## 3 Results and Discussion
### Microwave Treatment  
#### 3.3.1 Effect of Microwave Treatment on Impurities Phases  
The effect of microwave treatment on the impurity phase was investigated using XRD, SEM, and EDX analyses (Figures 9 and 10). The studied samples included untreated samples and microwave-traded samples with various irradiation times (10, 20, 30, 40, and 50 min) to identify phase changes during the microwave treatment. Figure 9a-e presents the XRD results of the untreated sample (at the bottom), and microwave-treated samples for different irradiation times (at the top). The results showed significantly higher X-ray intensities for samples treated for 10 min (Figure 9a), than for untreated samples. However, no phase change was detected after microwave treatment because the irradiation time and pyrophyllite sample temperature were not sufficient to cause a phase change. A phase change from pyrite (Fe\({}_{2}\)) to pyrrhotite (Fe\({}_{7}\)S\({}_{8}\)) was detected after 20 min of microwave treatment (Figure 9b). The sample exhibited higher intensities than the sample treated for only 10 min. These findings are consistent with the previous literature [21; 30; 34; 35], suggesting that microwave treatment can indeed convert pyrite into ferromagnetic phases. Moreover, the X-ray intensity of the sample heated for 30 min was notably higher than that of the sample treated for 10 and 20 min (Figure 9c). The observed increase can be \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Feed Size (mm)**} & \multirow{2}{*}{**Products**} & \multirow{2}{*}{**Yield**} & \multicolumn{2}{c}{**Assay \%**} & \multicolumn{2}{c}{**Recovery (\%)**} \\ \cline{3-7}  & & & **wt. \%** & **Fe\({}_{2}\)O\({}_{3}\)** & **Al\({}_{2}\)O\({}_{3}\)** & **Fe\({}_{2}\)O\({}_{3}\)** & **Al\({}_{2}\)O\({}_{3}\)** \\ \hline \multirow{3}{*}{\(-0.250\) + 0.045} & Conc. & 76.5 & 0.42 & 26.02 & 22.95 & 79.49 \\  & Tail. & 23.5 & 4.59 & 21.85 & 77.05 & 20.51 \\  & Total & 100 & 1.40 & 25.04 & 100 & 100 \\ \hline \multirow{3}{*}{\(-0.125\) + 0.045} & Conc. & 76.7 & 0.40 & 26.04 & 21.91 & 79.76 \\  & Tail. & 23.3 & 4.69 & 21.75 & 78.09 & 20.24 \\  & Total & 100 & 1.40 & 25.04 & 100 & 100 \\ \hline \multirow{3}{*}{\(-0.250\) + 0.075} & Conc. & 75.04 & 0.57 & 25.87 & 30.55 & 77.52 \\  & Tail. & 24.96 & 3.90 & 22.55 & 69.45 & 22.48 \\  & Total & 100 & 1.40 & 25.04 & 100 & 100 \\ \hline \multirow{3}{*}{\(-0.125\) + 0.075} & Conc. & 76.56 & 0.46 & 25.98 & 25.16 & 79.43 \\  & Tail. & 23.44 & 4.47 & 21.97 & 74.84 & 20.57 \\  & Total & 100 & 1.40 & 25.04 & 100 & 100 \\ \hline \multirow{3}{*}{\(-0.075\) + 0.045} & Conc. & 77 & 0.51 & 25.93 & 28.05 & 79.74 \\  & Tail. & 23 & 4.38 & 22.06 & 71.95 & 20.26 \\  & Total & 100 & 1.40 & 25.04 & 100 & 100 \\ \hline \multirow{3}{*}{\(-0.045\)} & Conc. & 78 & 0.61 & 25.83 & 33.99 & 80.47 \\  & Tail. & 22 & 4.2 & 22.23 & 66.01 & 19.53 \\ \cline{1-1}  & Total & 100 & 1.40 & 25.04 & 100 & 100 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Fe\({}_{2}\)O\({}_{3}\) and Al\({}_{2}\)O\({}_{3}\) recovery in non-magnetic concentrate for different pyrophyllite sizes. attributed to the prolonged irradiation time and higher temperature of the pyrophyllite samples. Additionally, the results indicated a phase change in the pyrite (FeS2), which was transformed into pyrrhotite (Fe2S), while the hematite (Fe2O3) was converted into magnetite (Fe3O4). This finding aligns with previous research [21, 30, 35], which documented the phase change in pyrite and hematite into more ferromagnetic phases after 30 min of microwave treatment. Similarly, the X-ray intensities after a microwave treatment of 40 min remained relatively similar to those obtained after 30 min, as shown in Figure 9d. The results indicate a slowing rate of increase in sample temperature. Consequently, the phase change persisted, with pyrite converting to pyrrhotite and hematite (Fe2O3) to magnetite (Fe3O4), confirming  
Figure 9: XRD patterns for the untreated pyrophyllite and the microwave-treated samples. that microwave treatment after 40 min had the same effect as 30 min.