The mechanisms of improved chalcopyrite leaching due to mechanical activation

- An efficient chalcopyrite leaching method involving mechanical activation was derived.
- Solid state reaction occurred during chalcopyrite grinding with Fe2(SO4)3·xH2O to produce dissoluble CuSO4.
- Approximately 98% copper was extracted within 1.5 h.
- No acid was required for the leaching of ground chalcopyrite.

Chalcopyrite leaching has attracted much attention in both research work and industrial implementation due to its low cost. However, the slow Cu leaching rate during chalcopyrite dissolution process limits its wide application. This paper investigated the influence of mechanical activation on chalcopyrite leaching. The results showed that co-grinding of chalcopyrite and oxidants (i.e. Fe2(SO4)3·xH2O) stimulated solid-state reactions to form dissolvable copper sulfate, thereby increasing Cu extraction rate significantly. The reactions gradually proceeded with the increase of grinding time and speed, as well as the amount of oxidant. After activation, more than 98% of chalcopyrite was extracted in pH 1.0 sulfuric acid maintained at 348 K for 1.5 h, significantly greater than that without activation, indicating a promising strategy for high efficient chalcopyrite leaching.