ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Flotation separation of pyrite and chalcopyrite with potassium permanganate as a depressant

Qinbo Cao, Haiyu Zhang, Yan Yan, Yanjun Li, and Dianwen Liu

Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming, People’s Republic of China

E-mail: qinbocao@kust.edu.cn

Received: 31 July 2023  Accepted: 6 November 2023

Abstract:

The separation of chalcopyrite and pyite is not fully solved, and thus more efficient depressants are still needed in industry. This paper used potassium permanganate (KMnO₄) as a pyrite depressant to separate pyrite from chalcopyrite. Flotation and contact angle results indicated that pyrite could be depressed by KMnO₄ at pH 7, while KMnO₄-treated chalcopyrite could be floated by sodium ethylxanthate. For the pyrite-chalcopyrite mixture, the recovery of chalcopyrite was nearly 95% and that of pyrite was less than 15% when minerals were reacted with 4 × 10⁻⁴ KMnO₄ for 3 min. The KMnO₄-treatment raised the zeta potential of pyrite at pH 7, which may generate oxidized species on the pyrite surface. The oxidation products on the pyrite surface were FeO, FeOOH, and Fe₂(SO₄)₃ as determined by XPS analyses. These oxidation products were well coated on the pyrite surface, which dramatically lowers the hydrophobicity of pyrite. In contrast, in the case of chalcopyrite, KMnO₄ treatment did not generate new oxidation components on its surface, causing the chalcopyrite surface to remain hydrophobic and allowing the flotation of chalcopyrite by air bubbles. Thus, pyrite could be efficiently separated from chalcopyrite using KMnO₄ as a depressant.

Keywords: Potassium permanganate; Depressant; Chalcopyrite; Pyrite

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-03203-6

Chemical Papers 78 (3) 1761–1773 (2024)