ANALYSIS OF EFFECT OF MAIN VARIABLES DETERMINING THE BEHAVIOR SUSPENSIONS RHEOLOGICAL LIMONITIC

Abstract

The present research paper studies the rheological properties of limonitic suspensions in the ore feed to the Pressure Acid Leach (PAL) process in Moa. Two ore samples with significantly different chemical characteristics were selected. The samples were collected in Moa Oriental ore body (Area # 30) and Moa Occidental ore body (Area # 12) in order to prepare the required ore slurries following the same procedure that is currently used by industrial facilities. The first part of the experiment included a physical-chemical characterization of the samples using the following techniques: particle size analysis using a particle analyzer, stability tests to determine the points of zero charge and x-ray fluorescence analysis to determine chemical composition. Afterward, a statistical design of experiments 2k was used to evaluate the effects of percent solids (% S), chemical composition (Nrmin), difference of pH (p.c.c-pH) and particle size distribution (s) and their interactions on the apparent viscosity of the suspension (µ) taking into consideration the operating band of the Process Plant. The results indicate that all suspensions had a non-Newtonian behavior that matches the Bulkley-Herschel rheological model. On the other hand, it was determined that with the exception of the % solids, the remaining factors and several interactions among two or three of them have a significantly high effect on the apparent viscosity of suspensions within the defined interval for each variable.