The Dobrovolnoye uranium mine is an underground deposit being developed as a pilot production project in the Kurgan region of Russia. Rosatom’s mining division joint-stock company ARMZ Uranium Holding and its subsidiary Dalur are responsible for the development of the deposit.
The mining project involves the development of a pilot in-situ leaching (ISL) site for underground uranium leaching operations.
Recommended White Papers
The Government of the Russian Federation awarded a permit for exploration and development of the uranium deposit to Dalur in May 2017.
The licence provided the rights to make use of the subsoil plot of federal significance for uranium exploration and extraction. Drilling operations on the deposit commenced in 2018 to assess the boundaries of the ore body and the uranium content.
Construction activities on the Dobrovolnoye pilot plant commenced in November 2021 and the start of uranium production is scheduled for December 2022.
The commissioning of the pilot plant is expected to allow Dalur to increase its uranium production capacity to 700 tonnes of uranium per year by 2025.
Location, geology and mineralisation
The Dobrovolnoye uranium mine is located in the Uksyanskoye village, Zverinogolovsky district in the Kurgan region of Russia.
The project site lies in the catchment area of the Tobol River situated in the Trans-Urals uranium ore district.
The deposit is a paleovalley type deposit appearing as a rock from the below and sides, and about 100m impenetrable clay from the above. The orebodies occur in the form of a ribbon, 1km to 7km long, 50m to 700m wide with a thickness of 1.5m to 11m.
The uranium minerals in ores are represented by coliform uranium oxides and coffinite. It is also accompanied by marcasite, pyrite, jordisite, sphalerite, chalcopyrite, ferriselite, natural selenium, and rhenium oxides.
Dobrovolnoye is a varved deposit with uranium mineralisation stretching over a total length of approximately 18km. The deposit is almost similar in size to that of the Dalmatovskoye deposit, which is being developed since 1984 and entered into commercial operations in 2002.
Estimated reserves
The Dobrovolnoye uranium deposit is estimated to hold approximately 7,077 tonnes (t) of uranium at a grade value ranging from 0.01% to 0.05% uranium (U).
Drilling operations
The mineral exploration operations at the Dobrovolnoye uranium deposit were completed in October 2020. It involved drilling of a total 218 exploratory wells (drilling up to 117,093 linear metres) for the extraction of overlying source rocks.
The drilling operations were facilitated by the application of new generation equipment for direct determination of uranium in wells, KND-M instrumental and methodical complex. The complex method delivered an ability to simultaneously record the uranium content and the filtration characteristics of ores and ore-bearing blocks.
Well drilling activities also involved the application of a drilling fluid based on bentonite clay in the sinking wellbore process.
Mining method and ore processing
The Dobrovolnoye uranium mine will employ a sulphuric acid ISL mining method for the extraction of uranium.
The process involves pumping complexing reagents solution and an oxidising component into the wells drilled to the deposit. The leaching solution oxidises and dissolves only the uranium minerals without dissolving the uranium ores.
The application of the underground leaching method facilitates releasing of the metal from the ore-bearing layer and raising it to the top driven through a special ion-exchange resin. While the uranium is extracted from the resin, the resin is reused as a waste-free and environment-friendly component.
Infrastructure facilities
The infrastructure facilities at the Dobrovolnoye uranium deposit involve the construction of an ISL pilot site, administrative and amenity building, a compressor house, a sodium nitrite storage facility, warehouses, an operations control centre on a 150m² area, a mud pit and access road.
Contractors involved
RUSBURMASH, a specialised company within ARMZ Uranium Holding, was selected to carry out the mineral exploration work at the Dobrovolnoye uranium deposit in November 2019. The scope included the drilling of wells, geophysical surveys, hydrogeological and engineering-geological works, and analytical studies.
The company was also contracted for the erection of buildings and facilities along with the interior works on the pilot in-situ leaching site.
