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.