Variation of the Specific Speed of Fracture of the Coarse Faction Due to the Presence of Fines in Feeding in SAG Grinding

The experimental results obtained in the laboratory are presented, where under controlled semi-autogenous grinding (SAG) conditions, a single-size siliceous ore material was ground (12.5 mm > d100 > 9.5 mm) to which a pulp prepared from the same material with different fine concentrations below 200 mesh (d100 = 75 um), this being considered a polluting phase. The aim of the research is to determine the influence on the fracture kinetics of coarse particles under the premise that the presence of fines in a pulp modifies the rheological behavior of an initially Newtonian-type fluid such as water to a non-Newtonian one, as has been showing the mineral pulps. Initially, and due to the requirement of knowing the rheological response of the polluting pulp, 7 samples were formulated. The apparent viscosity values were obtained from tests carried out considering a shear rate of 22 s−1. The results obtained show an inversely proportional relationship between the presence of fines and the specific fracture rates of the coarse particles.