## 3 Results and Discussion
### Repeated Tests  
In order to further validate test repeatability, repeated tests were carried out under the conditions employed as follows: a removing ammonium chloride and residual crystal water temperature of 400 \({}^{\circ}\)C; m(Sc\({}_{2}\)O\({}_{3}\)):m(NH\({}_{4}\)Cl) = 1:2.5; a holding time of 90 min; a heating rate of 12 \({}^{\circ}\)C/min; and an argon flow of 7.5 L/min. The repeated results are shown in Tables 2 and 3.  
These results in Table 2 show that the anhydrous scandium chloride molten salt index (scandium content and hydrolysis rate of scandium) of repeated experiments was superior to the conditions of resulted. Scandium chloride with the scandium content of 29.61% was obtained, and hydrolysis rate of scandium was 1.19%.This indicated that it was feasible to prepare high-purity scandium chloride using non-high-purity scandium chloride raw materials by the process of rapid temperature desorption of ammonium chloride to a certain temperature and residual crystal water, and the hydrolysis rate of scandium chloride in scandium chloride was low. Compared with the pure scandium chloride molten salt, the scandium content in the prepared scandium chloride was 29.61%, which was close to the theoretical scandium content in scandium chloride was 45/(45 + 35.5 \(\times\) 3) \(\times\)100% = 29.703%, and the purity was 29.61%/29.703 = 99.69%.  
Meanwhile, it is known from the results in Table 3 reveal that the content of other impurities in the anhydrous scandium chloride molten salt also lower and provide high quality scandium-bearing raw materials for the subsequent preparation of aluminum-scandium alloy.  
\begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Repeat**} & \multicolumn{2}{c}{**Scandium Content in Anhydrous**} & \multicolumn{1}{c}{**Hydrolysis Rate**} \\  & \multicolumn{2}{c}{**ScCl\({}_{3}\) Molten Salt**} & \multicolumn{1}{c}{**of Scandium**} \\ \hline
1 & 29.56 & 1.19 \\ \hline
2 & 29.62 & 1.18 \\ \hline
3 & 29.54 & 1.26 \\ \hline
4 & 29.66 & 1.21 \\ \hline
5 & 29.64 & 1.19 \\ \hline
6 & 29.59 & 1.24 \\ \hline
7 & 29.67 & 1.16 \\ \hline
8 & 29.59 & 1.16 \\ \hline Average & 29.61 & 1.19 \\ \hline \(Range\) (\(R=E_{\text{max}}-E_{\text{min}}\)) & 0.13 & 0.100 \\ \hline \(Arithmetic\) _mean error_ (\(\delta=\frac{\sum\limits_{i}^{N}|q_{i}|}{N}\)) & 0.039 & 0.027 \\ \hline \(Sum\) _square variation_ (\(\text{SS}=\sum\limits_{i=1}^{N}d_{i}^{2}=\sum\limits_{i=1}^{N}\left(E_{i}- \overline{E}\right)^{2}\)) & 0.015 & 0.01 \\ \hline \(Average\) _deviation_ (\(\text{MS}=\frac{\text{SS}}{f}\)) & 0.002 & 0.001 \\ \hline \(Standard\) _deviation_ (\(\text{s}=\sqrt{\frac{\sum\limits_{i}\left(E_{i}-\overline{E}\right)^{2}}{N-1}}= \sqrt{\text{MS}}\)) & 0.045 & 0.032 \\ \hline \end{tabular}
\end{table}
Table 2: Repeated tests results of preparing anhydrous scandium chloride (%).  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multicolumn{1}{c}{**Sc**} & \multicolumn{1}{c}{**Cl\({}^{-}\)**} & \multicolumn{1}{c}{**Fe\({}_{2}\)O\({}_{3}\)**} & \multicolumn{1}{c}{**SiO\({}_{2}\)**} & \multicolumn{1}{c}{**Al\({}_{2}\)O\({}_{3}\)**} & \multicolumn{1}{c}{** CaO**} & \multicolumn{1}{c}{**MgO**} & \multicolumn{1}{c}{**K\({}_{2}\)O**} & \multicolumn{1}{c}{**Na\({}_{2}\)O**} \\ \hline
29.61 & 70.12 & 0.001 & 0.04 & 0.008 & 0.006 & 0.008 & 0.006 & 0.002 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Main chemical composition analysis results of anhydrous scandium chloride (%).