Characterizing Frothers through Critical Coalescence Concentration (CCC)95-Hydrophile-Lipophile Balance (HLB) Relationship

Abstract

Frothers are surfactants commonly used to reduce bubble size in mineral flotation. This paper describes a methodology to characterize frothers by relating impact on bubble size reduction represented by CCC (critical coalescence concentration) to frother structure represented by HLB (hydrophile-lipophile balance). Thirty-six surfactants were tested from three frother families: Aliphatic Alcohols, Polypropylene Glycol Alkyl Ethers and Polypropylene Glycols, covering a range in alkyl groups (represented by n, the number of carbon atoms) and number of Propylene Oxide groups (represented by m). The Sauter mean size (D 32 ) was derived from bubble size distribution measured in a 0.8 m 3 mechanical flotation cell. The D 32 vs. concentration data were fitted to a 3-parameter model to determine CCC95, the concentration giving 95% reduction in bubble size compared to water only. It was shown that each family exhibits a unique CCC95-HLB relationship dependent on n and m. Empirical models were developed to predict CCC95 either from HLB or directly from n and m. Commercial frothers of known family were shown to fit the relationships. Use of the model to predict D 32 is illustrated.

Classification of Flotation Frothers

“…The trend-type correlative classifications of frothers shown in Figure 17 are equivalent because HLB/MW and CCC (Figure 7) are well related [22,42].…”

“…The scale of HLB is given in Table 4. The HLB values for organic frothers can be found in many papers (e.g., [22]). Table 4.…”

“…CCC is a parameter which indicates the frother concentration needed to prevent bubbles coalescence in an aqueous solution. The value of CCC can be either read-off from the bubble size-concentration curve or evaluated using HLB and MW [2,22,42]. Since the change of the bubble size in the vicinity of CCC is not sharp, usually CCC 95 , that is the frother concentration at which the average bubble size drops 95% is used.…”

Optimizing Performance of SABC Comminution Circuit of the Wushan Porphyry Copper Mine—A Practical Approach

“…Over the past decade, methodologies for optimizing grinding and flotation plants using plant data together with semi-empirical sub-process models have been developed by research groups at the Julius Krutschnitt Minerals Research Centre (JKMRC) (Brisbane, Australia), University of Cape Town (Cape Town, South Africa), and McGill University (Montreal, QC, Canada) [6][7][8][9][10][11][12][13]. The culmination of the work done by JKMRC was the JKSimMet simulation model developed by JKTech (the technology transfer company of JKMRC).…”

Concentration at the Minimum Bubble Velocity (CMV) for Various Types of Flotation Frothers

“…This influence has to be experimentally determined in terms of the most efficient range of concentrations, where desired liquid/gas interface properties, triggering useful frothers' features and allowing their classification, can be achieved. The experimentally determined parameters, which are commonly used for these purposes, are for example, the concentration at the minimum bubble velocity (CMV) [1][2][3], the critical coalescence concentration (CCC) [4][5][6], the concentration at half of the maximum foam height (CMH) [7] or the dynamic frothability index (DFI) [8][9][10]. Since all these parameters depend mainly on the properties of the liquid/gas interface, the corresponding characteristic frother concentration values can vary strongly, depending on the frother's family (type) and carbon chain length.…”