Promethium is not normally extracted from pitchblende as it has only been found in this mineral very rarely. Pitchblende is another name for the mineral uraninite which contains uranium oxide, lead, thorium, and rare earth elements. As promethium is a lanthanide, it is possible to isolate it from pitchblende using similar processes that are used to separate lanthanides from the minerals they occur in. The process would have to involve treatment of the uraninite with sulphuric acid, hydrochloric acid, and sodium hydroxide to extract the lanthanides in their salt form. Further processing using solvent extractions and ion exchange chromatography would isolate promethium as a fluoride form. A heated reaction with calcium would yield pure promethium.
Pure promethium is normally collected as a by production from uranium fission. The process of uranium fission involves slitting the uranium atom to form ‘fission.’ Pure promethium must be handled with extreme caution as it has strong radioactive characteristics.