Collaborative optimization of dense medium separation system under the condition of online switching between raw coal desliming and non-desliming feed

In response to issues such as suboptimal separation efficiency and insufficient equipment capacity in the dense medium separation system, arising from the implementation of the online switching process between raw coal desliming and non-desliming feed, the Xin′an Coal Industry Co. Ltd. Coal Preparation Plant upgraded the original traditional-structure pressure-free feeding three-product dense medium cyclone to a dual-cone structure. Additionally, the plant replaced the accompanying reject medium drainage screen and improved the transportation capacity of the tubular belt conveyor for reject, achieving collaborative optimization of the system. Following the optimization, the dense medium separation performance improved significantly: the probable deviation of the primary cyclone decreased to 0.03 g/cm³, and that of the secondary cyclone reached 0.045 g/cm³; the coal loss in middlings dropped from 20% to 1.32%, and the coal loss in gangue approached zero. The raw coal processing capacity increased by 50 t/h, and the clean coal yield rose by 1.39 percentage points. Meanwhile, media consumption per ton of coal was reduced by 0.15 kg, and power consumption per ton decreased by 0.56 kW·h, resulting in an estimated annual economic benefit of approximately 6.8554 million yuan. This optimization practice can provide valuable insights for coal preparation plants with similar production conditions in optimizing their separation processes.