Pushing the frontiers of ultrafine crushing and the impact on comminution energy and mineral liberation

• Current mining projects are targeting low-grade abrasive ores which require fine and ultrafine comminution and beneficiation. • Cost associated with comminution can be a major bottleneck on the economic viability of mineral projects. • A laboratory-scale superfine crusher is investigated, and its performance is compared with a Bond ball mill. • The crusher and ball mill performance are discussed in terms of energy and mineral liberation of their discharge materials. • A proposed dry comminution flowsheet has the potential to reduce comminution energy demand and improve efficiency. The current mining climate has seen a steady increase in research and development of less energy-intensive ore mining and processing pathways, particularly for low-grade abrasive ores. Invariably, mine operators are continually seeking innovative capital and operating cost reduction options for energy- and capital-intensive unit operations such as comminution to stay competitive. In this study, the performance of a novel laboratory-scale superfine crusher and a ball mill, in terms of comminution energy requirement and mineral liberation characteristics, is investigated for magnetite ore beneficiation. The impact of particle size reduction using the superfine crusher and ball mill on specific energy input, particle size distribution, mineral liberation, and the response of their respective discharge products to magnetic separation was also probed. The study demonstrated the ability of the novel superfine crushing technology to produce ultrafine particle sizes historically executed by milling and grinding technologies, with a corresponding improved mineral liberation and frugal energy use.