Neodymium Element Properties and Information
Neodymium Element Properties and Information
Neodymium is 60th element on the periodic table. Elements are arranged in the periodic table on the basis of the atomic number. Atomic number is the number of protons in the nucleus of the atom. Neodymium has an atomic number of 60. It is located in the Group ‘Lanthanides’ and Period 6 of the periodic table of elements. It is denoted by ‘Nd’. The name is derived from the Greek ‘Neos Didymos’ which means ‘New Twin’.
Carl Mosander announced in 1841 that he discovered a new element called didymium. It was accepted as an element for 40 years. Some chemists had suspicion that didymium is a mixture of elements. Spectroscopic studies showed that didymium was not a pure element. Carl Auer Von Welsbach successfully split didymium into its two components; neodymium and praseodymium in 1885 but he obtained them in the form of oxides. A pure sample of neodymium metal itself was produced in 1925.
Neodymium occurs with other lanthanides in variety of minerals. Its main sources are bastnaesite and monazite.
Physical Properties
- Neodymium is a hard, somewhat malleable metal which is silvery-white in appearance. It is the 4th lanthanide in the lanthanide series.
- The atomic mass of neodymium is 144.2.
- The melting point of neodymium is 1024°C.
- The boiling point of neodymium is 3074°C.
- The density of neodymium is 7000 in S.I. units at 20°C.
- Below 863°C, neodymium exists in a double hexagonal form. Above 863°C, neodymium exists in a body-centered-cubic structure.
- Neodymium is paramagnetic at room temperature. It becomes ferromagnetic if it is cooled to 20K.
- Neodymium consists of 5 naturally occurring stable isotopes; neodymium-142, neodymium-143, neodymium-145, neodymium-146, and neodymium-148.
Chemical Properties
- Neodymium metal tarnishes quickly in the presence of air and moisture.
- Neodymium metal has the potential to get oxidized quickly. The compounds formed exist in +2, +3, and +4 oxidation states which are pink, purple/blue, and yellow in colour respectively.
- Neodymium burns readily at 150°C forming neodymium(III) oxide. The oxide layer peels off on its own thus exposing further layer for oxidation.
- Neodymium reacts with water; it reacts slowly with cold water and faster with hot water. Thus, rate of reaction increases with increasing temperature of water.
- Neodymium metal reacts with all halogens vigorously to form trihalides.
Methods of Production
- From Bastnaesite: Bastnaesite lacks thorium and heavy lanthanides and further purification from light lanthanides is also less involved. The ore is first grounded and crushed and then it is treated with hot-concentrated sulphuric acid resulting in formation of water-soluble sulfates of lanthanides. After the gases evolve and escape from the system, the solution is leached and dried. Leaching and ion-exchange step then separates neodymium from other lanthanides.
- From Monazite: The ore is first subjected to electrostatic separation multiple times to separate its magnetic properties. After separation it is treated with hot-concentrated sulphuric acid to get dissolved sulfates of lanthanides. The acid filter is neutralized using sodium hydroxide at pH 3-4, during this process; the thorium gets removed as a hydroxide. The solution is then treated with ammonium oxalates to get lanthanide oxalates. The oxalates are converted to oxides by annealing. The oxides are then dissolved in nitric acid solution wherein cerium gets removed because of its insolubility. The neodymium is at last separated from other lanthanides using ion-exchange chromatography.
Relevance in Chemical and Related Industries
- Glass Industry: Addition of neodymium oxide in glass melts produces neodymium glass. These glasses appear lavender in day light or incandescent light and appear pale blue under fluorescent light.
- Fertilizers: Rare-earth-element compounds are used in some fertilizers. The rare-earth-element-ions promote plant growth.
Relevance in Other Industries
- Cryocoolers: Neodymium is used in cryocoolers because it has large specific heat capacities at liquid-helium temperatures.
- Ore dating: Samarium-neodymium can be used for determining the age of ores and rocks.
- Magnets: Neodymium magnets are the strongest magnets known to mankind. A few grams of neodymium magnet can lift a thousand times its own weight.
- Lasers: Neodymium doped transparent materials can be used as an active laser medium for infrared region. Certain examples are; Nd:YAG, Nd;YLF, Nd:Glass, etc.
- Oceanography: Neodymium isotopes recorded in marine sediments are used to reconstruct changes in past ocean circulation.
Health Effects on Exposure
- Dusts: Neodymium dusts are very irritating to the eyes.
- Ingestion: Neodymium salts which are insoluble are regarded as non-toxic. Neodymium salts which are soluble are slightly-toxic. If they accumulate in liver then they pose threat to its proper and optimal working condition.
- Inhalation: Neodymium based gases can be inhaled in rare-earth element based working environments. On long exposure, lung embolism can occur.
Effects on Surroundings
- Soil: Due to dumping of wastes, especially from petroleum industries, the concentration of neodymium in soil is gradually increasing.
- Water animals: The exposure destroys their cell membranes.
References:
https://en.wikipedia.org/wiki/Neodymium
https://www.lenntech.com/periodic/elements/nd.htm
