What Factors Affect The Selective Grinding?

In the grinding stage, selective grinding can achieve the purposes of separating different minerals from each other, preventing the over-grinding of valuable minerals to be recovered, and reducing the over-crushing of gangue minerals. In the grinding process, there are many factors that affect the selective grinding effect, such as ore properties, mill type, operating conditions, etc. The factors affecting selective grinding will be discussed below from these three aspects.

Influence of Ore Properties on Selective Grinding

The cohesive force of the binding surface between different substances is different, resulting in different mechanical properties of different minerals. Therefore, any ore composed of two or more minerals is preferentially fractured at the weaker cohesive force during the grinding process.

The grinding behavior between different minerals is mainly reflected in the shielding effect of hard minerals on soft minerals. Soft minerals can catalyze and promote hard minerals, and the greater the hardness difference, the stronger the catalytic and shielding effects. At the same time, the selective grinding effect is enhanced with the coarsening of the feed particle size and the increase of the non-uniformity of the ore particle strength. As the particle size of the ore decreases, the inhomogeneity of the ore particle strength becomes smaller and weaker.

Effect of Mill Type on Selective Grinding

The common grinding equipment includes a ball mill, rod mill, autogenous mill, semi-autogenous mill, vibration mill, stirring mill, etc. Due to different working principles, the selective grinding effect on ore is also different. In addition, the ratio of mill diameter to length and the type of mill lining also have different effects on selective grinding.

Influence of Operating Conditions on Selective Grinding

In addition to the above factors, the operating conditions of the mill will also affect the selective grinding, including factors such as grinding concentration, grinding medium, medium filling rate, and mill time.