E BAAWUAH1, C KELSEY2, J ADDAI-MENSAH3 AND W SKINNER4
Steel has been a major contributor to the recent global industrialisation due to its unique combination of strength, formability, versatility, recyclability and low cost. The primary raw material for steel making is metallic iron extracted from iron ore concentrates comprising magnetite, hematite and goethite minerals. As high-grade iron ores decline, the iron ore industry is shifting to mining and processing of low-grade and complex ores. As a result, large amounts of energy are expended on crushing and grinding both the mineral of interest and associated gangue minerals.
Low-grade magnetite mineralisation is generally fine-grained and requires fine to ultrafine grinding (P80 <45 μm) to achieve sufficient liberation from the predominantly silica/silicate gangue matrix for effective beneficiation to make saleable Fe grades. Because of this, there is the need for frugal energy use in mineral processing and this motivated the development of a novel super-fine crusher (SFC) that reduces coarse feed to fine and ultra-fine products with minimal recycle loads and lower energy input.
In this study, the effect of selected operating parameters of the SFC on product particle size distributions, particle reduction ratio and energy consumption has been investigated and discussed. It is shown that the novel SFC provides a significant potential for step changes in mineral comminution flowsheets with associated reduction in energy consumption and environmental footprint.
Keywords: Comminution, superfine crusher, particle size distribution, comminution energy