Gold Gravity Separation Line

Process Introduction

The gold gravity separation line is a traditional mineral processing technique for separating gold based on differences in mineral density. It utilizes equipment such as jigs, shaking tables, spiral chutes, and centrifugal separators to recover coarse-grained free gold (>0.1 mm) through the use of gravity, water flow, or centrifugal force. This method offers the advantages of low cost and no chemical pollution. However, it has a relatively low recovery rate for fine-grained gold (<0.01 mm), often requiring the combination of flotation or cyanide leaching processes. This method is particularly suitable for placer gold deposits and coarse-grained vein gold deposits. The application of modern centrifugal technology has further improved the recovery efficiency of fine gold, making it one of the preferred environmentally friendly gold ore processing solutions.

Workflow Introduction

(1) Core separation principles
Density differences: The density of gold (19.3 g/cm³) is significantly higher than that of common gangue minerals (quartz 2.65 g/cm³, feldspar 2.6 g/cm³), making gold particles more likely to settle in a gravitational field.

Particle size and shape: Free gold typically occurs in flake or granular form, making it easier to separate from lighter minerals; however, if gold is encapsulated or too fine (<0.01 mm), gravity separation efficiency decreases.

(2) Separation media
Water flow or air flow: Utilizes fluid dynamics (e.g., lateral water flow in a shaking table, pulsating water in a jig) to enhance density separation.

Centrifugal force field (e.g., centrifugal concentrator): Enhances gravity through high-speed rotation to improve the recovery rate of fine gold particles.

Main gravity separation equipment

（1）Shaking table
Principle: Horizontal water flow and reciprocating motion on the bed surface cause minerals to stratify according to density and particle size, with gold concentrating in the concentrate zone.

Applicable particle size: 0.074–2 mm (medium to fine-grained gold).

Advantages: High sorting accuracy, with concentrate grades reaching up to 1,000 g/t.

Disadvantages: Low processing capacity (0.5–2 t/h), requiring multiple units to be operated in parallel.

（2）Spiral chute
Principle: Slurry slides down the spiral chute, and centrifugal force and gravity work together to separate the particles.

Applicable particle size: 0.02–0.1 mm (fine gold particles).

Advantages: No power required, simple maintenance, suitable for low-grade placer gold.

Disadvantages: Low enrichment ratio, requires subsequent refining.

（3）Gold Jig
Principle: Periodic water flow pulsations cause heavy minerals (gold) to settle, while light minerals are washed away.

Applicable particle size: 0.5–10 mm (coarse gold).

Advantages: Large processing capacity (5–50 t/h), suitable for coarse selection of placer gold.

Disadvantages: Low recovery rate for fine gold (<30%).

(4) Centrifugal mineral separator
Principle: High-speed rotation (60–300 G) strengthens the gravitational field to capture fine gold particles.

Applicable particle size: <0.1 mm (ultra-fine gold particles).

Advantages: Recovery rate can reach over 90%, replacing traditional sluice boxes.

Disadvantages: Expensive equipment and high energy consumption.

Process Advantages:

• Environmentally friendly and pollution-free:
  No chemical agents are required throughout the entire process, eliminating the use of toxic substances such as cyanide or mercury. Tailings treatment is simple and meets green mining standards.
• Low-cost and high-efficiency:
  The equipment has a simple structure, with investment and operational costs significantly lower than those of flotation or leaching processes. It is particularly suitable for small and medium-sized mines and gold recovery from sand.
• High recovery rate for coarse-grained gold:
  Recovery rates for free gold particles larger than 0.1mm can reach 70% to 90%, avoiding metal loss caused by over-grinding.
• Energy-efficient and low-consumption:
  The process primarily relies on gravity or water flow sorting, resulting in significantly lower energy consumption compared to combined processes involving crushing, grinding, and chemical extraction.

Service Support