24 research outputs found
Perspective of Obtaining Rare Earth Elements in Poland
Along with the increasing development of electric and electronic industries, the demand for rare earth elements is also growing due to their high position in many applications. In Poland, there are minerals containing REE; however, the concentration of these elements in raw materials is rather low, so they do not have a big impact on the national economy. The potential source of REE is secondary materials; among them are phosphogypsum, uranium tailings, and the waste electrical and electronic equipment (WEEE). Lanthanides as accompanying metals of uranium in Polish uranium ores were leached in the technology of uranium recovery from these resources. The recovery of REE from pregnant liquors was conducted by solvent extraction and ion exchange. Novel apparatus solutions like membrane contactors in extraction stage were tested. Different types of matrices (uranium ore, phosphorites, etc.) were used
Uranium in Poland: Resources and Recovery from Low-Grade Ores
The presented studies deal with an assessment of the possibility of uranium recovery from the low-grade uranium resources in Poland. Uranium was leached from the ground uranium ores with efficiencies in 81–100% range that depend on the type of ore and leaching solution used. In the next step, the post-leaching solution was treated by the solvent extraction or ion exchange chromatography to separate uranium from other metals present in the ore. The novel routes of leaching by using membrane methods were examined. The final product, “yellow cake,” was obtained in precipitation step. The studies of precipitation of uranium as ammonium diuranate or uranium peroxide from diluted uranium solutions are presented in this chapter. The work was completed with tentative economic analysis and environmental impact assessment along with radiation protection issues connected to uranium production
Storage and Disposal Options for Nuclear Waste
Nuclear technology has multiple applications that are fundamental to our daily life [...
Pyrimidine-4-carboxylic acid
The crystal structure of the title compound, C5H4N2O2, is built of acid molecules located on a mirror plane. They form sheets stacked along the b-axis direction. The molecules interact via O—H...N hydrogen bonds, forming [001] chains, and weak van der Waals interactions
Uranium resources in EU phosphate rock imports
Most European countries import phosphate rocks for mineral phosphate fertilizer production. In 2017, approximately 5.5 million t phosphate rocks were imported into the EU-28 and subsequently processed. Phosphate rock can contain relevant amounts of accompanying uranium as well as rare earth elements that can be recovered during phosphate fertilizer production. Recovering uranium from phosphate rock is a proven process that has been used on an industrial scale in North America, Europe, and Asia in the 1980s until decreasing uranium prices in the 1990s made this practice uneconomic. In this work, we estimate the amount of uranium contained in EU phosphate rock imports in 2017 using publicly available data from Eurostat as well as average uranium concentrations found in the exporting countries and discuss potential recoverable quantities. Results of this estimate indicate that a maximum of 334 t natural uranium could have theoretically been recovered from 2017 EU phosphate rock imports. This amount of uranium could have supported approximately 2.1% of the EU nuclear power fleets 2016 natural uranium requirements and is of the same order of magnitude as domestic EU uranium production
Uranium resources in EU phosphate rock imports
Most European countries import phosphate rocks for mineral phosphate fertilizer production. In 2017, approximately 5.5 million t phosphate rocks were imported into the EU-28 and subsequently processed. Phosphate rock can contain relevant amounts of accompanying uranium as well as rare earth elements that can be recovered during phosphate fertilizer production. Recovering uranium from phosphate rock is a proven process that has been used on an industrial scale in North America, Europe, and Asia in the 1980s until decreasing uranium prices in the 1990s made this practice uneconomic. In this work, we estimate the amount of uranium contained in EU phosphate rock imports in 2017 using publicly available data from Eurostat as well as average uranium concentrations found in the exporting countries and discuss potential recoverable quantities. Results of this estimate indicate that a maximum of 334 t natural uranium could have theoretically been recovered from 2017 EU phosphate rock imports. This amount of uranium could have supported approximately 2.1% of the EU nuclear power fleets 2016 natural uranium requirements and is of the same order of magnitude as domestic EU uranium production
Management of Radioactive Waste Containing Graphite: Overview of Methods
Since the beginning of the nuclear industry, graphite has been widely used as a moderator and reflector of neutrons in nuclear power reactors. Some reactors are relatively old and have already been shut down. As a result, a large amount of irradiated graphite has been generated. Although several thousand papers in the International Nuclear Information Service (INIS) database have discussed the management of radioactive waste containing graphite, knowledge of this problem is not common. The aim of the paper is to present the current status of the methods used in different countries to manage graphite-containing radioactive waste. Attention has been paid to the methods of handling spent TRISO fuel after its discharge from high-temperature gas-cooled reactors (HTGR) reactors
Management of Radioactive Waste from HTGR Reactors including Spent TRISO Fuel—State of the Art
In light of the increasing demand for energy sources in the world and the need to meet climate goals set by countries, there is growing global interest in high temperature gas cooled reactors (HTGRs), especially as they are known to be inherently safe nuclear reactors. The safety of HTGRs results, among other, from the nature of the nuclear fuel used in them in the form of coated TRISO particles (tri-structural-isotropic) and the reduction of the total amount of radioactive waste generated. This paper reviews numerous methods used to ensure the sustainable, feasible management and long-term storage of HTGR nuclear waste for the protection of the environment and society. The types of waste generated in the HTGR cycle are presented as well as the methods of their characterization, which are important for long-time storage and final disposal. Two leading nuclear fuel cycle strategies, the once-through cycle (direct disposal or open cycle) and the twice-through cycle (recycling or partially closed cycle), are discussed also in relation to TRISO spent fuel. A short review of the possibilities of treatment of TRISO spent nuclear fuel from HTGR reactors is made