**4. Conclusions**

In this article, we investigated the possibility of concentrating rare-earth elements into red mud obtained by leaching dust from electrostatic precipitators used in bauxite charge sintering. We compared the chemical composition of the sinters and ESP dust formed during bauxite sintering in tubular rotary kilns. The sinter and the dust were analyzed for the content of rare earth elements. We also studied their association with various minerals of the materials used. The study of leaching of electric precipitation dust allows us to draw the following conclusions:


A technological scheme has been proposed for the removal of ESP dust from the cycle and its further comprehensive processing. Recovery of additional components from ESP dust will improve the efficiency of processing of bauxite raw materials in general and reduce the environmental footprint.

**Author Contributions:** Conceptualization, I.L. and L.C.; methodology, I.L.; validation, L.C., I.L.; formal analysis, A.S., D.V.; investigation, L.C., J.N.; resources, L.C., I.L.; data curation, I.L.; writing—original draft preparation, A.S. I.L.; writing—review and editing, A.S., D.V.; visualization, J.N., D.V.; supervision, L.C.; project administration, I.L.; funding acquisition, A.S. All authors have read and agreed to the published version of the manuscript.

**Funding:** The research was funded by the Russian Science Foundation, gran<sup>t</sup> number 18-19-00186.

**Acknowledgments:** RUSAL-Kamensk-Uralsky are acknowledged for providing materials. Technicians at Ural Branch of Russian Academy of Sciences are acknowledged for their assistance with XRD, XRF, EPMA, and ICP-MS analysis.

**Conflicts of Interest:** The authors declare no conflict of interest.
