Facile determination of foamability index of non-ionic and cationic frothers and its effect on flotation of quartz

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

“…The values of CMC, CCC, CMH and CMV decrease as the number of carbons in the alkyl chain of surfactant increases. In the case of the CMC, the trend is related to the energy transfer of surface active molecules of frothers from the bulk solution to the micelle, while in the case of the CMV, CCC and CMH, the trend is related to the transfer of surface active molecules of frothers from the bulk to the surface [3,7].…”

“…The same classification can be made for any other flotation frothers utilizing their foaming properties. Table 4 shows that (i) the frother characterization parameters, e.g., CMV, CCC and CMH, can be easily determined by empirical equations proposed in this work for CCC and CMV as well as for CMH [7], and (ii) the equations can be successfully used to predict the terminal bubble velocity-concentration, bubble shape-concentration and foam height-concentration curves by knowing the maximum and minimum values of either bubble velocities and shapes or foam height, as well as the values of CMV, CCC and CMH. (Figure 13), by analogy the same attempt can be made to create the DFI-CMV diagram.…”

“…This empirical equation allows one to predict the values of the CMV from the number of carbons in the alkyl chain (C n ) for aliphatic alcohols, poly(ethylene glycol) alkyl ethers (for m = 1, 2 and 3), poly(propylene glycol) alkyl ethers (for m = 1, 2 and 3), n-alkyltrimethylammonium bromides (C n TAB) and 1,2-diols. The physicochemical characteristics of surfactants, e.g., the critical micelle concentration (CMC), the critical coalescence concentration (CCC), the concentration at half of the maximum foam height (CMH) and the concentration at the minimum bubble velocity (CMV) strongly depend on the alkyl chain length [2,3,7,18,27]. The values of CMC, CCC, CMH and CMV decrease as the number of carbons in the alkyl chain of surfactant increases.…”

“…Many authors have investigated the influence of surfactant type and concentration on the flotation performance (e.g., [7,9,[31][32][33][34][35][36][37][38][39][40][41]). An example involving coal flotation is shown in Figure 16.…”

“…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.…”