Author:
Jan Scholten
Book:
Secret Lanthanides
Type:
Physical
Chapter:
5.0
5.0 Praseodymium physical
Praseodymium is soft, silvery, malleable, and ductile. It was prepared in relatively pure form in 1931. It is somewhat more resistant to corrosion in air than europium, lanthanum, cerium, or neodymium, but it does develop a green oxide coating that 'spalls' away when exposed to air. The metal should be stored under an inert atmosphere or under mineral oil or petroleum.
The rare-earth oxides, including Pr2O3, are among the most refractory substances known. It is a component of mischmetal, used for lighter flints, and of the glass in welders’ goggles.
Atomic number: 59.
Symbol: Pr.
Discovery: 1885, Austria, Carl F. Auer von Welsbach.
Name: Greek for green (praseos) twin (dydimos).
Originally it wasn’t split from neodymium and together they were known as the “element” Dydimos, twins.
Toxicology: mild.
Ore: monazite and bastnasite, 5% of mischmetal.
Uses
1. Carbon arc lights used by the motion picture industry
2. Salts used to color glasses and enamels; when mixed with certain other materials, praseodymium produces an intense clean yellow color in glass. Component of didymium glass which is a colorant for welder’s goggles
3. Metal, used in making cigarette lighters, contains about 5% praseodymium metal
4. Alloys
5. Green salts.
6. Coloring glass and ceramics yellow.
7. Yellow filtering glass and lenses.
10. Cigarette lighter.
11. Pr2O3 is very refractory.
12. PrNi5 is used in cooling to very low degrees, 1 in 27 million of a degree above zero Kelvin.
13. PrFeB is used as strong magnets at very low temperatures.
14. Alloy with magnesium to create high-strength metals for aircraft engines.
15. Didymium glass, which is used to make certain types of welder’s and glass blower’s goggles.