Environmental desulfurization of mine wastes using various mineral processing techniques: Recent advances and opportunities. (1st December 2021)

• Record Type: Journal Article
• Authors: Ait-Khouia, Yassine; Benzaazoua, Mostafa; Demers, Isabelle
• Is Part Of: Minerals engineering. Volume 174(2021)
• Publication Date: 2021-12-01
• Subjects: Mine wastes -- Sulfides -- Sulfosalts -- Contaminated mine drainage -- Environmental desulfurization -- Flotation; Mines and mineral resources -- Periodicals; Ressources minérales -- Périodiques; Mines and mineral resources; Periodicals; Electronic journals; 622
• DOI: 10.1016/j.mineng.2021.107225
• Languages: English
• ISSNs: 0892-6875

Abstract

Graphical abstract: Highlights: Physical separation techniques could be used to desulfurize mine wastes. Physical separation techniques can achieve the same performance as flotation. Physical separation techniques are efficient, less expensive, and ecofriendly. Suitable technique depends on mineralogy, texture and particle size of waste. Combinations of techniques including flotation improve desulfurization efficiency. Abstract: Management of mine wastes (e.g., waste rock and tailings) is becoming an increasing global environmental concern for mining industries around the world. With environmental regulations becoming more restrictive, there is a continuously growing need to develop efficient and clean integrated techniques to sustainably manage mine wastes. Mines wastes often contain acid-forming minerals, such as sulfides and sulfosalts that are responsible for generating contamination. Environmental desulfurization using non-selective flotation has recently been implemented as an integrated management approach for mine tailings. Furthermore, physical separation techniques, commonly used in mineral processing and offering a remarkable potential for sulfur and valuable minerals enrichment, are rarely used to manage mine wastes. The separation methods for sulfides and sulfosalts, which are based on the physical properties of the minerals, can achieve the same performance as flotation. These physical properties are mainly related to: i) the particle size distribution, ii) the difference in density between the targeted minerals (i.e., sulfides and sulfosalts) and those of the gangue minerals, iii) the magnetic properties, iv) the electrical attributes, and v) the response to specific sensing. Based on the discrepancy between mineral properties, various methods are proposed, including sieving/screening, hydrodynamic classification, gravity concentration, dense medium separation, magnetic and electrical separation, and sensor-based sorting. These techniques could be considered to be more efficient, less expensive, and more respectful of the environment than flotation. This critical review aims to evaluate the suitability of these physical separation techniques, other than the widely used flotation, to mine waste environmental desulfurization. The paper includes a brief description of these techniques, a discussion of their advantages, and their limitations for the removal of the most common sulfides and sulfosalts (mainly responsible for contaminated mine drainage). Indeed, the application of one or more of these mineral processing techniques requires specific conditions, which depend on the size-by-size mineralogical characterization of each mine waste. The specific requirements for the application of each technique are explored.