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CHUKTUKON NIOBIUM-RARE EARTH METALS DEPOSIT: GEOLOGY AND
TECHNOLOGICAL CHARACTERISTICS OF THE ORES
S.S. Serdyuk and V.G. Lomayev
Geokomp Ltd, Krasnoyarsk, Russia
V.I. Kuzmin*, N.V. Gudkova, D.V. Kuzmin, M.A. Mulagaleeva, V.N. Kuzmina, and S.N. Kalyakin
Institute of Chemistry and Chemical Technology SB RAS, Krasnoyarsk, Russia
(*Corresponding author: [email protected])
O.A. Logutenko
Institute of Solid State Chemistry and Mechanochemistry SB RAS. Novosibirsk, Russia
ABSTRACT
The Chuktukon niobium-rare earth metal ore deposit is located in Siberia, in the Krasnoyarsk region. It is a
mineral raw materials resource which is capable, because of its qualitative and quantitative characteristics,
of providing a focus for the modernization of the rare metal industry of Russia. In this work, analysis of the
deposit structure and investigations on the choice of the potential processes for processing of the ores have
been carried out.
The ore deposit consists of weathered carbonatite rare metal crusts. The deposit itself is 3.5 km in length,
from 800 to 1400 m in width and up to 200 m in thickness. There are two ore types: a niobium-containing
ore (Nb2О5 cut off grade content is 0.8%) and a rare earth metal-containing ore (cut off grade REM content
is 3.0%). The mineral composition of these ores is goethite, hydrogoethite, hematite, psilomelane,
pyrolusite, barium pyrochlore, strontium pyrochlore, cerium pyrochlore, pyrochlore, florencite, monazite,
cerianite.
When processing the ores, it is possible to produce niobium, rare earth metals (REM), manganese,
vanadium, and iron. The REM ores reserves, as proved by the State Commission for Mineral Reserves of
Russia in 2007, are 6639 thousand tonnes (by category С2, accepted in Russia), niobium pentoxide – 39.8
thousand tonnes (0.6 % content), rare earth metal oxides – 486 thousand tonnes (7.3% content).
The ore is completely finely dispersed and consists of nanosized oxide particles formed of compact, dense
aggregates with an average particle size of 2 µm. Most of the REM, yttrium and thorium minerals are
located inside these particles which makes ore dressing as well as leaching of the rare and radioactive
elements to achieve a > 50% recovery very difficult. Pyrochlore is associated with the iron oxides to a
lesser extent.
Several options for processing of these ores have been considered:
1) reduction of the iron oxides to magnetite at 400-450°C, decomposition of the particles using
mechanical activation and isolation, by magnetic separation, of a rare metal concentrate as the
nonmagnetic fraction followed by hydrometallurgical processing;
2) alkaline-acid breakdown of the REM minerals, after a magnetizing, reducing roast of the ore,
resulting in recovery of the REM into solution, niobium recovery into the nonmagnetic concentrate by
magnetic separation of the cake resulting from hydrometallurgical processing;
3) decomposition of the ore particles and aggregates using mechanical activation and leaching of the
ore using nitric acid in an autoclave at 200°C resulting in the production of a phosphorus-free, low
iron content nitrate solution suitable for processing by solvent extraction.
KEYWORDS
Chuktukon niobium - rare earth deposit, geology, mineralogy, process options, magnetizing roast, alkalineacid breakdown, mechanical activation, nitric acid leaching