Grinding mills are among the largest pieces of equipment in a mineral processing plant. To ensure good grinding performance and high operating rates, strict adherence to operating procedures is essential when starting and stopping the grinding mill unit (including the grinding mill, classifier, lubrication system, and feeder) to prevent major equipment accidents. Generally, the following principles should be followed:
(1) Before starting the equipment, a comprehensive and detailed inspection of the grinding mill unit should be conducted to eliminate any malfunctions that may affect startup.
(2) When starting the equipment, start each piece of equipment sequentially from back to front (bottom to top) according to the material flow direction: oil pump – classifier – grinding mill – belt conveyor – feeder. Simultaneous startup of multiple pieces of equipment is strictly prohibited. When planning to shut down, stop the equipment sequentially from front to back (top to bottom): feeder – belt conveyor – grinding mill – classifier – oil pump. (3) Each piece of equipment should be started at certain intervals. Feeding should only begin after all equipment is running normally and stably. For example, start the grinding mill only after the oil pump is working normally, and wait 2-3 minutes after the grinding mill has been running before starting ore feeding.
(4) If the grinding mill has been shut down for more than 4 hours, it should generally be rotated 2-3 times before restarting to loosen any adhered sludge and media.
(5) Normal shutdown (planned shutdown) should be carried out under no-load conditions, and the material inside the equipment should be emptied as much as possible (e.g., the grinding mill should be stopped 15-20 minutes after ore feeding has ceased) to create conditions for the next startup.
(6) The grinding mill should not run for too long without feeding, usually less than 20 minutes, to reduce steel ball consumption and liner damage.