Rhenium: Radionuclides

Abstract

The occurrence, chemistry, and speciation of rhenium (Re) in environmental components such as soil and water, as well as rhenium separation and analytical characterization techniques in the environment, are summarized. Rhenium has two isotopes: one is stable 185 Re and the other is radioactive 187 Re, which has a very long half‐life of 4.35 × 10 10 years. The decay system, 187 Re– 187 Os has been used for dating rocks and meteorites. Artificially made radioisotopes with short half‐lives, such as 186 Re and 188 Re have been used in radiopharmaceuticals. Because of similarities in chemistry, rhenium has been used as a chemical analog of technetium.

Plants to harvest rhenium: scientific and economic viability

“…However, note that the results of the Indian mustard were two orders of magnitude above those of scouring rush. In addition, the harvestable amount of the Indian mustard increased significantly from 45 to 75 days Environ Chem Lett 2014b), a 98 % efficiency on the Re extraction process from plant mass (Bozhkov et al 2012), a moderate plant density (50 plant m -2 ) (Liu et al 2012), the energy production income from biomass incineration (215 US$ tonne -1 ) (Harris et al 2009), the typical agricultural costs (1000 US$ ha -1 , including fertilizers, irrigation, and seed costs) (Sheoran et al 2013), and a projected cost of 1000 US$ ha -1 for the extraction and purification process (Abisheva and Zagorodnyaya 2002;Harris et al 2009;Tagami and Uchida 2010;Bozhkov et al 2012;WilsonCorral et al 2012), then a profit of 3906 US$ ha -1 harvest -1 would be expected from the recovered Re. In the light of this result, the profitability of Re phytomining could be used to finance the phytoremediation of soils with coexisting and often toxic metals (As, Cd, Cr, Cu, Mn, Pb, Se, and Zn) (Stankovic et al 2014) that can be concurrently removed by the Indian mustard (Vamerali et al 2009) and promote carbon dioxide abatement (Witters et al 2012;Yang et al 2012).…”

“…Conventionally, MoS 2 concentrates are roasted between 500 and 700°C to obtain molybdenum trioxide (MoO 3 ), while volatile rhenium heptoxide (Re 2 O 7 ) is released with the flue gases. Re 2 O 7 is then scattered on the soil, where in the presence of water it is promptly transformed to perrhenate (ReO À 4 ), the most stable form of Re (Askari Zamani et al 2005;Tagami and Uchida 2010). Bioleaching of MoS 2 concentrates is, to a lesser extent, another pathway to the generation of ReO À 4 (Askari Zamani et al 2005).…”

“…Due to its scarcity, Re was not discovered until 1925, making it the last stable element to be detected (Tagami and Uchida 2010). Because of its distinctive physicochemical properties, Re is also one of the most expensive metals in the world market (Naumov 2007;Polyak 2014a).…”

“…Soils and natural waters usually present low Re concentrations. Anthropogenic sources of Re include motorways, coalburning plants, non-ferrous metals smelters, scrap recycling units, copper processing factories, and specially, copper-molybdenum mines (Tagami and Uchida 2010;Bozhkov et al 2012;Polyak 2014a;Zakrzewska-Koltuniewicz et al 2014). Molybdenite (MoS 2 ), a by-product in copper mining, is the main host of Re, typically as rhenium disulphide (ReS 2 ).…”

“…Rhenium is one of the rarest elements on Earth, with an abundance fivefold lower than gold and an estimate concentration of 0.4-0.6 lg kg -1 in the upper crust (Tagami and Uchida 2010;Kabata-Pendias 2011). Due to its scarcity, Re was not discovered until 1925, making it the last stable element to be detected (Tagami and Uchida 2010).…”