noun
definition
Naturally-occurring uranium oxide, a variety of the mineral uraninite.
Examples of pitchblende in a Sentence
To extract the metal, the pitchblende is first roasted in order to remove the arsenic and sulphur.
Pitchblende attained considerable notoriety towards the end of the 19th century on account of two important discoveries.
In 1789 Klaproth isolated from pitchblende a yellow oxide which he viewed as the oxide of a new metal, which he named uranium, after the newly discovered planet of Herschel.
Pure pitchblende is U308, which, in relatively good specimens, forms some 80% or more of the whole.
After the discovery of the radioactive properties of uranium by Henri Becquerel in 1896, it was noticed that some minerals of uranium, such as pitchblende, were more active than the element itself, and this circumstance suggested that such minerals contained small quantities of some unknown substance or substances possessing radioactive properties in a very high degree.
Petroleum has been found near Torres Vedras; pitchblende, arsenic, anthracite and zinc are also mined.
Marckwald (Ber., 1903, 36, p. 2662) showed that the Joachimsthal pitchblende yields tellurium and a minute quantity of the strongly radioactive polonium which is precipitated by bismuth (see Radioactivity).
The only practically available raw material for 'the extraction of uranium is pitchblende (q.v.).
It is manufactured by heating pitchblende with lime, treating the resulting calcium uranate with dilute sulphuric acid, and adding sodium carbonate in excess.