In the actual operation of the
nano sand mill, the crushing of material particles mainly depends on the collision, extrusion and shearing between the grinding beads moving at high speed to achieve the particle size of the material particles smaller and the specific surface area increased. In the process of particle size refinement, particles will reunite under the influence of van der Waals force and double electric layer electrostatic action. That is, after grinding and sticking together! This will greatly reduce the production quality, so we need to choose dispersant at this time to solve the problem. , accompanied by a series of qualitative changes in the physical and chemical properties of particles, a "crushing? Reunion "reversible process. When the speed of the positive and negative processes is equal, the dynamic equilibrium in the comminution process is achieved, and the particle size reaches the limit value. At this point, further prolonging the comminution time is useless. Because the mechanical force at this time is not enough to deaggregate the aggregates to further break the particles, it can only be used to maintain the crushing balance, and may cause more small particles of the aggregates, so the so-called "reverse grinding", "back roughing" phenomenon will appear. To a certain extent, the proper selection of dispersant is the only effective way to solve the phenomenon of "reverse grinding" and "back-roughing". Dispersants can affect van der Waals forces between particles, electrostatic forces of double electric layers, spatial repulsive forces of solvated film and adsorbed layer.
