Summary
Feed → Screen Deck → Pulsation (Up/Loose → Down/Settle) → Gold Concentrate (Bottom) + Tailings (Overflow)
