Implications of fine grinding in mineral processing - Mechanochemical approach

Fine grinding of minerals may change physical and chemical properties of the material to the extent that has to be considered in laboratory verification work or processing work in the industrial plant. The ground material is mechanically activated by increase of both: specific surface energy and elastic strain energy. The activation energy can then be dissipated through different mechanisms, such as: polymorphic transformation, mechanochemical decomposition or synthesis. The thermodynamical principles and kinetics mechanisms responsible for the relaxation modifications are thoroughly discussed. Important factors such as: Reaction triggering dimension, action of shear stresses, surface groups activity, product reactivity, etc. are described. A short survey on comminution by fine grinding is also presented.