| Download | - View final version: An environmentally friendly method for efficient atmospheric oxidation of pyrrhotite in arsenopyrite/pyrite calcine (PDF, 2.6 MiB)
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| DOI | Resolve DOI: https://doi.org/10.1016/j.ceja.2021.100122 |
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| Author | Search for: Li, Lin1ORCID identifier: https://orcid.org/0000-0002-9109-6233; Search for: Wang, Jingxiu; Search for: Wu, Chengqian; Search for: Ghahreman, Ahmad |
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| Affiliation | - National Research Council of Canada. Energy, Mining and Environment
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| Format | Text, Article |
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| Subject | calcine; oxidation; pyrrhotite; thermal phase transformation; sulfur balance; pyrolysis |
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| Abstract | Pyrite and arsenopyrite are the most common hosts for invisible gold, but pyrite and arsenic are refractory during conventional sulfide oxidation, which significantly challenges subsequent gold extraction. One option is high-temperature pretreatment of arsenical materials to sequester > 90% of the arsenic as a gas, then convert it to a stable form. This process produces a calcine similar in composition to pyrrhotite (Fe₁₋ₓS) but with higher porosity. In this study, the calcine product is oxidized with an efficient, cost-effective atmospheric process using acidic and near-neutral solutions. A sulfur mass balance analysis method based on iron sulfide thermal transformation in nitrogen atmosphere was developed to quantify the oxidation efficiency of pyrrhotite leaching. The optimization confirmed that > 90% of the calcine was oxidized by Fe³⁺ (5 and 10 g/L) and O₂ (0.5 L/min) at pH 1 after 48 h and at 95 °C even without ultrafine grinding. Elemental sulfur was the main oxidation product when the oxidation pH was 1,2. This study provides the foundation for the development of a low-cost and environmentally friendly process option for pretreatment of arsenical sulfide refractory gold materials. |
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| Publication date | 2021-05-23 |
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| Publisher | Elsevier |
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| Language | English |
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| Peer reviewed | Yes |
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| Identifier | S2666821121000387 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | 09b3ea74-3584-4d23-a37e-288f2b16f471 |
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| Record created | 2022-09-06 |
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| Record modified | 2025-03-26 |
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