Distinguishing Gangue and Liberated Gold Particles
In the context of primary gold recovery, gangue refers to the non-valuable minerals and rocks that are mixed with the ore. It does not contain significant amounts of gold.
Liberated gold particles are the gold particles that have been separated from the gangue and are free to be recovered.
Identifying Major Losses of Gold
Village miners in East Africa face several challenges that lead to significant losses of gold during the recovery process.
1. Wooden Sluices & Jute Matting
Many village miners use wooden sluices with jute matting, which are highly inefficient.
- Jute is porous, allowing gold to wash straight through.
- Wooden sluices lack proper sides, causing water and fine gold to escape.
- Gaps between planks create opportunities for gold to drop out.
- Concentrate accumulates beneath the matting but is often forgotten.
2. Mercury Use
The use of mercury poses serious environmental and health risks.
- Due to surface tension, mercury fails to capture smallest (or even large) gold particles.
- At least 20% of gold is lost when mercury is used.
- We strictly prohibit the use of mercury.
3. Insufficient Concentration
Village miners often concentrate gold only once.
This results in incomplete separation of gold from gangue, leading to additional gold losses in subsequent processing stages.
4. Inadequate Machinery
Lack of proper crushing and grinding machinery.
This leads to inefficient liberation of gold particles, leaving a significant portion of gold embedded in gravel and sand.
Procedure for Improved Gold Recovery
The following is a staged, cost-effective approach designed to minimize costs and risks while maximizing returns.
Step 1: Recovering Liberated Gold Particles
Goal: Immediate cash recovery from free-milling gold.
- Use specialized SYOGM Fine Gold Recovery Sluices (scientifically designed to capture particles down to 5 microns).
- Process tailings (e.g., 10 or 100 tonnes) and record weights recovered.
- Aim to capture 98% to 99.9% of free gold particles.
- Evaluate expenses vs. value to decide if further processing (re-milling or leaching) is profitable.
Step 2: Re-Milling and Gold Grade Verification
Goal: Release trapped gold and verify grade before chemical processing.
- Re-mill the tailings to break down material and release additional gold particles.
- Analyze and verify the gold grade obtained from re-milling.
- Use the SYOGM Rothensteed Rock Mill (Wheel-Rotated Mesh Screen) to achieve 200 mesh (approx 70 microns).
- Conduct Particle Size Distribution analysis to ensure at least 95% of gold is recovered down to 200 mesh.
- Evaluate profitability before proceeding to leaching.
- Strategy: Avoid leaching whenever technologically feasible, as traditional sluices cannot recover fine gold like our systems.
Step 3: Expanding Recovery Methods Based on Results
Goal: Data-driven scaling decisions.
- If Re-Milling is profitable: Proceed to remill all tailings and scale up processing capacities.
- If Re-Milling is NOT profitable: Focus solely on Step 1 (Direct Liberation) and skip re-milling.
This decision must be based on the Prospecting Check Report to ensure engineering-like decision making.
Step 4: Leaching and Final Gold Recovery
Goal: Environmentally friendly final recovery.
- Analyze particle sizes after re-milling.
- Use non-invasive, environmentally friendly leaching agents (avoiding cyanide).
- Prefer CIL (Carbon-in-Leach) over heap leaching for faster, higher recovery rates.
- Analyze results and devise additional methods to recover remaining gold (e.g., inexpensive milling improvements).
A Staged, Cost-Effective Approach
The procedure follows a logical sequence: Recovery → Re-Milling → Verification → Leaching (Last Resort). This progression minimizes costs and risks while maximizing returns, aligning with best practices in mineral processing.
Solar-Powered Water Supply
Environmental Responsibility
Whenever possible, water should be supplied using solar-powered water pumps.
- Use DC pumps powered by batteries charged through solar panels.
- Reduces operational costs and carbon footprint.
- Provides a sustainable solution for remote artisanal mining sites.
"Integrating solar power ensures that gold recovery is not only profitable but also sustainable for future generations."
Solar Energy Integration
Efficient, Clean, Renewable
Tailings Processing Services
By implementing the above procedure, significant improvements can be achieved in gold recovery from artisanal tailings in East Africa.
What We Offer
- Processing: Efficient tailings processing using SYOGM technology.
- Training: Training staff members on mercury-free methods and safe operations.
- Equipment: Provision of specialized equipment including Rock Mills and Fine Gold Sluices.
- Consultancy: Engineering-level analysis and decision-making support.
Potential Returns
The potential profits for tailings owners are immense. By recovering gold that was previously wasted, owners can generate significant revenue from existing tailings piles without the environmental impact of new excavation.
With regards,