Amphiphilic cellulose and surfactant mixtures as green frothers in mineral flotation. 1. Characterization of interfacial and foam stabilization properties

Amphiphilic cellulose and surfactant mixtures as green frothers in mineral flotation. 2. Flotation of chalcopyrite and Cu-containing tailings

“…Figure 8. Evolution of γ in the presence of pure reagents (note the change in the scale of y-axis) (Nuorivaara and Serna, 2020b) The results presented in Figure 8 showcase the differences between the interfacial behavior of small surfactant molecules and surface-active polymers. NF240 adsorbs rapidly on the interface, resulting in significant reductions to γ at short bubble lifetimes and low concentrations.…”

“…The air flow rate was set at 0.4 l/min with a manual control valve attached to a rotameter. (Nuorivaara and Serna, 2020a;Nuorivaara and Serna, 2020b) To measure the bubble size distribution, a sampling tube was immersed into the column, at the aqueous-phase level. The sampling tube was connected to a viewing chamber with a red background light and a glass screen.…”

“…The first experiments in this project were conducted with an aim to determine a suitable measurement protocol for characterizing the interfacial properties of commercial frothers, HPMC and their PS-mixtures. As mentioned in the Introduction, apart from studies directly connected to this research project (Nuorivaara and Serna, 2016;Rinne, 2018;Lamberti, 2019;Nuorivaara and Serna, 2020a;Nuorivaara and Serna, 2020b;Nuorivaara and Serna, 2020c) no prior work has studied the interfacial properties of surface-active polymers with methods utilized in frother studies. Thus, the findings of Publication I could be regarded as identifying a reliable method for measuring and interpreting the results of surface-active polymers at the air-liquid interface.…”

“…Similar to pure HPMC10k, the decrease of γ is accelerated by increasing the total concentration of Mix10k formulations. (Nuorivaara and Serna, 2020b) Evidently, the rate of γ change and its final value depend on the total concentration of the applied frother formulation and the ratio between the polymer and the surfactant (when using PS-mixtures). Nonetheless, there are clear indications of synergistic acceleration in γ dynamics observed in the presence of PS-mixtures.…”

“…3) To connect the identified differences in fundamental properties to flotation performance by conducting flotation experiments and analyzing the resulting recoveries, grades, separation efficiencies (SE) and flotation kinetics based on existing information regarding frother, bubble and froth properties as well as their impact on flotation performance. Since there is no prior information of cellulose derivatives being used as flotation frothers (to the best knowledge of the author's knowledge) apart from publications by the author and his supervisor (Nuorivaara and Serna, 2016;Nuorivaara and Serna, 2020a;Nuorivaara and Serna, 2020b;Nuorivaara and Serna, 2020c) and Master's theses that were written under the guidance of the author and his supervisor (Rinne, 2018;Lamberti, 2019), there is not sufficient information regarding the synthesis of new cellulose chemistries for this application. Thus, this aspect was considered beyond the scope of this research.…”