Abstract:
To address the problems of excessive medium consumption and high production costs at Changzhi Jingfang Coal Preparation Plant, this study aims to reduce medium consumption, control coal preparation costs, and improve economic benefits by investigating effective medium consumption reduction measures. In terms of process optimization, the coal washing flowsheet was optimized by adding magnetic separators for clean coal and middlings to increase the magnetic separation capacity, while the underflow of the first-stage thickener was subjected to further magnetic separation to maximize medium recovery. In terms of equipment modification, several targeted retrofitting measures were implemented: pre-drainage devices were installed at the collection boxes of clean coal and middlings to promptly return the medium to the dense medium system and enhance pre-drainage capacity; a zigzag impurity remover was added at the head of the raw coal feeding belt conveyor to improve screening efficiency; filtration devices were installed in the circulating water pipeline, and booster pumps were added to the spray headers of the drainage screens to prevent nozzle clogging and increase spray pressure; online monitoring devices were installed at the magnetic separator feed to ensure stable feed conditions and improve magnetic separation efficiency. In terms of management, strict medium quality control was enforced by establishing clear quality standards and improving medium acceptance procedures. After the retrofitting, the medium consumption of the plant was reduced from 1.50 kg/t to 0.48 kg/t, saving approximately 1.08 million yuan annually in medium costs, significantly reducing coal preparation costs and improving the plant’s economic performance.