Uranium is a trace element in the earth’s crust. Because of its low content and uneven distribution, the abundance of uranium in the earth’s crust varies greatly. The general value is on the order of parts per million (10−6), while the highest value can reach 10−4. Although it may seem that the content of uranium is minor, In fact, it is higher than that of tungsten, mercury, silver, and other familiar metals, being even thousands of times higher than that of gold!

Geological exploration of Mongolia has been extremely inconsistent. From the frst regional exploration by Russian explorers of Asia to the present, little more than 41% of the country’s territory has been covered by areal geological surveys in combination with prospecting at a scale of 1:50,000. Regional geological surveys at a scale of 1:200,000, 1:500,000, and 1:1,000,000 cover 100% of the country.

Настоящее положение разработано Всесоюзным геологоразведочным объединением ("Союзгеологоразведка") Министерства геологии СССР во исполнение постановления Совета Министров СССР от 25 сентября 1981 года № 944-282. Положением учтен многолетний опыт проведения массовых поисков в стране, достижения научно-технического прогресса в геологии и требования новой системы планирования и организации геологоразведочных работ. Введение нового положения будет способствовать дальнейшему развитию и совершенствованию массовых поисков месторождений урана, улучшению их организации и повышению эффективности.

Significant uranium deposits and mining were restricted to eastern Germany (until 1990 German Democratic Republic/GDR) while only few small uranium deposits have been mined in western Germany.

The emphasis of this volume is on the characterization of uranium deposits. Chapter 1 includes an introductory note in the form of a brief summary of world uranium resources and their definitions with respect to confidence classes and cost categories. This was considered justified insofar as an understanding of an ore deposit cannot be achieved from purely geological parameters. Economic considerations have to be included. Demand for the commodity and, in the western world, related price/cost factors dictate and define whether a localized metal concentration is a deposit that can be profitably exploited presently or in the future, or whether it is a mineral occurrence of only scientific value.

A variety of global and regional classifi cation schemes for uranium deposits have been proposed in the past by a number of geoscientists including Heinrich (1958), Roubault (1958), Ruzicka (1971), Ziegler (1974), Mickle and Mathews (1978), Mathews et al. (1979), Nash et al. (1981), Barthel et al. (1986), Dahlkamp (1989, 1993), McKay and Miezitis (2001) mainly for deposits in the western hemisphere and by Kazansky and Laverov (1977), Boitsov (1989, 1996),

Геохимические методы поисков месторождений полезных ископаемых, теоретические основы которых были заложены в России, прочно вошли в практику геологопоисковых и геологоразведочных работ как в России, так и во всем мире. Высокая геологическая эффективность этих методов доказана многочисленными открытиями месторождений цветных, редких и благородных металлов.

The uranium minerals that today are at the centre of worldwide attention were unknown until 1780, when Wagsfort found a pitchblende sample in 10hanngeorgenstadt. This discovery passed unnoticed, however, since Wags fort thought that it contained a black species of a zinc mineral-hence the n':lme 'pitchblende' (= pitch-like blende). Seven years later, Klaproth, while examining the mineral, noted that it contained an oxide of an unknown metal, which he called 'uranium' in honour of the planet Uranus, recently discovered by Herschel. Klaproth also believed that he had separated the metal, but, in fact, the attempt failed, and uranium, given its strong affinity with oxygen, was not separated until several years later. In 1833 Arfwedson attempted the separation and, in so doing, reduced the pitchblende. His attempt was not successful and only U02 was obtained. It was Peligot, in 1840, who was finally successful. He managed the reduction of the metal working with metallic potassium. It should be remembered that twelve years earlier Berzelius had isolated thorium.

In 1983 the Nuclear Energy Agency of the Organisation for Economic Cooperation and Development (OECD/NEA) and the IAEA jointly published a book on Uranium Extraction Technology. A primary objective of this report was to document the significant technological developments that took place during the 1970s. The purpose of this present publication is to update and expand the original book.