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Efficient recovery of gold and silver from ore requires stable separation, controlled slurry behavior, and effective solid–liquid management. In modern mining operations, polyacrylamide (PAM) is widely used as a key flocculant to improve sedimentation efficiency, enhance metal recovery, and support environmentally responsible processing.
Thanks to its strong polymer bridging ability and adaptability to different ore systems, PAM has become an essential reagent in gold and silver extraction circuits.
Role of Polyacrylamide in the Gold and Silver Extraction Process
1. Ore Crushing and Slurry Preparation
Gold and silver ores are first crushed and ground to fine particles. During this stage, the ore is mixed with water and lime to form a uniform slurry. Proper slurry stability is essential for downstream sedimentation and leaching efficiency.
Polyacrylamide helps maintain uniform particle dispersion and prevents excessive fine solids from remaining suspended in later stages.
2. Thickening and Sedimentation
After grinding, the slurry enters a thickener for solid–liquid separation. Polyacrylamide flocculants are added to promote particle aggregation. Fine mineral particles rapidly form larger flocs, which settle efficiently at the bottom of the thickener.
This step produces clarified overflow water and concentrated underflow slurry, creating ideal conditions for leaching and adsorption.
3. Cyanide Leaching Stage
The thickened slurry flows into leaching tanks where cyanide dissolves gold and silver from the ore. PAM supports consistent slurry flow and prevents solid stratification, ensuring effective contact between cyanide solution and mineral surfaces.
Improved slurry behavior directly enhances leaching efficiency and metal dissolution rates.
4. Carbon Adsorption (CIP / CIL)
Once precious metals are dissolved, activated carbon is introduced to adsorb gold and silver from the solution. Polyacrylamide improves suspension stability, reduces carbon fouling, and promotes uniform mixing inside adsorption tanks.
Stable hydrodynamics increase adsorption efficiency and maximize metal recovery.
5. Tailings Treatment and Water Recovery
After metal recovery, tailings are discharged for final clarification. PAM is applied again to accelerate tailings settling, clarify recycled water, and reduce suspended solids in discharge streams.
This supports water reuse, lowers fresh water demand, and improves tailings pond stability.
Benefits of Using Polyacrylamide in Gold and Silver Mining
Improved Recovery Efficiency
Optimized flocculation and sedimentation can significantly increase gold and silver recovery rates while reducing metal losses in tailings.
Faster Processing Cycles
Enhanced settling and flow behavior reduce residence time in thickeners and tanks, increasing plant throughput.
Lower Operating Costs
Reduced reagent consumption, improved water recycling, and lower sludge handling costs contribute to overall cost efficiency.
Environmental Compliance
Cleaner effluent water and improved tailings management help mining operations meet environmental regulations and sustainability goals.
Polyacrylamide Selection for Mining Applications
Polyacrylamide used in gold and silver extraction is typically selected based on:
Ore mineralogy and particle size distribution
Slurry pH and ionic environment
Process stage (thickening, leaching, tailings)
Desired settling speed and floc strength
Anionic PAM is commonly used in thickening and tailings treatment, while nonionic or customized grades may be applied depending on ore characteristics.
Summary
Polyacrylamide plays a critical role in gold and silver ore extraction by improving flocculation, enhancing sedimentation, stabilizing slurry flow, and supporting efficient water recovery. When properly selected and dosed, PAM helps mining operations increase metal recovery, reduce processing time, and improve environmental performance. Its versatility and cost-effectiveness make it an indispensable reagent in modern precious metal mining systems.
