Placer gold ore beneficiation process

Placer gold deposits are formed in riverbeds and terraces downstream of gold sources through millions of years of geological movement and water transport. The gold particles in this type of ore are typically free, making them highly concentrated and ideally separated through gravity separation, without the need for crushing or grinding.

I. Overview of the gold placer beneficiation process

The process can be divided into four stages: classification and screening, gravity concentration, and table cleaning. The entire beneficiation process does not require the use of chemical agents and is environmentally friendly.

1. Cleaning and Screening

The mined placer gold ore first enters the drum screen for cleaning and screening. This process effectively separates dirt and fine sand, and transports the sand and gravel of different particle sizes to the appropriate gravity separation equipment for precise classification, laying the foundation for subsequent efficient gravity separation.

2. Gravity Concentration

Gravity concentration is the core of placer gold beneficiation. It achieves comprehensive gold recovery through three steps: roughing, scavenging, and concentrating.

Jig roughing: The jig generates a pulsed water flow that separates minerals of different specific gravities. High-density gold particles settle to the bottom and are collected, while low-density gangue is carried away by the water flow as tailings. This equipment is primarily used for roughing and concentrating placer gold.

Agitation chute scavenging: The reciprocating motion of the rubber belt bottom plate in the agitation chute creates a trembling water flow, causing fine gold particles to settle and concentrate in the gratings. Agitation chutes are highly effective for recovering fine gold particles and are used to recover fine gold from jig tailings.

Centrifugal concentrator scavenging: This equipment is particularly effective for capturing difficult-to-capture fine gold particles and is often placed after the agitation chute to improve overall recovery. Under the action of the powerful centrifugal force field generated by high-speed rotation, fine gold particles are thrown to the inner wall of the drum for enrichment due to their high specific gravity, and light minerals are discharged from the center.

3. Shaking Table Concentration

After concentrating in the jig, agitation chute, and centrifugal concentrator, the coarse concentrate is fed to the shaking table for final concentrating. The shaking table utilizes asymmetrical reciprocating motion on the bed and lateral water flow to separate gold from gangue, ultimately producing a high-grade gold concentrate.

II. This placer gold beneficiation process offers the following advantages:

1. High recovery rate: Jigs, agitation chutes, and centrifugal concentrators efficiently recover gold particles of varying sizes. A multi-stage gravity separation process ensures high recovery rates for gold from coarse to fine particles, covering a wide range of gold ore types.

2. High grade: The shaking table ultimately produces high-grade gold concentrate.

3. Pollution-free: The entire process utilizes physical separation methods, eliminating the use of chemical agents and ensuring environmental friendliness.