Flotation Frothers: Review of Their Classifications, Properties and Preparation

Abstract

Abstract:The importance of frothers in flotation is widely acknowledged, particularly in terms of their role with respect to bubble size, and the stability and mobility of the froth phase. These factors play a significant role in the kinetic viability of the process, and the overall recovery and the grade that can be achieved from a flotation cell or circuit. About 60 years ago, Wrobel [1] presented a comprehensive review of flotation frothers, their action, properties and structures. However, during recent six decades flotation reagent technology has undergone considerable evolutions and innovations. The aim of the present review is to provide an updated, comprehensive database comprising recent developments in flotation frother technology as well as some historical aspects. Different types of flotation frothers are discussed regarding to their classifications, properties, and preparation methods. New classification schemes have been suggested in parallel with introducing new characterization criteria. New classes of frothers are actually conventional frothers modified by incorporating certain functional "group" or "atoms" into their molecular structure. Like particle surface modifiers, frothers are also influenced by biotechnology, leading to introducing a new class of frothers named as "biofrothers".

Classification of Flotation Frothers

“…Frothers with wetting properties [7][8][9] Wetting reagents [8][9][10][11][12][13][14][15][16][17][18] Emulsification reagents (oil in water) 13-15 Detergents 15-18 Solubilisation reagents…”

“…Therefore, there is a classification of frothers based on their ability to dissociate in aqueous solutions. Their dissociation depends on pH and therefore the frothers are classified into acidic, neutral and basic, that is cationic, anionic and non-ionic [15,23] (Table 5). This is a no-numerical value classification type.…”

“…Table 5. Classification of frothers according to their pH-sensitivity [15,23]. Solubility of frothers influences the flotation performance [24].…”

“…Crozier [25] divided frothers into completely miscible and slightly soluble. Such reagents as aliphatic alcohols, cresylic acids, alkoxy paraffins and non-ionic polypropylene glycol ethers belong to the slightly soluble group of frothers, while completely soluble are polyglycols and polyglycol ethers [15].…”

“…As a result, there are numerous classifications of frothers. For instance, Khoshdast and Sam [15] classified frothers taking into account their (i) pH-sensitivity; (ii) solubility; (iii) frothing/collecting properties; and (iv) selectivity/frothing power. The classifications considering pH-sensitivity and solubility are obvious.…”