## 3 Results  
The results of the experimental study of the pH impact at the concentration of the chloride ions of 0.01 M on the lanthanum (III) cations recovery by ion flotation are shown in Table 1.  
Lanthanum (III) cations have the highest \(K_{dist}\), which is 513 in weakly alkaline medium at pH = 8.6. \(K_{dist}\) in the pH range of 4.0-6.75 does not exceed 10. The pH the start of removal is 7.8. As the pH of maximum recovery is significantly higher than the pH of lanthanum (III) hydroxide formation, which is 7.0, lanthanum hydroxides La(OH)\({}_{3}\) are flotated to froth. The pH of maximum recovery shifted towards higher values from 7.9 in nitrate medium to 8.6 at the sodium chloride concentration of 0.01 M.  
Metals cations distribution coefficients (\(K_{dist}\)) between froth pulp and chamber residue were calculated by \([Me^{3+}]_{org}\) concentration in the froth pulp relative to \([Me^{3+}]_{aq}\) concentration in chamber residue in accordance with formula:  
\[K_{dist}=\frac{\left[Me^{3+}\right]_{org}}{[Me^{3+}]_{aq}} \tag{1}\]  
The results of the experimental study of the pH impact at the concentration of the chloride ions of 0.01 M on the lanthanum (III) cations recovery by ion flotation are shown in Table 2. \begin{table}
\begin{tabular}{c c c c} \hline
**pH** & **[La\({}^{3+}]_{aq}\times 10^{4}\) mol/L** & **[La\({}^{3+}]_{org}\times 10^{3}\) mol/L** & **\(K_{distr}\)** \\ \hline
4.0 & 5.89 & 1.16 & 3.3 \\
4.9 & 5.11 & 1.46 & 4.0 \\
6.0 & 4.34 & 1.83 & 5.0 \\
6.7 & 2.49 & 1.92 & 8.3 \\
7.4 & 1.77 & 2.01 & 11.4 \\
7.8 & 1.57 & 2.07 & 13.8 \\
8.2 & 1.20 & 2.05 & 16.6 \\
8.7 & 0.98 & 2.11 & 20.5 \\
9.2 & 2.07 & 1.79 & 9.8 \\
9.7 & 10.01 & 0.86 & 1.3 \\ \hline \end{tabular}
\end{table} 
Table 2: The results of the experimental study of lanthanum (III) cations recovery to froth pulp in nitrate-chloride medium at the NaCl concentration of 0.05 M.  
\begin{table}
\begin{tabular}{c c c c} \hline
**pH** & **[La\({}^{3+}]_{aq}\times 10^{4}\) mol/L** & **[La\({}^{3+}]_{org}\times 10^{3}\) mol/L** & **\(K_{distr}\)** \\ \hline
4.0 & 5.89 & 1.16 & 3.3 \\
4.9 & 5.11 & 1.46 & 4.0 \\  
At the sodium chloride concentration of 0.05 M, the \(K_{distr}\) as a function of pH at the lanthanum (III) flotation does not differ from the similar one at the NaCl concentration of 0.01 M. In the acidic medium, there is no recovery. At pH > 6.0, \(K_{distr}\) increases from 5 to the maximum value, which is 20.5 at pH = 8.7. At maximum recovery pH = 8.7, the lanthanum (III) hydroxides are recovered to the froth as pH\({}_{\text{hydr}}\) = 7.0. The value of 6.2 is taken for pH the start of recovery. The La(OH)\({}_{3}\) hydroxides go to froth as pH\({}_{\text{compl}}\) = 6.28. The results of the experimental study of pH impact at the concentration of 0.01 M on the yttrium (III) cations recovery by ion flotation are shown in Table 3.  
When the yttrium (III) cations underwent flotation in acidic medium at the NaCl concentration of 0.01 M at pH < 6.7, recovery practically did not take place. A surge in \(K_{distr}\) is observed at pH 6.7. Maximum \(K_{distr}\) is 379 at pH 7.8, and, in the nitrate medium, 856 at pH 6.9. Chloride ions suppress the recovery of yttrium (III) cations to froth, and shift pH of maximum recovery towards higher values in the nitrate medium ranging from 6.9 to 7.8. When chloride ions are not found, the maximum recovery takes place in the form of YOH(DS)\({}_{2}\) at pH 6.9. If the chlorides' concentration is 0.01 M, recovery takes place in the form of Y(OH)\({}_{3}\), as the pH\({}_{\text{hydr}}\) and pH\({}_{\text{compl}}\) are 7.2 and 6.3, respectively. The results of the experimental study of the pH impact at the concentration of the chloride ions of 0.05 M on the yttrium (III) cations recovery by ion flotation are shown in Table 4.  
When concentration of sodium chloride increases to 0.05 M, the removal of yttrium (III) cations from the aqueous phase to froth decreased by a great extent. If pH ranges from 4.0 to 9.0, \(K_{distr}\) does not exceed 10.