Statistical evaluation of olivine flotation in the presence of dextrin

Abstract

Olivine (Mg,Fe)2SiO4) is an important industrial raw material especially for metallurgical processes such as foundry sand, slag conditioning, production of refractories and iron ore pellets. Olivine alters throughout the geological ages to serpentines (e.g., lizardite) containing high rate of crystal water, in turn high Loss on Ignition (LOI) value. The LOI value of olivine ore is the major specification for metallurgical areas: thermal properties of olivine deteriorate at high LOI values. This study was performed to elucidate the effect of the concentration of dextrin and Na-oleate together with pH and conditioning time on olivine flotation and rejection of lizardite. Ore sample was found to contain olivine and forsterite as major rock forming minerals together with pyroxenes, lizardite and chromite as accessory minerals. Experimental design was made using Taguchi approach and experimental results were evaluated by ANOVA test. High LOI product was obtained in the froth indicating the higher floatability of lizardite as compared with olivine and forsterite. Collector concentration was found to be most effective tested variable on flotation. Lizardite could not be rejected efficiently by using dextrin as modifying agent.