Scientists from Far Eastern Federal University (FEFU), Ozersk Technological Institute, and the Russian Academy of Sciences have improved a processing technology of a monazite concentrate which is a mineral raw material employed as a source of rare earth elements and thorium. The latter, in turn, is a part of the thorium-uranium fuel cycle that is more eco-friendly compared to the one based on uranium and plutonium. A related article appears in Energies.
A team of scientists from FEFU and Ozersk Technological Institute (a branch of the National Research Nuclear University MEPhI) have optimized the technology of alkaline extraction of thorium from its main source, i.e. monazite concentrate stored at Uralmonazite State Enterprise (Krasnoufimsk, Sverdlovsk Region). The raw material contained 50% to 68% of REEs and 10% to 28% of thorium oxide.
The technology includes grinding and alkaline opening of the mineral raw material, turning target components into a solution, followed by extraction separation and purification of uranium, thorium, and REEs. The new method provided for the extraction of up to 90% of thorium and uranium and 100% of rare earth elements.
"Unlike uranium mineral products, the mineral commodities of thorium are found in abundance both in the Russian Federation and all over the world. A shift to the thorium-uranium cycle would secure the environmentally friendly development of the nuclear industry because this technology does not lead to the accumulation of nuclear waste. Moreover, as it claimed in scientific papers, with thorium-based fuel elements adoption, the nuclear core can be reduced by 2 to 3 times with no losses in the energy output. Also, according to this scenario, the reactor can be operated continuously for an estimated 50 years without fuel reloading", said Prof. Ivan Tananaev, the author of the work, and the Head of the School of Natural Sciences at FEFU.
According to the scientist, moving on to the thorium-uranium fuel cycle could become a medium-term matter in Russia due to the National nuclear energy development program which is considered a priority area for the modernization of the country's economy. Until recently, the nuclear industry in Russia has been working on the basis of the uranium-plutonium cycle that was developed in the middle of the XX century and guaranteed nuclear deterrence. As Prof. Tananaev believes, the utilization of an alternative thorium-uranium cycle has a number of indirect benefits. For example, the production of thorium leads to the development of the REE industry. Furthermore, secondary products of monazite processing are phosphate fertilizers that can be exploited in agro technologies.
###The work was carried out under the Cooperation Agreement between FEFU and the National Research Nuclear University MEPhI (dd. 24.11.2014), and supported by grant No. 18-29-24138 of the Russian Foundation for Basic Research, principal investigator is Prof. Ivan G. Tananaev, Head of the School of Natural Sciences at FEFU, Deputy Head of Research at OTI.