Optimized design and fabrication of a wind-sifter separator for enhanced dry beneficiation of high-ash coal

Abstract

• The current design achieves superior recoveries and outperforms the prototype. • Lower air velocity decreases ash content in coal but reduces yield too. • Shape’s effect is prominent in coarse fraction and diminishes with size reduction. • Size & density majorly affect particle separation with less influence at smaller sizes. The high mineral content in coal exacerbates environmental pollution, therefore, reducing the ash content is essential. This study reports the effectiveness of an optimized wind-sifting separator in upgrading high ash coal based on size and density through computer simulations employing the Lagrangian particle tracking method. This new separator was designed using Autodesk-Inventor and assessed with and without particle collecting bins via simulation using STAR-CCM+ TM software. Three particle sizes (−6.7 + 3.35 mm, −3.35 + 1 mm, −1 + 0.2 mm) were tested experimentally at different airstream velocities to ascertain optimal velocities (cut point of 1.6 g/cm 3 ) for each size fraction. The investigation into the impact of particle shape on separation efficiency revealed that shape affects the separation of larger particles significantly, with this effect diminishing as particle size decreases. The laboratory-scale separator effectively reduced the ash content in the feed coal from 37.38 % to 24.11 %. The findings imply that the optimized separator holds promise for upgrading the quality of coal and various minerals within the mineral processing sector, thereby contributing to a cleaner and more sustainable energy future.