When the topic of rare earths is opened, Lanthanide, a member of the elemental table and one of the largest families of rare earths, is absolutely indispensable.
Most of the Lanthanide elements are found in both monazite and diabase minerals, and they tend to be mixed together in fairly constant proportions (25%-38% of them are Lanthanum), which are separated as oxides, and they are both derived from rare minerals, classified as ”rare earths” along with the elements Scandium and Yttrium, but the elements themselves aren’t really that rare.
The Lanthanide Family.
The similarity of the properties of the Lanthanide elements is attributed to the fact that the electron configuration of the outer and the second outer layers of the atomic ground state of the Lanthanide elements are essentially the same. Most of the newly added electrons are filled into the 4f layer, which is the third electron layer counted from the outside, and this gives rise to the phenomenon of “Lanthanide contraction”, in which the radius of an atom becomes smaller as the atomic number increases. With this phenomenon, the atomic radii of the Lanthanide elements are different from the ionic radii, resulting in a tendency for the physical and chemical properties of the Lanthanide elements to differ, which facilitates the separation of the Lanthanide elements. Probably the most important use of Lanthanide compounds is in the manufacture of electrodes for carbon arc bulbs in searchlights, photographic lamps, and animation projectors.
As mentioned above, the properties of the Lanthanide elements are very similar, so you should be able to recognize one of the other members of the Lanthanide family! Let’s start with the first element of Lanthanide, “Lanthanum”!
Lanthanum derives its name from the Greek word “lanthanein”, meaning “hidden”. It was discovered in 1839 by the Swedish chemist Carl Gustaf Mosander, who extracted it as an impurity from the rare earth element mineral cerium nitrate. It was not until 1923 that the purer metal, Lanthanum, was isolated; it is a white metal, reactive, malleable and soft enough to be cut with a knife. It oxidizes quickly in air and reacts strongly in hot water, emitting hydrogen. lanthanum is found mainly in monazite sand, which contains all the rare earth elements, as well as calcium and thorium, usually in the form of phosphates, and in the fission fragments produced by the fission of ureum, along with its isotopes. During the fission process, Uranium absorbs a neutron and the Uranium nucleus splits into two medium-sized fragments. Because of the many ways of splitting, a large number of elements with medium-sized nuclei are formed, including isotopes of Lanthanum.
Lanthanum’s application:
Lanthanum oxide improves the alkali resistance of glass and has been used to produce specialty glasses for complex optical instruments.
As an alloy, Lanthanum has the same ”hydrogen sponge” capability as Palladium, i.e., it has a high density that can absorb gases.
Lanthanum neutralizes phosphorus, so it is often used in ponds to prevent unwanted growth of algae.
Lanthanum carbonate is approved as a drug for the absorption of excess phosphate in cases of hyperphosphatemia in kidney failure.
The flint used in lighters is a ”mixed rare earth” alloy containing Lanthanum (25% Lanthanum, 50% Cerium, 18% Neodymium, and other perylene elements).
