Theoretical Bases of Mechanochemical Processes in Ball Milling

Farit Kh. Urakaev

Institute of Mineralogy and Petrography, Siberian Branch, Russian Academy of Sciences,

prospekt akademika Koptyuga, 3, Novosibirsk, 630090, Russia

Abstract

For the models built up on the basis of the non-linear elastic plastic theory describing the collisions of solids, parameters of impact interaction between the milling tools and the material to be treated have been calculated for a series of comminuting devices, i.e., different types of ball mills, etc. Pressure and temperature impulses at the contacts of the treated particles have been calculated. The equations describing the kinetics of contact melting and crystallization of the substances have been deduced on the basis of the obtained distributions of temperature and pressure impulses during impact-friction interaction of the particles treated in ball mills. Possible mechanisms of the formation of nanocrystal particles and of chemical reactions during the crystallization of thin films of a melt at high rates of local temperature changes in the near-contact regions have been studied. Generalized equations have been deduced for the kinetics rate constants of mechano-chemical reactions and for the mechanical activation of the substances in ball milling. Various examples are presented that deal with the application of the generalized kinetic equation to the calculations of ab initio rate constants of specific mechanochemical processes in ball milling. The obtained theoretical values have been compared with experimental results.