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Precipitation and Crystallization Processes in Reprocessing, Plutonium Separation, Purification, and Finishing, Chemical Recovery, and Waste Treatment
Published in Reid A. Peterson, Engineering Separations Unit Operations for Nuclear Processing, 2019
Calvin H. Delegard, Reid A. Peterson
Polonium (primarily of isotope 210) is present in aged uranium ore in concentrations proportional to the ratio of the polonium-210 and uranium-238 half-lives (t½ = 138 days and 4.47 × 109 years, respectively) or about one ten-billionth (8.5 × 10−11) of the concentration of uranium. The Curie and Curie (1898) separation of polonium (Po) from uranium ore extraction residues was effected by coprecipitation with native (to the ore) bismuth (Bi), first as a sulfide (with copper and lead), the dissolution of the bismuth sulfide to form a sulfate in sulfuric acid, coprecipitation with bismuth as a hydroxide, and finally by its fractional dissolution away from bismuth in dilute acid (Figure 4 in Adloff and MacCordick 1995). Experiments also showed that Po could be separated from ore residues, which also have Bi, by sublimation of the sulfides (Adloff and MacCordick 1995). The contact reduction of Po on less noble metals, including Bi, also effects some separation of a purer Po fraction (Bagnall 1957, 34). However, the exceedingly small concentration and correspondingly miniscule amounts of Po as well as polonium’s high specific activity make it difficult to achieve further purification, concentration, and thus chemical characterization by these techniques. Noteworthy is the fact that the technique and terminology of carrier precipitation was introduced by the Curies in their work to discover Po by their observations that the trace Po was chemically “carried” by the vastly more concentrated Bi as the sulfide and hydroxide.
Metals, Their Biological Functions and Harmful Impacts
Published in Karlheinz Spitz, John Trudinger, Mining and the Environment, 2019
Karlheinz Spitz, John Trudinger
Three different isotopes of polonium are included among the radon progeny. They are polonium218, polonium-214 and polonium-210. These pernicious substances are responsible for most of the biological damage attributed to radon. In particular, polonium-214 and polonium-218, when inhaled, deliver massive doses of alpha radiation to the lungs, causing fibrosis of the lungs as well as cancer. Animal studies have confirmed that polonium is extremely harmful, even in minute quantities.
P
Published in Splinter Robert, Illustrated Encyclopedia of Applied and Engineering Physics, 2017
[atomic, nuclear] Radioactive, unstable “metallic” chemical element, primarily found in uranium ores. Polonium was discovered by Marie (Manya) Sklodovska Curie (1867–1934) and her husband Pierre Curie (1859–1906) in 1898.
Manhattan Project: The Story of the Century, by Bruce Cameron Reed. Springer Nature Switzerland AG, 2020,
Published in Technometrics, 2022
Chapter 2 “From Atoms to Nuclei: An Inward Journey” traces the history of atomic and nuclear physics development from scientific research to new sources of energy and military applications. The chapter starts from German physicist W.C. Röntgen who in 1895 accidentally discovered X-rays—the mysterious rays passing through his hand and revealing a ghostly image of bones on a phosphorescent screen. French mineralogist A.H. Becquerel observed that samples of uranium ores left an image on photographic plates, that led him to the discovery of radioactivity in 1896. This radiation was produced by the so-called alpha and beta particles, known now as Helium-4 nuclei and electrons, emitted by nuclei of uranium or other heavy elements in the natural decay to more stable elements. Electrons were discovered in 1897 by English physicist J.J. Thomson who could determine the mass and electric charge. In 1900 French chemist P. Villard found gamma radiation which is the photon emission from nuclei and is of much higher energy than X-rays, and of million times greater energy than photons of visible light. Marie and Pierre Curie found two new elements called polonium and radium, coined a new term of radioactivity, and in 1903 they and Becquerel were awarded Nobel Prize. Nuclear research had been continued by E. Rutherford with his collaborators and students: F. Soddy on isotopes and a half-life decay from one radioactive element to another one; F. Aston on mass spectrometry; also, Geiger, Marsden, Chadwick—to mention just a few. The most famous of Rutherford’s discoveries was made in 1909-1911 on scattering and collision experiments which show that atoms have positively charged nuclei having the majority of the mass in atoms, with the much less massive electrons orbiting at far distances. If to scale them to a football field, a nucleus would be the size of a grain of rice. The term proton was coined by Rutherford in 1920, and he hypothesized about another, neutral, particle in nuclei, later called neutron. The laws of the total energy and electric charge conservation were established for nuclear reactions, but the mass can either be created or lost, in relation to transformation between mass and energy due to E mc2. If mass is lost (sum of the output masses is less than the sum of the input masses), it appears as kinetic energy of the output products; if mass is gained, then energy is drawn to create mass from the kinetic energy of the bombarding input nucleus. The mass gain or loss is measured in units of energy equivalent in mega electron-volt, or MeV. In 1919 Rutherford realized that the elements bombarded with some particles can be artificially transmuted into other ones, and the element 104 is named Rutherfordium in his honor.