Comparing the Performance of the Use of Recycled Vegetable Oil and Biosolids as Collectors of Copper Sulfide Flotation and Their Effect on the Foam Stability

Abstract

Flotation is the traditional process used for concentrating sulfide ores, based on the differences in hydrophobicity exhibited by the minerals which are enhanced by collectors. Xanthates are the collectors widely used in the flotation of minerals such as common sulfides (Cu, Mo, Pb, Zn, Co, Ni) and native metals. However, xanthates have negative impacts on biota and pose a risk to human and animal health. This study explores recycled vegetable oils (RVO) and biosolids (BSs) as alternative collectors in mineral flotation. Tests at pH 8, conducted with an Edemet Cell, compared their performance with traditional xanthate collectors and assessed their impact on foam stability. Collectors were tested at dosages ranging from 20 to 100 g/ton, with 15 ppm of MIBC frother, while fixed dosages of 60 g/ton were used for kinetic and foam volume analysis. The results revealed that RVO and BSs exhibited greater selectivity in separating chalcopyrite from pyrite compared to Potassium Amyl Xanthate (PAX). Interestingly, RVO reduced foam volume when used alongside MIBC frother, while BSs had minimal impact on foam volume. In ores rich in chalcopyrite, RVO and biosolids significantly improved flotation kinetics, outperforming PAX. Synthetic samples also showed BS1 to have kinetics similar to the conventional collector. These findings suggest that RVO and biosolids have the potential to replace traditional collectors in cleaner flotation processes, promoting more environmentally responsible mining practices. Graphical Abstract: (Figure presented.) © The Minerals, Metals & Materials Society 2024.