Polysaccharides-based pyrite depressants for green flotation separation: An overview

Abstract

Froth flotation is an essential processing technique for upgrading low-grade ores. Flotation separation would not be efficient without chemical surfactants (collectors, depressants, frothers, etc.). Depressants play a critical role in the selective separation of minerals in that they deactivate unfavorable mineral surfaces and hinder them from floating into the flotation concentration zone. Pyrite is the most common and challenging sulfide gangue, and its conventional depressants could be highly harmful to nature and humans. Therefore, using available, affordable, eco-friendly polymers to assist or replace hazardous reagents is mandatory for a green transition. Polysaccharide-based (starch, dextrin, carboxymethyl cellulose, guar gum, etc.) polymers are one of the most used biodegradable depressant groups for pyrite depression. Despite the satisfactory flotation results obtained using these eco-friendly depressants, several gaps still need to be addressed, specifically in investigating surface interactions, adsorption mechanisms, and parameters affecting their depression performance. As a unique approach, this review comprehensively discussed previously conducted studies on pyrite depression with polysaccharide-based reagents. Additionally, practical suggestions have been provided for future assessments and developments of polysaccharide-based depressants, which pave the way to green flotation. This robust review also explored the depression efficiency and various adsorption aspects of naturally derived depressants on the pyrite surface to create a possible universal trend for each biodegradable depressant derivative.

Keywords

• Green flotation
• Pyrite depression
• Eco-friendly depressants
• Adsorption mechanisms