Discussion on the problem of grinding powder limit of Raymond mill
Due to the limitations of modern smashing methods, it has not been possible to obtain a product that achieves the absolute limit of particle size, and it is difficult to obtain a 10-fold or even 100-fold particle size, such as 1 to 0.1 μm. Some people have extended the grinding time to more than 100 hours, and the fineness of the product obtained is not much reduced. Even with the prolongation of grinding time, the mineral grain size of some minerals is not thinner but thicker. This phenomenon is very common in dry pulverization of non-metallic minerals. Therefore, there is a crushing actual limit particle size here. According to some scholars' research, the reason for the smashing limit granularity is:
(1) Any of the existing equipments, because of its characteristic characteristics, its crushing (grinding) ratio is certain, so it is difficult to exceed the actual limit of crushing;
(2) The energy and energy utilization rate of any existing pulverizing equipment is constant, and the pulverizing effect depends on the size and energy utilization of the pulverizing energy of the equipment. Extending the pulverization time, the cumulative energy is accumulated, and the amount of accumulated energy is not the decisive factor of smashing;
(3) As the particle size decreases, the surface energy increases, resulting in an increase in the polymerization force (cohesion or adhesion) of the particles, thereby forming a particle size reduction and a dynamic balance particle size of the polymerization;
(4) As the particle size decreases, the misalignment of the crystal surface and the apparent dislocation of the crystal structure during the pulverization process cause mechanochemical changes. If an amorphous film is formed on the surface of the quartz, the calcite becomes nepheline or the like;
(5) As the particle size decreases, the fracture resistance of the particles increases, and the pulverization energy required for primary pulverization increases remarkably, resulting in dispersion of pulverization energy.
The above is the discussion and analysis of the grinding limit of the mill by SBM Heavy Industry (Raymond Mill, Raymond Machine).