Effect of particle shape and roughness of talc mineral ground by different mills on the wettability and floatability

In this study, shape characteristics of talc particles produced by ball, rod and autogenous mills were investigated using Scanning Electron Microscope (SEM) and expressed by the shape descriptors such as elongation, flatness, roundness and relative width by measuring on the particle projections in two dimensions (2D). Approximately, 139 particles were measured for image analysis from each mill product. Surface roughness values of talc mineral have been expressed by the parameters of Ra value on the pelleted surfaces of the particles by employing Surtronic 3+ instrument. The wettability characteristics (γc) of talc mineral, produced by three different mills, were also determined by microflotation and the contact angle measurement techniques using the EMDEE MicroFLOT cell and Rame-Hart goniometer, respectively. Some correlations were established between the shape properties, surface roughness values and the wettability characteristics. The results have shown that elongation and smoothness helped to increase the hydrophobicity, while roundness and roughness caused a decrease in hydrophobicity or floatability for the talc mineral studied.