Mineral cleavage nature and surface energy: Anisotropic surface broken bonds consideration
(School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China)
Abstract: The population of surface broken bonds of some typical sulfide, oxide and salt-type minerals which may belong to cubic, tetragonal, hexagonal, or orthorhombic system, were calculated. In terms of the calculation results, the cleavage natures of these minerals were analyzed, and the relationship between surface broken bonds density and surface energy was also established. The results show that the surface broken bonds properties could be used to predict the cleavage nature of most of minerals, and the predicted cleavage planes agree well with those reported in previous literature. Moreover, this work explored a rule that, surface broken bonds density is directly related to surface energy with determination coefficient (R2) of over 0.8, indicating that the former is a dominant factor to determine the latter. Therefore, anisotropic surface broken bonds density can be used to predict the stability of mineral surface and the reactivity of surface atoms.
Key words: surface broken bonds; cleavage; surface energy; pyrite; sphalerite; cassiterite; rutile; hematite