Leaching is a key metallurgical technique in mining that uses chemical solutions to dissolve valuable metals from ore, leaving impurities behind.
This process enables efficient metal recovery from low-grade or complex ores unsuitable for conventional processing.
The ore is first crushed or ground to maximize surface area, then exposed to a leaching agent such as cyanide for gold or sulfuric acid for copper which reacts with the target metal to form a metal-rich (pregnant) solution.
The dissolved metals are subsequently recovered through methods like solvent extraction or electrowinning.
Heap leaching involves stacking crushed ore on lined pads and irrigating it with a leaching solution that percolates through the heap, dissolving metals for collection at the base.
This cost-effective method is ideal for low-grade ores of gold, copper, and uranium that are uneconomical to process conventionally.
The process relies on chemical reactions, often aided by oxygen and iron, to enhance metal dissolution, achieving high recovery rates typically 60–80% for gold and over 85% for copper.
What specific lixiviant (like cyanide or sulfuric acid) do you believe presents the biggest challenge in terms of cost, safety, or environmental management? Share your insights!
