Column leaching of low-grade sulfide ore from Zijinshan copper mine

• Chemical copper leaching effectively proceeded at 60 °C, 37.1 g Fe(III) L− 1 and pH 1.0.
• At 30 °C, microorganisms stimulated copper and pyrite dissolution.
• Low amount of acid-consuming gangue maintained low pH and high dissolved Fe(III).
• Aeration and inoculation were not needed in Zijinshan copper heap bioleaching.
• Ferric ion precipitated as jarosite in columns without recirculation.

Copper and iron dissolution of Zijinshan low-grade copper sulfide ores was investigated in ore-packed columns. At 60 °C and pH 1.0, 37.1 g Fe(III) L− 1 permitted effective copper dissolution and inhibited the activity of iron-oxidizing microorganisms. At 30 °C, microorganisms stimulated Fe(II) and pyrite oxidation, resulting in 85 and 54% of copper and pyrite extraction yields, respectively. Bacteria belonging to the genera Acidithiobacillus and Leptospirillum were dominant as observed by real-time PCR assay. Aeration and inoculation of columns were not necessary. Solutions had a higher pH of 1.7 in the columns operated without recirculation. Under these conditions, copper extraction was not affected and Fe(III) precipitated as jarosite, indicating a novel method for iron control in Zijinshan copper mine.