Heap Leaching vs. Tank Leaching for Gold Extraction

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In the gold mining industry, choosing the right extraction method can significantly impact both operational efficiency and project economics. Two of the most widely used hydrometallurgical techniques for gold extraction are heap leaching and tank leaching (also known as agitation leaching). Each method has its advantages and limitations depending on ore type, project scale, and budget.

This article compares heap leaching vs. tank leaching in terms of process, cost, recovery rates, and suitability, helping mining companies, investors, and engineers make informed decisions.

Heap leaching is a low-cost, scalable method used to extract gold from low-grade ores. It involves stacking crushed ore on a prepared pad and applying a leaching solution—usually a cyanide solution—that percolates through the heap and dissolves the gold. The solution is collected at the bottom, and gold is recovered from the liquid.

Key Features:

• Low capital cost

• Ideal for large-scale, low-grade deposits

• Slow processing time (months to years)

• Simple design and low energy consumption

  

Tank leaching (agitated leaching) is a more controlled process where finely ground ore is mixed with leaching solution in large tanks equipped with mechanical agitation. This method is commonly used for high-grade ores and offers faster recovery times.

Key Features:

• Higher gold recovery rates (typically 90%+ for suitable ores)

• Faster leaching process (hours to days)

• Higher capital and operational costs

• Requires more infrastructure and energy

  

The choice between heap leaching and tank leaching depends on several factors:

• Ore Characteristics: Oxide ores with low-grade gold are better suited to heap leaching. Refractory or sulfide ores may require tank leaching or pre-treatment.

• Project Budget: Heap leaching offers a lower upfront investment, making it attractive for junior mining companies or early-stage projects.

• Timeline: If rapid gold recovery is a priority, tank leaching may be the better choice.

• Environmental Considerations: Both methods require careful cyanide management, but tank leaching offers greater process control.

Contact us today to discuss your gold extraction needs and let our team recommend the right leaching solution for your operation.