In this paper, a scheme of flotation frothers classification is presented. The scheme first indicates the physical system in which a frother is present and four of them i.e., pure state, aqueous solution, aqueous solution/gas system and aqueous solution/gas/solid system are distinguished. As a result, there are numerous classifications of flotation frothers. The classifications can be organized into a scheme described in detail in this paper. The frother can be present in one of four physical systems, that is pure state, aqueous solution, aqueous solution/gas and aqueous solution/gas/solid system. It results from the paper that a meaningful classification of frothers relies on choosing the physical system and next feature, trend, parameter or parameters according to which the classification is performed. The proposed classification can play a useful role in characterizing and evaluation of flotation frothers.

This paper presents the determination of a concentration at the minimum bubble velocity (CMV) for different types of frothers, such as straight and branched alkyl chain aliphatic alcohols, 1,ω-diols, poly(propylene glycol) and poly(ethylene glycol) alkyl ethers, n-alkyltrimethylammonium bromides, commercial frothers and others. The values of terminal rise bubble velocity were reviewed from the experimental data published in the literature for two different types of columns, i.e., a short PAS (used in Polish Academy of Sciences) of height (35 cm) and a long McGill of height (350 cm). The obtained empirical equation is universal and allows one to rapidly and accurately determine the CMV for all surfactants. The proposed empirical model can also be used to predict the terminal bubble velocity–frother concentration curve by knowing the maximum and minimum terminal velocities, as well as the values of CMV. Assessment and usefulness of frother characterization parameters (i.e., concentration at the minimum bubble velocity (CMV), dynamic frothability index (DFI) and critical coalescence concentration (CCC)) were shown in the flotation of coal.

Separation curves such as kinetic (recovery R versus process time t), limits (kinetic constant k versus maximum recovery R _max), incentive (R vs incentive parameter i), and arrheniusan (ln k vs 1/energy - for a regent concentration (i = c) being kTln(c/c _o)), were characterized and discussed. Their usefulness for flotation was described and relations between the curves were presented. All the separation curves provide valuable parameters. The arrheniusan curves are exceptionally useful because they deliver activation energy, expressed in the terms of energy, a parameter indicating how well a separation system responds to a change of an incentive parameter. The incentive parameter can be temperature, reagent concentration, pH, particles size and many others.

E3S Web of Conferences, open access proceedings in environment, energy and earth sciences

E3S Web of Conferences, open access proceedings in environment, energy and earth sciences

Hallimond tube flotation of different origins pyrites (coal-derived, Rio Tinto and Huanzala) and copper –bearing shale, having dif - ferent hydrophobicities determined by contact angle, were investigated in water and aqueous solutions of butyl diethylene glycol ether. Pyrites flotation depended on hydrophobicity, particle size fraction and frother concentration. Three regions of the yield-frother concentration plot were distinguished: Jones-Ray region at low frother concentration with decreasing yield due to entopic effects, Ly - ster region at medium frother concentration with increasing yield due to decreasing film stability and Zisman region at high frother concentration with decreasing yield due to surface tension drop. The flotation kinetics in the form of 1st order specific rate, equal to the kinetic constant, was similar for all three pyrites and was equal to 0.032±0.002 min -1 , while their yield after 45 min flotation was dependent on pyrite origin.