## 3 Results and Discussion
### Results of the Two-Stage Counter-Current Acid Leaching with the Addition of Hydrogen Peroxide
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Material**} & \multirow{2}{*}{**Cycle**} & \multicolumn{3}{c}{**Volume of the Solution after**} & & & & & & & & & & \\ \cline{3-11}  & & \multicolumn{2}{c}{**Leading (cm\({}^{3}\))**} & \multirow{2}{*}{**pH**} & \multicolumn{6}{c}{**Concentration of the Element in the Solution after Leaching (g/dm\({}^{3}\))**} \\ \cline{3-11}  & & & **I Stage** & & **Li Stage** & & **Co** & **Ni** & **Li** & **Cu** & **Mn** & **Fe** & **P** & **F** \\ \hline \multirow{4}{*}{III} & \multirow{2}{*}{1} & 4900 & - & 0.1 & 26.60 & 4.03 & 5.83 & 2.10 & 1.92 & 0.71 & 0.68 & 2.20 \\ \cline{3-11}  & & - & 6600 & 0.1 & 19.40 & 0.70 & 1.10 & 0.18 & 0.72 & 0.06 & 0.08 & 0.18 \\ \cline{1-1}  & \multirow{2}{*}{2} & 6000 & - & 0.4 & 38.80 & 3.18 & 5.14 & 1.51 & 1.64 & 0.54 & 0.64 & 1.60 \\ \cline{1-1}  & & - & 6500 & 0.1 & 19.80 & 1.10 & 1.28 & 0.24 & 0.86 & 0.07 & 0.07 & 0.16 \\ \cline{1-1}  & & 5860 & - & 0.4 & 38.10 & 3.57 & 5.35 & 1.60 & 1.81 & 0.56 & 0.62 & 1.59 \\ \cline{1-1}  & \multirow{2}{*}{3} & - & 6420 & 0.1 & 21.80 & 1.15 & 1.37 & 0.28 & 0.97 & 0.09 & 0.06 & 0.16 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: _Cont._ \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Material**} & \multirow{2}{*}{
\begin{tabular}{c} **The Initial Weight of the Battery Mass** \\ **or after-Leaching Sludge (g)** \\ \end{tabular} } & \multirow{2}{*}{**Cycle**} & \multicolumn{6}{c}{**Composition of the Battery Mass or after-Leaching Sludge (\%)**} \\ \cline{3-11}  & & & **Co** & **Ni** & **Li** & **Cu** & **Mn** & **Fe** & **P** & **F** \\ \hline \multirow{4}{*}{1} & \multirow{4}{*}{1000} & 0 & 9.33 & 9.83 & 3.64 & 2.73 & 8.70 & 0.31 & 0.84 & 3.22 \\ \cline{2-11}  & & 422 & 1 & 0.05 & 0.06 & 0.05 & 0.04 & 0.10 & 0.11 & 2.07 \\ \cline{2-11}  & & 440 & 2 & 0.22 & 0.20 & 0.08 & 0.14 & 0.17 & 0.16 & 0.16 & 1.92 \\ \cline{2-11}  & & 418 & 3 & 0.22 & 0.21 & 0.08 & 0.10 & 0.16 & 0.14 & 0.14 & 2.01 \\ \hline \multirow{4}{*}{II} & \multirow{4}{*}{1000} & 0 & 29.70 & 1.96 & 3.79 & 1.53 & 0.81 & 0.39 & 0.49 & 1.84 \\ \cline{2-11}  & & 394 & 1 & 0.37 & 0.02 & 0.05 & 0.05 & 0.01 & 0.11 & 0.17 & 1.33 \\ \cline{2-11}  & & 404 & 2 & 0.71 & 0.04 & 0.06 & 0.06 & 0.01 & 0.10 & 0.19 & 1.38 \\ \cline{2-11}  & & 405 & 3 & 0.75 & 0.07 & 0.06 & 0.07 & 0.01 & 0.19 & 0.19 & 1.35 \\ \hline \multirow{4}{*}{III} & \multirow{4}{*}{381} & \multirow{4}{*}{1} & \multirow{4}{*}{0.30} & \multirow{4}{*}{0.03} & \multirow{4}{*}{0.03} & \multirow{4}{*}{0.01} & \multirow{4}{*}{0.01} & \multirow{4}{*}{0.14} & \multirow{4}{*}{0.07} & \multirow{4}{*}{1.52} \\ \cline{2-11}  & & & & & & & & & & \\ \cline{2-11}  & & 373 & 2 & 0.48 & 0.04 & 0.04 & 0.02 & 0.02 & 0.13 & 0.09 & 1.47 \\ \cline{2-11}  & & 369 & 3 & 0.33 & 0.03 & 0.03 & 0.01 & 0.01 & 0.08 & 0.08 & 1.49 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Comparison of the results of analyses of the battery masses and sludges formed after the two-stage counter-current leaching. Figure 3: _Cont._Figure 3: _Cont._  
Figure 4: _Cont._  
Figure 3: XRD analyses of the masses after leaching—Material II and Material III. Figure 4: _Cont._  
After analyzing the results, it can be concluded that for Material I, the vast majority of cobalt, nickel, lithium, copper, manganese, iron, phosphorus and fluorine was transferred into the solution after the two-stage counter-current leaching process. The battery mass remaining after the leaching contained \(<\)1% of cobalt and \(<\)0.01% of nickel, lithium, manganese and copper. In the case of iron and phosphorus, the content in the sludge did not exceed 0.2%. Fluorine, on the other hand, accounted for 1.33-1.37% of the sludge remaining after the leaching. In the case of Material II, the composition results were almost identical to those obtained in the case of Material I. However, for Material III, the battery mass remaining after the leaching contained \(<\)0.5% of cobalt and \(<\)0.005% of nickel, lithium, manganese and copper, while the iron and phosphorus amount was \(<\)0.1%.