Processing of mill tailings as a source of rare earth elements in the development of Russian man-made deposits

L.G. Rudenko, N.N. Gubskaya, E.P. Petukhova, A.V. Ovsyannikova, E.M. Torbik
Financial University under the Government of the Russian Federation, Moscow, Russian Federation
Russian Mining Industry №3/ 2026 p. 62-70

Abstract: This paper examines the issue of extracting the rare earth elements (REEs) from tailings of Russian mining and processing plants, which are recognized as promising man-made deposits. This research is relevant due to Russia's critical dependence on imported separated REE oxides (up to 75% of the domestic consumption, with 28.5 million tons of the balance reserves) and the growing environmental pressure from the tailings dams, which have accumulated over 8 billion tons of mining waste. The study's hypothesis is that a combined process flowsheet, including physical pre-concentration followed by selective hydrometallurgical leaching, ensures economically viable extraction of REEs from tailings with the ΣTR2O3 content of at least 0.25%. The objective of this study is to conduct a feasibility study for processing mill tailings as an alternative source of the rare earth elements (REE) as part of the import substitution program up to 2030. The methods of comparative geochemical analysis, scenario-based technical and economic modeling (NPV, IRR, DPP), and a laboratory study of the extraction efficiency using the ICP-MS, X-ray fluorescence, and SEM-EDS data were applied. The empirical base included geochemical characteristics of tailings from seven of the largest man-made tailings in the Russian Federation (the Khibiny Processing Plants, the Lovozero Mining and Processing Plant, the Kachkanarsky Mining and Processing Plant, the Mundybash Processing Plant, the Solnechny Mining and Processing Plant, phosphogypsum dumps, and the PhosAgro tailings), as well as data from the state reserve balance (2022–2025). The total REE resource potential of the tailing dumps was estimated at 3.8–4.6 million t of ΣTR2O3, with the combined technology providing a recovery of 78–88% of the REEs with the concentrate purity of 92–96%. Technical and economic modeling demonstrates a positive NPV of RUB 6.94 billion under the baseline scenario (0.35% grade, r = 12%), an IRR of 19.2%, and a payback period of 5.8 years. The environmental benefit of processing 500,000 t of tailings per year results in a reduction in the CO2-equivalent emissions of 18.7 thousand t/year. The results confirm the industrial value of man-made deposits as a strategic resource for ensuring the country's technological sovereignty in the field of critical minerals

Keywords: rare earth elements, mill tailings, man-made deposits, hydrometallurgical leaching, pre-concentration, feasibility study, circular economy

For citation: Rudenko L.G., Gubskaya N.N., Petukhova E.P., Ovsyannikova A.V., Torbik E.M. Processing of mill tailings as a source of rare earth elements in the development of Russian man-made deposits. Russian Mining Industry. 2026;(3):62–70. (In Russ.) https://doi.org/10.30686/1609-9192-2026-3-62-70

Article info

Received: 10.02.2026

Revised: 24.03.2026

Accepted: 02.04.2026

Information about the authors

Lyudmila G. Rudenko – Dr. Sci. (Econ.), Professor at the Department of Economic Theory, Financial University under the Government of the Russian Federation, Moscow, Russian Federation; https://orcid.org/0000-0001-7059-0198; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Natalya N. Gubskaya – Cand. Sci. (Econ.), Associate Professor at the Department of Strategic and Innovative Development, Financial University under the Government of the Russian Federation, Moscow, Russian Federation; https://orcid.org/0009-0009-8987-7928; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Ekaterina P. Petukhova – Cand. Sci. (Econ.), Associate Professor at the Department of Industrial Markets, Financial University under the Government of the Russian Federation, Moscow, Russian Federation; https://orcid.org/0000-0002-9298-7468; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Anna V. Ovsyannikova – Cand. Sci. (Educ.), Associate Professor at the Department of Mathematics and Data Analysis, Financial University under the Government of the Russian Federation, Moscow, Russian Federation; https://orcid.org/0000-0002-1716-3100; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Elena M. Torbik – Cand. Sci. (Philol.), Associate Professor at the Department of English Language and Professional Communication, Financial University under the Government of the Russian Federation, Moscow, Russian Federation; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

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