Modular misplacement investigation journey at Bank 2 coal washing plant

¹ Metallurgical Engineer, Metallurgy Department, Goedehoop Colliery, South Africa
² Plant Manager, Metallurgy Department, Goedehoop Colliery, South Africa
³ Metallurgical Manager, Metallurgy Department, Goedehoop Colliery, South Africa,
⁴ Head of Coal Processing and Business Improvement, Thungela Resources, Rosebank, South Africa

Abstract

Goedehoop North Plant experienced misplacement challenges that often came in the form of struggling to balance production and classification for ensuring the correct particle size distribution was being fed to the correct circuits. The philosophy that a trolley would often be used to push material to a smaller aperture banana screen often fed fine coal material to the wemco section leading to high misplacement values. The first step taken was to produce a feed distribution that would ensure the wemco bins were fed evenly by maintaining similar feed bin levels using a flopper. An improvement was observed on misplacement but showed further optimisation was needed. This was then further followed by changing the panel apertures on the wemco two banana screens from 16mm to 20mm aperture sizing for permanently eliminating fines fed to the wemco section and upgrading the DMS circuit feed from 550 tons per hour to 650 tons per hour by deconstraining a key conveyor belt. With the changes made, the used screen panels were set to a coarser aperture and kept the same for both screens which prevented the misplacement of fine coal into the WEMCO circuit and has significantly reduced the overall plant product coal misplaced to discard. This strategy used has seen the Plant running optimally by meeting the required rates and classifying feed to plant efficiently.