## 3 Results and Discussion  
Values were obtained from solutions with concentrations in the range of ppm of 14 elements corresponding to REEs: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. There was no possibility of analyzing Y and Sc, since no patterns of these elements were available, and Pm was discarded since it does not exist in nature but only as results of atomic processes. From the analysis of the five materials, the average values found in the samples are shown in Table 7.  
In Figure 2, a chondrite-normalized plot [78] indicates enriched light REE patterns in all the samples. Samples had a negative Eu anomaly, with Eu/Eu * \(<\) 1 highest in sample C, a depression that often characterizes a reducing environment [79]. A.2, corresponding to magnetic separation tailings, was always higher in light REEs than A.1, B, and C, and only inferior to A.0 in terms of the amount of HREEs. Table 8 compares the concentration of each rare metal in the earth crust with the samples of ore (A.0) and the flotation tailing (A.1) from the same treatment. Flotation tailings have lower proportions than \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Element** & **A.0 (ppm)** & **A.1 (ppm)** & **A.2 (ppm)** & **B (ppm)** & **C (ppm)** \\ \hline La & 70.18 & 3.85 & 96.51 & 12.82 & 19.13 \\ Ce & 144.72 & 6.08 & 137.14 & 21.06 & 37.26 \\ Pr & 16.19 & 0.66 & 13.31 & 2.34 & 4.45 \\ Nd & 65.49 & 2.60 & 54.87 & 7.36 & 18.37 \\ Sm & 12.5 & 0.63 & 12.31 & 1.26 & 3.62 \\ Eu & 3.04 & 0.17 & 3.49 & 0.37 & 0.78 \\ Gd & 9.19 & 0.57 & 13.51 & 1.11 & 3.62 \\ Tb & 1.68 & 0.08 & 2.00 & 0.12 & 0.49 \\ Dy & 8.75 & 0.54 & 12.44 & 0.69 & 2.80 \\ Ho & 1.82 & 0.12 & 2.98 & 0.11 & 0.57 \\ Er & 4.44 & 0.45 & 9.45 & 0.26 & 1.63 \\ Tm & 0.64 & 0.06 & 1.48 & 0.03 & 0.22 \\ Yb & 4.18 & 0.44 & 9.13 & 0.16 & 1.33 \\ Lu & 1.69 & 0.07 & 1.19 & 0.03 & 0.19 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Results of the analysis of five materials. Figure 2: Chondrite-normalized REE plot for materials from iron ore mining. the Earth's crust, indicating that most of the content remains in the concentrated ore. The enrichment factor presents the ppm of the element in the ore relative to the ones present in the Earth's crust. As ore concentrates most of the REEs, it could be an alternative as a base element in the production of rare earths, specifically LEEs such as Pr, Ce, and Eu. The use of ore concentrate for the extraction of rare earths must be evaluated, as it has a higher value as a source of iron. However, it would be interesting to monitor the behavior of rare earths throughout the iron and steel process to check their distribution in the liquid steel or the different wastes generated (slag, sludge, etc.). Table 9 compares concentrations in the different tailing analyses and a mean value in the bastnasite and the monazite minerals of each element. The values in bold indicate the highest content in each element among all the materials collected. In terms of these values, the last column has the proportion of the highest content in each element for the materials studied with respect to the minimum required for bastnasite or monazite to be exploitable; for example, in the case of magnetic separation tailing A.2, the percentage of Eu obtained in the flotation tailings waste ore was 24.65% of the total Eu contained in monazite ores and 11.90% of the total REEs obtained from bastnasite ores.