Placer Gold Ore Processing Line

The process flow for placer gold ore beneficiation primarily includes the washing, screening, gravity separation, and concentration stages.

The methods and procedures for placer gold ore beneficiation are mainly divided into the following steps:

1. Washing Operation: This is a crucial preparatory step before the separation of placer gold, as the ore often contains a significant amount of weathered clay, which encapsulates the gold particles. The purpose of washing is to separate gravel, sand, and clay, and to clean the fine mud adhering to the gravel and the gold-bearing sand mixed within it. The washing process employs water flushing and mechanical agitation using equipment such as plane vibrating screens, trommel scrubbers, and cylindrical screens to liberate ore sand encapsulated within cemented lumps or mud aggregates.

   

2. Screening Operation: The primary goal of screening is to classify the washed placer gold ore, removing large gold-free gravel to improve gold recovery efficiency. This operation can eliminate 20-40% of waste rock and typically utilizes wet screening. Water is sprayed onto the screen surface to break up and disperse clay agglomerates, thereby enhancing screening efficiency.

   

3. Gravity Separation Operation: This is the key separation stage in placer gold processing, primarily utilizing gravity separation techniques. Equipment such as jig machines, shaking tables, and sluices are used to remove the majority of waste rock, thereby obtaining a rough gold concentrate. Gravity separation is economical and straightforward, suitable for gold due to its high specific gravity and coarse particle size. Through single or combined operations involving gravity separation, flotation, magnetic separation, and electrostatic separation, gold and various heavy minerals are further separated to achieve comprehensive recovery.

   

4. Concentration Operation: The concentration stage is an essential part of the placer gold beneficiation process. It significantly improves the recovery efficiency of gold and other heavy minerals, fulfilling the goal of comprehensive resource utilization. Depending on the specific type of placer gold deposit, concentration can be performed using various equipment and methods such as gravity separation devices and mercury amalgamation equipment, aiming to further increase the gold content.

The fundamental principle of placer gold ore beneficiation methods and flows is to separate the gold concentrate from other minerals based on the differences in specific gravity between the ore particles in the raw material.

Commonly used equipment for placer gold processing includes:

1. Washing and Screening Equipment: Trommel scrubber, trough washer, shaftless trommel screen, vibrating screen.

2. Gravity Separation Equipment: Sawtooth wave jig machine, centrifugal concentrator, pulsating sluice, flat sluice.

3. Concentration Equipment: 6-S shaking table, multi-deck shaking table.

4. Fine Flake Gold Recovery: Mercury plates are generally employed.

5. Amalgamation and Refining Equipment: Amalgamation barrel, mercury retort, gold melting furnace, graphite mold.