When several different materials undergo the same crushing process in the same crushing equipment, the crushing situation is more complex than that of a single material due to the mutual influence of various materials.
At present, there are still divergent views on whether and how various materials affect the mixing and crushing process of multiple materials.
One view is that when materials are mixed and crushed, there is no mutual influence. It is believed that whether crushed separately or mixed, the particle size distribution of each component in the mixed material essentially follows the same Schumann particle size distribution function.
Another view is that various materials have mutual influence, but there are two completely different views on the results of the influence.
Some people believe that there is a common mutual influence in the quality inspection of materials in mixed powders. Among them, hard materials have a "shielding" effect on soft materials, thus protecting them and slowing down their crushing speed; Conversely, soft materials have a "catalytic" effect on hard materials, thereby accelerating their crushing speed. Due to these two reverse effects, the software and hardness are different The grindability of materials tends to be consistent The catalytic effect of soft materials on hard materials. The crushing effect on hard materials at the contact point will be stronger than that on surrounding soft materials. In other words, the mixing of soft materials accelerates the crushing speed of hard materials. This effect is called the catalytic effect of soft materials on hard materials. As a result, the coarse particle yield of hard materials is lower than that of their individual crushing, while the fine particle yield is higher than that of their individual crushing
In fact, during the process of crushing or grinding, the materials between the crushing media are often multi particle layers, and the force of the media on the materials can be transmitted between particles without directly contacting them to cause crushing. It is common for fragile materials to be finer when mixed and crushed than when crushed separately, and for difficult to crush materials to be coarser when mixed and crushed than when crushed separately. We refer to the phenomenon of selective crushing where a certain material is crushed before others when multiple materials are crushed together.
There are at least two reasons why this phenomenon occurs.
1. The particle layer is subjected to the force of the crushing medium, even if it is not enough to shatter the high-strength material particles, most of it will be transmitted to the lower strength particles adjacent to it in the direction of the force, which is enough to cause crushing. In this sense, hard particles have a catalytic effect on soft particles.
2. When two different particles interact and move relative to each other, the harder one will produce surface shear or grinding effects on the harder one. Soft particles will be ground by hard particles on the contact surface to form several fine particles. At this point, hard particles act as grinding media for soft particles.
