(2012), who reported that specific power consumption in a mechanical flotation cell increases with impeller speed. Figure 4 – Main effects of baffling (0: Stator only, 1: Baffles only) and Jg on mean Pjs The stator also promotes intense turbulent energy dissipation, which contributes to larger specific power draw values (Schubert, 2008; Kim et al., 2023). Conversely, although aeration is generally expected to reduce power draw (Arbiter et al., 1976; Nienow, 1997), this effect typically occurs when air is introduced at a constant impeller speed. In this study, the impeller speed was increased to reach Njs, which more than offset any potential power savings from aeration. Consequently, the overall effect of increasing Jg was an increase in Pjs. Baffling and Jg exhibited a strong interactive effect on Pjs, consistent with the interaction observed for Njs. This relationship is expected, as variations in power draw can be largely attributed to changes in impeller speed. Increasing Jg raises Njs, and consequently, Pjs increases as well. Because power scales exponentially with impeller speed (Newell & Grano, 2007), the sensitivity of Pjs to Jg depends strongly on the baffling configuration (Figure 5). Figure 5 – Effect of Jg on mean Pjs for stator (0) and baffles (1) arrangements With baffles, the system operates at relatively low Njs values. In this low-speed regime, power draw increases nearly linearly with impeller speed, so higher Jg (and therefore higher Njs) results in a moderate rise in power. In contrast, operation with the stator requires higher impeller speeds, where the power–speed relationship becomes exponential. As a result, increasing Jg in the
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