Advancing phosphate ore minerals separation with sustainable flotation reagents: An investigation into highly selective biobased depressants

Abstract

Froth flotation has been a commonly employed technique to enrich natural ores by removing impurities based on the surface properties of minerals. This process involves the use of various reagents, including collectors, depressants, frothers, and activators, which are often chemically synthesized and may represent environmental risks. Therefore, there is a growing need to develop biobased reagents that offer more sustainable alternatives. The aim of this review is to provide a comprehensive assessment of the potential of biobased depressants as a sustainable alternative to traditional reagents in selective flotation process for phosphate ore minerals. To achieve this objective, the review investigates the extraction and the purification methods of different biobased depressants, analyzes the specific conditions for reagent interaction with minerals, and assess the biobased depressants' performance through a range of fundamental studies. These studies aim to (i) provide a better understanding of the adsorption behavior of some biobased depressants onto the surfaces of apatite, calcite, dolomite, and quartz comprised in different mineral systems by measuring their zeta potential and analyzing their Fourier transform infrared spectra before and after contact with these reagents, (ii) determine the depressants' adsorption amounts, (iii) evaluate their effect on the contact angle of bare minerals, and (iv) assess their ability to inhibit the flotation of the studied minerals. The outcomes revealed the potential use and the promising applicability of these unconventional reagents since their performance is comparable to that of conventional reagents. In addition to their good effectiveness, these biobased depressants have the added advantages of being cost effective, biodegradable, non-toxic, and ecofriendly. Nevertheless, further research and investigations are required to improve the selectivity and, consequently, the effectiveness of biobased depressants.

Keywords: Biobased depressants; Ecofriendly; Flotation reagents; Phosphate minerals; Polysaccharides; Selective separation.