Evaluation of the Use of Recycled Vegetable Oil as a Collector Reagent in the Flotation of Copper Sulfide Minerals Using Seawater

Felipe Arcos,Lina Uribe

doi:10.3390/recycling6010005

Abstract

Considering sustainable mining, the use of seawater in mineral processing to replace conventional water is an attractive alternative, especially in cases where this resource is limited. However, the use of this aqueous medium generates a series of challenges; specifically, in the seawater flotation process, it is necessary to adapt traditional reagents to the aqueous medium or to propose new reagents that achieve better performance and are environmentally friendly. In this research, the technical feasibility of using recycled vegetable oil (RVO) as a collector of copper sulfide minerals in the flotation process using seawater was studied. The study considered the analysis of the metallurgical indexes when different concentrations of collector and foaming reagent were used, considering as collectors the RVO, potassium amyl xanthate (PAX) and mixtures of these, in addition to the methyl isobutyl carbinol (MIBC) as foaming agent. In addition, it was evidenced that the best metallurgical indexes were achieved using 40 g/t of RVO and 15 g/t of MIBC, which corresponded to an enrichment ratio of 6.29, a concentration ratio of 7.01, a copper recovery of 90.06% and a selectivity index with respect to pyrite of 4.03 and with respect to silica of 12.89. Finally, in relation to the study of the RVO and PAX collector mixtures, it was found that a mixture of 60 g/t of RVO and 40 g/t of PAX in the absence of foaming agent presented the best results in terms of copper recovery (98.66%) and the selectivity index with respect to pyrite (2.88) and silica (14.65), improving PAX selectivity and recovery compared to the use of RVO as the only collector. According to these results, it is possible to conclude that the addition of RVO improved the selectivity in the rougher flotation for copper sulfides in seawater. This could be an interesting opportunity for the industry to minimize the costs of the flotation process and generate a lower environmental impact.

Highlights

Froth flotation is one of the most widely used physicochemical methods of concentrating minerals in the mining industry today because of the high capacity and efficiency it offers in the process of obtaining metals [1]
It is possible to conclude that the addition of recycled vegetable oil (RVO) improved the selectivity in the rougher flotation for copper sulfides in seawater
Pyrite recovery in this study was similar to that obtained using the conventional collectors. Taking into account these considerations, this research proposes to study a recycled vegetable oil as a collector of copper sulfide minerals in the flotation process in seawater in order to contribute to reduce the toxic collector used in minerals processing and to find a different type of application of this waste This study considered the analysis of the metallurgical indexes when different concentrations of collector and foaming reagent were used, considering as collectors the RVO, potassium amyl xanthate (PAX) and mixtures of these, in addition to the methyl isobutyl carbinol (MIBC) as foaming agent

Summary

Introduction

Froth flotation is one of the most widely used physicochemical methods of concentrating minerals in the mining industry today because of the high capacity and efficiency it offers in the process of obtaining metals [1]. Among the different collectors currently available in the copper mining industry, the xanthates are widely used in the flotation of minerals such as common sulfides (Cu, Mo, Pb, Zn, Co and Ni) and native metals (Cu, Ag, Au, etc.). The xanthates are ionic collectors and contain a hydrophilic polar group (affinity with water) attached to a chain of hydrocarbons that turns out to be the hydrophobic part. Due to their strong ionic powers, xanthates have negative effects to the biota and health hazards to human and animals [3,4,5], and they become a major problem at the time of handling and disposal of the waste generated by the flotation [6]. The efforts to reduce the harmful effects of these are focused on the search to develop a “green” collector, or environmentally friendly, that reduces or inhibits the generation of toxic substances

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Results

Conclusion