## 3 Results
### Electroflotation of Clays in NaCl Solutions
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Test** & **Clay Type** & **NaCl, M** & \(\mathbf{t_{EF_{r}}}\) & \(\mathbf{E_{cell}}\), \(\mathbf{V}\) & \(\mathbf{I_{cell}}\), \(\mathbf{A}\) & \(\mathbf{I_{cell}}\), \(\mathbf{A}\) & \%\(\mathbf{R_{MF}}\) \\ \hline
1 & & 0.1 & 10 & 10 & 0.14 & 0.05 & 1.49 \\
2 & & 0.3 & 15 & 15 & 0.17 & 0.05 & 43.52 \\
3 & & 0.5 & 20 & 20 & 0.40 & 0.03 & 72.68 \\ \hline
4 & & 0.1 & 10 & 10 & 0.15 & 0.03 & 2.37 \\
5 & Kaolinite & 0.3 & 15 & 15 & 0.23 & 0.04 & 45.72 \\
6 & & 0.5 & 20 & 20 & 0.80 & 0.03 & 88.44 \\ \hline
7 & & 0.1 & 10 & 10 & 0.40 & 0.04 & 2.33 \\
8 & & 0.3 & 15 & 15 & 0.56 & 0.04 & 31.36 \\
9 & & 0.5 & 20 & 20 & 0.71 & 0.05 & 67.36 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Operational and response parameters obtained for the electrofolotation of clays using a modified Hallimond tube with an anode and cathode made of Ti Gr. 2. Figure 5: Modified Hallimond tube, (a) before and (b) after the electrofolotation process of clays. Table 2 summarizes the electroflotation parameters for both kaolinite and montmorillonite and their mixtures under similar electroflotation times, cell voltages, and NaCl concentrations. From Table 2, it is observed that for the three cases of clays (alone and mixtures), lower electrochemical conditions of time, cell voltage, and NaCl concentration promote lower electroflotation efficiencies between 1.4 and 2.5%. However, this efficiency parameter increases with the increase of the electrochemical conditions, reaching efficiencies higher to 65%. These results are directly related to the increase in the cell voltage, which increases the cell current, thus promoting a major generation of bubbles on the electrodes, in addition to an increase in the electroflotation time. Both parameters are related to [PERSON]'s law. Moreover, it is also interesting to observe the effect of the NaCl concentration, which, although used to obtain a solution of high conductivity, would also promote corrosion on the electrodes. Under the optimal electroflotation conditions, the results show higher electroflotation efficiencies for kaolinite, reaching a value of 88.44%, compared to montmorillonite and the mixture of clays. These results are directly related to changes on the rheology and froth stability, where the swelling clays like montmorillonite accommodate large amounts of adsorbed water compared with non-swelling clays like kaolinite [42], adversely affecting the electroflotation performance. Additionally, these lower electroflotation efficiencies obtained for montmorillonite and the mixture of both clays are related to the increase in pulp viscosity, which, for example, increases from approximately 1 mPa\(\cdot\)s for kaolinite to 8.8 mPa\(\cdot\)s for montmorillonite under similar clay concentrations [43], thereby decreasing the electroflotation process. Therefore, despite the relatively short duration of the electroflotation experiments, the results could be promising, reveling acceptable recovery rates of clays from electroflotation assays in saline environments such as solutions with salt concentrations equivalent to seawater. However, continuous evaluation of the system is essential to investigate potential variations in these parameters over longer electroflotation periods, as well as the influence of the multiple ions typically observed in seawater.