Use of Mechanochemical Effect in Milling Process

In the grinding process, with the various mechanical forces of the powder particles and the change in the crystal structure, the nature of the physical-chemical and chemical reaction, the chemical effect of the mechanical force can be applied to the synthesis of new materials, the use of grinding aids and chemical modification of the mechanical force.
First, we will talk about the synthesis of new materials. Using the chemical effect of the mechanical force can synthesize the new materials which can not be synthesized under normal circumstances. The new materials synthesized by the chemical effect of the mechanical force are more excellent than the new materials synthesized by the conventional method. The material can be either inorganic material or metallic material. It also may be the organic polymer material. The high-energy material used in ball mill is the application of the mechanochemical effect in the field of materials.
Second, this paragraph will explore the use of the grinding aids. The crushin of the particles means that the break of the chemical bonds and re-combination of the substance. With pulverization and generation of the fracture surface, unsaturated covalent bond and structural unit with charge appear on the surface of the particles so that the particles are in metastable high-energy state. When the conditions are right, the particles agglomerate and become the agglomeration body with the relatively weak force of gravity. Under the relative strong action of the chemical bond, the materials agglomerate as a whole to become true agglomerates. Therefore, pulverization is a reversible process. If some way can be used to promote the pulverization to the positive direction, it is possible to obtain the products with finer particle size and larger specific surface area. In this way, the pulverization efficiency can be improved and the energy consumption and production costs can be reduced.  Under the guidance of the theory of mechanochemical effect in the grinding process, people find that certain substances (water, electrolyte, or surface-active agents, etc.) can be added in the grinding process to achieve this purpose. Since grinding is a process of gradual accumulation of energy, the energy on the surface of the particles and cracks become more and more as the grinding time goes. The formation of the charged groups of the unsaturated covalent bond will contribute to the secondary reunion of the particles. After adding the grinding aid, the grinding aid will adsorb on the active surface of the particles and balance tariff to shield the agglomeration force and prevent the coalescence of the powder.
Third, the chemical modification of the mechanical force is the application of the mechanochemical effects in the modification process of the powder surface in the grinding process.