“Bloating” doesn’t happen suddenly; it’s a process of occurrence, development, and deterioration, accompanied by various abnormal phenomena. This requires workers to be responsible, promptly identify and adjust accordingly, eliminating “bloating” in its mildest stage. The following phenomena can be used to determine if “bloating” is occurring:

(1) Observe the current. During normal operation, the ammeter pointer of the main motor of the grinding mill always fluctuates within a small range, indicating minimal current change. Once “bloating” is about to occur, the amount of material inside the grinding mill increases, the effective space is occupied by a large amount of material, resulting in a smaller range of media movement, reduced useful work of the lifting media, and a higher center of gravity of the grinding mill load (media, ore), i.e., a smaller distance from the center of the grinding mill. This reduces the resistance torque generated by eccentricity, decreases the power required to overcome the resistance torque, and lowers the total energy consumption of the grinding mill, thus reducing the current reading reflected by the ammeter. The more severe the “bloating,” the greater the current drop, reaching its lowest point when the grinding mill is “bloated.” Therefore, once the operator notices a gradual decrease in current, they should adjust it promptly to prevent accidents.

(2) Listen to the sound. The sound emitted by the grinding mill during operation mainly originates from the transmission mechanism itself and the mutual impact between the medium, ore, and liner inside the mill. The intensity of the impact sound inside the mill varies depending on the amount of material in the mill. When the mill becomes unbalanced and “bloated,” it is filled with a high-concentration slurry. The impact of the medium on the ore and liner is weakened by the viscous slurry, and the sound gradually becomes muffled. In severe “bloating,” the sound inside the mill almost disappears, and only a buzzing sound can be heard from other directions. Therefore, the change in the intensity of the sound during mill operation can indicate whether the mill is “bloated.”

(3) Measure the concentration and observe the discharge. The discharge concentration and discharge volume of a normally operating grinding mill should be basically stable. However, when it becomes “bloated,” the concentration begins to rise, the discharge volume increases, the particle size becomes coarser, and a “front discharge and back pull” phenomenon occurs. In severe cases, due to excessive concentration and poor fluidity, the ore cannot be discharged, and when it is completely “bloated,” ore discharge stops. Therefore, “bloating” can also be detected by observing changes in the concentration, particle size, and discharge volume of the ore discharged from the grinding mill.