Uranium geochemistry, mineralogy, geology, exploration and resources Uranium geochemistry, mineralogy, geology, exploration and resources Edited by B. De Vivo, F. Ippolito, G. Capaldi and P. R. Simpson The Institution of Mining and Metallurgy © The Institution of Mining and Metallurgy 1984 Softcover reprint of the hardcover 1st edition 1984 ISBN-13: 978-94-009-6062-6 e-ISBN-13: 978-94-009-6060-2 001: 10.1007/978-94-009-6060-2 UDC 550.4:553.495.2 Published at the offices of the Institution of Mining and Metallurgy 44 Portland Place London WI England Introduction Since then the uranium market has been subject to two other turning points that, in the course of a few years, have made this The uranium minerals that today are at the centre of worldwide metal an essential raw material. attention were unknown until 1780, when Wagsfort found a First, the destructive property of fission reactions made pitchblende sample in 10hanngeorgenstadt. This discovery uranium a metal of fundamental strategic importance, increas­ passed unnoticed, however, since Wags fort thought that it ing research in some nations, but the revolution came with the contained a black species of a zinc mineral-hence the n':lme plan for the real possibility of utilizing chain reactions for 'pitchblende' (= pitch-like blende). Seven years later, Klaproth, energy production in place of conventional fuels. while examining the mineral, noted that it contained an oxide Since that time a 'uranium race' has been in progress in many of an unknown metal, which he called 'uranium' in honour of countries-often justified by the well-founded hope of the planet Uranus, recently discovered by Herschel. Klaproth becoming self-sufficient with regard to energy, or at least of also believed that he had separated the metal, but, in fact, the paying off a part of the financial deficit due to increasing fuel attempt failed, and uranium, given its strong affinity with imports. oxygen, was not separated until several years later. In 1833 The importance of electro-nuclear energy should, however, Arfwedson attempted the separation and, in so doing, reduced be considered on the world rather than the national scale, the pitchblende. His attempt was not successful and only U02 especially when the following points are taken into account: the was obtained. It was Peligot, in 1840, who was finally success­ very marked increase in the demand for energy, the increasing ful. He managed the reduction of the metal working with cost of classic fuels and the need to use the latter more and more metallic potassium. It should be remembered that twelve years for specialized purposes (chemical, iron and steel industries, earlier Berzelius had isolated thorium. motor-vehicle traction, etc.). This successful outcome of the experiment, however, was not Thus, exploiting radioactive material is a very urgent given much importance in uranium history because, initially, national and world problem and the many aspects of the geo­ there was little interest among scientists in this metal and in the chemistry and geology of uranium and thorium ore deposits are industrial-technical field the many attempts to use it in the form of extreme value in both theoretical and practical terms. of metal had scarcely proved successful. Attempts were made With these points in mind, in 1960 one of the editors (F.L) to use it for making Auer mantles in gas-lighting; filaments in presented Lezioni di Geologia dell'Uranio (lessons on the electric light-bulbs were also tried, but both experiments failed. geology of uranium), which summarized a course held for a Only U 30g, some uranates and some uranium salts were utilized decade at the School of specialization in applied nuclear physics as dyes in ceramics and in the glass industry, and also for special at Milan Polytechnic. Owing to the novelty of the subject and photographic preparations. As a result of such a limited utiliz­ the particular interest that it holds for the development of the ation, the demand for uranium remained so low that, at the end nuclear industry, these lessons quickly became obsolete, and it of the last century, the only mineral deposit to be exploited was was felt that a new publication was necessary for both students that in 10achimsthal, Bohemia-the same formation in which, and practising exploration geologists. Because of the com­ in 1780, Wagsfort had found the first pitchblende sample. The plexity of the subject, which, if it is to be treated thoroughly, other known mineral deposits at that time-those in Portugal, should be considered as an interdisciplinary field of research, Cornwall, Colorado, etc.-were practically untouched. Even with the help of our co-editors we decided to promote this thorium found no practical application until 1885, when Auer volume in which. various specialists treat the problems that are used the oxide for constructing the mantles that had been presented by the geology of uranium in the widest sense. We patented by him. hope that the presentation of these complex problems-from The year 1895 marks the beginning of a new chapter in the the mineralogy of uranium to the ~earch for it and its practical history of uranium minerals. Becquerel discovered the radio­ utilization-from different aspects and as completely as active property of pitchblende and the Curies isolated radium. possible has been successful. Suddenly scientists everywhere became interested in uranium We wish to thank all our collaborators and the Institution of minerals, which assumed a new importance in the mining Mining and Metallurgy, which has assumed responsibility for industry. The extraction of radium from uranium salts led to publishing this volume. the development of significant mining exploitation at St. Ives in Cornwall, in the Paradox Valley in Colorado and in Portugal. Benedetto De Vivo The first discoveries of uranium minerals in Katanga go back Felice Ippolito to 1915 and in 1921 exploitation was begun. The wealth of these January, 1984 mines was such as to put into difficulty all the others, including the loachimsthal deposits. v Contents Introduction Uranium exploration Benedetto De Vivo and Felice Ippolito v Richard H. De Voto 101 History of radioactivity Geochemistry of uranium in the hydrographic network Paolo Gasparini Bernard Soyer 109 Uranium in mantle processes Uranium deposits of the world, excluding Europe Massimo Cortini 4 Robert G. Young 117 Transport and deposition of uranium in hydrothermal systems Uranium deposits in Europe at temperatures up to 300°C: geological implications Valery Ziegler and Jacques Dardel 140 Samuel B. Romberger 12 Uranium in the economics of energy Geochemical behaviour of uranium in the supergene environ­ B. De Vivo and F. Ippolito 162 ment Gaetano Dongarra 18 Role of high heat production granites in uranium province formation Uranium exploration techniques P. R. Simpson and Jane A. Plant 167 Chester E. Nichols 23 Uranium deposits in Italy Uranium mineralogy Claudio Tedesco 179 Deane K. Smith Jr. 43 Name index 189 Time, crustal evolution and generation of uranium deposits R. W. Hutchinson and J. D. Blackwell 89 Subject index 194 vii by uranium. The radiations from thorium proved more diffi­ History of radioactivity cult to deal with because the ionization seemed to fluctuate widely. Owens proposed air current as the possible cause of the problem and, just before leaving for England for his summer vacation, succeeded in stabilizing the ionization by sealing his thorium oxide specimen in an airtight box. Rutherford was left Paolo Gasparini alone to explain the puzzle, rapidly reaching the conclusion that Istituto di Geologia e Geofisica, University of Naples, Italy the fluctuations in ionization were due to the 'emanation' of a radioactive substance from thorium. One year later, in Our understanding of the evolution of the earth and the solar London, Sir William Crookes was trying to purify uranium system had its beginning in radioactivity. Radioactivity pro­ nitrate. In doing so he was astonished to discover that he had vided a tool for absolute geochronology, it was found to be an almost completely eliminated the radioactivity from uranium. important heat source within the planets and it produced small He began a series of chemical tests that separated uranium from changes in the isotopic composition of some elements, which a totally different, highly radioactive substance, which he enabled us to trace geochemical processes back to the earth's called 'Uranium X'. Additionally, a new emanation was dis­ past. Moreover, radioactive processes are a source of energy for covered from radium. human beings. Rutherford realized that any further progress would be diffi­ The history of radioactivity as a science is full of surprises cult without the help of a chemist and persuaded Frederick and the outstanding quality of those prominent in this field was Soddy to join him in his work. He and Soddy proposed to (I) a mind that was open to the unexpected rather than possessing ascertain whether the emanation came from thorium or from the capability of foresight and research planning. something that was also mixed with it, (2) discover what kind In 1896, shortly after Rontgen had shocked the scientific of gas the emanation might be, (3) weigh the emanation and world by announcing the discovery of X-rays, Henri Becquerel, (4) ascertain what chemical properties of thorium made the stimulated by Rontgen's results, hoped to produce X-rays from emanation possible. They found definite answers to the first fluorescent minerals. Becquerel had the idea, perfectly plaus­ two questions: the emanation came from a highly radioactive ible at that time, that X-ray emission and fluorescence had the substance, which they called 'Thorium X', and the emanation same cause. The concept later proved to be completely false, had the chemical behaviour of an inert gas of the argon series.