Working Principle of Gold Ore Flotation Machine

The gold ore flotation process is a critical step in mineral processing, aiming to separate gold-bearing minerals from gangue through physicochemical methods to enhance concentrate grade and recovery rate. The self-suction flotation machine, as an energy-efficient flotation equipment, has been widely adopted in gold ore processing. This article elaborates on its working principle and technical advantages based on structural design and operational workflow.

1. Core Structure of Self-Suction Flotation Machine

The machine consists of an impeller, stator, tank, air inlet, motor drive system, and foam collection device. Key components include:

1.    Impeller: Driven by a motor at high speed (500–1200 rpm), it agitates the pulp and generates negative pressure to suck air.

2.    Stator: Positioned around the impeller, it stabilizes fluid flow, reduces turbulence, and ensures uniform bubble distribution.

3.    Tank: Serves as the main container, divided into feeding, reaction, and separation zones.

4.    Air Inlet: Automatically draws atmospheric air via negative pressure without external compressors.

2. Dynamic Mechanism of Flotation Process

The workflow comprises three stages: bubble generation, mineral attachment, and separation.

1. Bubble Generation and Dispersion
High-speed rotation of the impeller creates a turbulent flow field. A low-pressure zone formed beneath the impeller draws air through the inlet. The air is sheared into fine bubbles (0.5–2 mm diameter) and mixed with pulp. The impeller’s design critically affects bubble size and density.

2. Mineral-Bubble Attachment
Hydrophobic gold particles, modified by reagents (collectors and frothers), attach to bubbles via van der Waals forces and surface tension. Hydrophilic gangue remains in the pulp. Reagent addition sequence (collectors first, then frothers) optimizes this process.

3. Bubble-Mineral Separation and Enrichment
Mineralized bubbles rise to form a froth layer, stabilized by the stator. The froth is scraped as concentrate, while tailings settle at the tank bottom. Multi-stage cleaning further purifies the concentrate.

3. Technical Advantages

Compared to conventional aerated flotation machines, the self-suction type excels in:

1.    Energy Efficiency: Eliminates external compressors, reducing energy consumption by 10–15% (5.6 kW·h/t).

2.    Superior Bubble Quality: Finer, uniformly distributed bubbles enhance fine gold recovery.

3.    Adaptability: Suitable for sulfide/oxide ores and complex paragenetic minerals, especially for micro-sized (<20 μm) encapsulated gold.

4.    Operational Flexibility: Simple maintenance and adjustable parameters (e.g., impeller speed) for varying ore types.

4. Practical Performance

In a 1000 t/d gold plant using JUF-4 machines, the concentrate grade improved from 37.8 g/t to 40.4 g/t, recovery increased from 85.6% to 88.4%, and tailings gold loss decreased by 0.13 g/t. Annual revenue increased by ¥13.5 million, with 8% lower reagent costs.