Gold mining remains one of the world’s most valuable extraction industries, with alluvial gold deposits presenting both opportunities and challenges for miners. Ghana, with its rich mineral resources, has become a significant hub for gold mining operations in West Africa. One of the most challenging aspects of alluvial gold mining is dealing with deposits containing sticky clay and varying gold particle sizes, which require specialized equipment and carefully engineered processing systems. This article explores JXSC’s custom-designed 200TPH alluvial gold processing plant in Ghana, showcasing how modern engineering solutions are addressing these complex mining challenges while maximizing gold recovery rates.
Ghana 200TPH Clay Alluvial Gold Process Plant
Project Overview
The Ghanaian gold mining project presented several specific challenges that required a tailored processing solution:
- Alluvial gold deposits are heavily laden with sticky clay
- Raw materials containing large stones (150-250mm)
- Gold particles ranging from fine to coarse (0-12mm)
- Required processing capacity of 200 tons per hour
These conditions necessitated a comprehensive approach to material handling, clay removal, precise particle separation, and efficient gold recovery. JXSC’s engineering team designed a complete processing system that addresses each of these challenges while maintaining the high throughput demanded by the operation.
Project Design: Process Flow and Equipment
200TPH Clay Alluvial Gold Process Flowchart
The above flowchart was designed based on the gold mine details.
The Processing Workflow
The JXSC gold processing plant follows a systematic workflow designed to handle raw materials and maximize gold recovery efficiently. This setup is a 200tph complete alluvial gold washing plant. The raw materials are 0-250mm ores with much sticky clay, and the alluvial gold size is 0-12mm. It is configured with a hopper, vibrating feeder, trommel scrubber, high-frequency vibration screen, belt conveyor, and sluice box.
1. The truck unloads the ore into the hopper, then the ore enters the vibrating feeder from the lower part of the hopper; the ore larger than 50mm will be separated by the vibrating feeder grizzly bar and transferred by a conveyor to a stockpile.
2. The vibrating feeder feeds the ores less than 50mm ores evenly to the trommel scrubber to wash. They are connected by a chute.
3. The less than 50mm washed materials from the trommel scrubber will be sent to the first high-frequency vibration screen with a 6mm mesh.
4. The material 0- 6mm will pass through the mesh and flow to the 4 sets of sluice boxes. And the material 6- 50mm will flow through the height difference to the next vibrating screen.
5. The material 6- 12mm will pass through the mesh and flow to the fifth sluice box. The ore with a thickness of more than 12mm will be transferred by a conveyor to another stockpile.
6. The tails of the 5 sets of sluice boxes will flow to another 3 sets of sluice boxes for further recovery.
Note: Through this setup, you can get most of the gold particles. You can get other sizes of gold nuggets by changing the mesh sizes. The capacity can be from 5 to 300tons per hour per set.
Key Equipment Components
Vibration Feeder with Grizzly Bars: Controls feed rate and removes oversized material (+75mm), protecting downstream equipment from damage.
Trommel Scrubber: The heart of the clay removal system, featuring either:
- Rubber lining (easier installation, 1-2 year lifespan)
- Manganese steel lining (more economical, 3-6 month lifespan)
The continuous rotary motion with water effectively breaks down sticky clay through impact and attrition.
High-Frequency Vibration Screens: Two sets of screens precisely separate material into 0-6mm and 6-12mm fractions, ensuring optimal gold recovery in the downstream concentration process.
Gold Sluice Boxes: Multiple sluice boxes strategically arranged to capture gold particles from different size fractions, with additional units to recover gold from tailings streams.
Belt Conveyors: Transport oversized waste material away from the processing circuit to dedicated stockpiles.
Common Questions and Answers
1. How to remove the sticky clay in the raw materials?
Answer: The trommel scrubber is used for washing the sticky clay. When it works, it will continue to rotate with water, and the sticky clay will hit and spread in the water.
There are two types of lining of the trommel scrubber:
Rubber lining: easy to change and install, can be used for 1-2years.
Manganese steel: not convenient to change and install, but much cheaper than the rubber lining, and can be used for 3-6 months.
2. How to remove the big stones?
Answer: The feeding size of the trommel scrubber is 0-75mm, there have 150-250mm big stones in the raw material, so we add the vibration feeder with grizzly bar before the trommel scrubber, the sieve of the grizzly bar will be made of 75mm, 0-75mm will to the trommel scrubber, +75mm will to the waste pile.
3. How to get the gold?
Answer: The gold size range is 0-12mm. We add two sets of high-frequency vibration screens after the trommel scrubber, one set for separating the size 0-6mm materials, other set for separating the size 6-12mm materials.
The 0-6mm and 6-12mm will go to the gold sluice box to get the gold concentrate.
Two sets of sluice boxes for each vibration screen, and an additional sluice box for recovering the tailings of the sluice box after the vibration screen.
4. How much water will be needed for the machines?
Answer: The water consumption for the raw materials is 3:1, which means 3m³ of water will be needed for 1 ton of raw materials. Enough water will make sure to clean the sticky clay.
5. How to choose a suitable generator for the machines?
Answer: Add the total power of the machines, then multiply by 1.35; that’s the actual generator that will be needed.
Conclusion
The JXSC 200TPH alluvial gold processing plant in Ghana demonstrates how modern mining engineering can effectively address the challenges of processing clay-rich alluvial gold deposits. Through careful equipment selection, strategic process design, and attention to operational details, the plant successfully handles difficult materials while achieving high gold recovery rates at substantial throughput volumes.
The system’s modular design also allows for customization based on specific deposit characteristics. By changing screen mesh sizes, operators can target different gold particle size ranges. Additionally, the capacity can be scaled from as little as 5TPH to as much as 300TPH per processing line, making similar designs applicable to operations of various scales.
For mining operations facing similar challenges with alluvial gold deposits, this Ghanaian case study provides valuable insights into effective processing strategies and equipment configurations that maximize recovery while efficiently managing difficult material characteristics.