Frothers in flotation: A review of performance and function in the context of chemical classification

The significance of frothers in the context of mineral flotation is widely recognized, particularly in relation to their impact on bubble size and dispersion, coalescence inhibition, as well as the structure and stability of the froth. All these parameters hold substantial importance in determining the feasibility of the process including the overall recovery of valuable minerals and concentrate grade in flotation process. This review aims to offer a comprehensive overview of the importance of frothers in the flotation process focusing on their performance and function in the context of their chemical classification. The characterisation of flotation frothers is discussed, focusing on the most often used parameters including molecular weight, hydrophilic-lipophilic balance (HLB), dynamic frothability, and interfacial tension measurement. Additionally, the importance of advanced characterisation techniques such as single rising bubble experiments, high-speed video microscopy and infrared reflection absorption spectroscopy (IRRAS) is highlighted. Finally, the application of biodegradable and environmentally friendly biosurfactants such as rhamnolipids as "green frothers" in enhancing flotation rates is outlined.