Lanthanum, element 57 of the periodic table.
In order to make the periodic table of elements look more harmonious, people took out 15 kinds of elements, including lanthanum, whose Atomic number increases in turn, and put them separately under the periodic table. Their chemical properties are similar. They share the third lattice in the sixth row of the periodic table, which is collectively referred to as "Lanthanide" and belongs to "rare earth elements". As the name suggests, the content of lanthanum in the earth's crust is very low, second only to cerium.
At the end of 1838, Swedish chemist Mossander referred to the new oxide as lanthanide earth and the element as lanthanum. Although the conclusion has been recognized by many scientists, Mossander still has doubts about his published results because he saw different colors in the experiment: sometimes lanthanum appears in red purple, sometimes in white, and occasionally in pink as a third substance. These phenomena made him believe that lanthanum may be a mixture like cerium.
Lanthanum metal is a silver white soft metal that can be forged, stretched, cut with a knife, slowly corrodes in cold water, reacts violently in hot water, and can emit hydrogen gas. It can directly react with many non-metallic elements such as carbon, nitrogen, boron, selenium, etc.
A white amorphous powder and nonmagnetic Lanthanum oxide is widely used in industrial production. People use lanthanum instead of sodium and calcium to make modified bentonite, also known as phosphorus locking agent.
The Eutrophication of the water body is mainly due to the excessive phosphorus element in the water body, which will lead to the growth of blue-green algae and consume dissolved oxygen in the water, resulting in widespread death of fish. If not treated in time, the water will stink and the water quality will become worse. The continuous discharge of domestic water and the excessive use of phosphorus containing fertilizers have increased the concentration of phosphorus in the water. Modified bentonite containing lanthanum is added to the water and can effectively adsorb excess phosphorus in the water as it settles to the bottom. When it settles to the bottom, it can also passivate the phosphorus at the water soil interface, prevent the release of phosphorus in the underwater sludge, and control the phosphorus content in the water, In particular, it can enable phosphorus element to capture phosphate in the form of hydrates of lanthanum phosphate, so that algae can not use phosphorus in water, thus inhibiting the growth and reproduction of blue-green algae, and effectively solving the Eutrophication caused by phosphorus in different water bodies such as lakes, reservoirs and rivers.
High purity Lanthanum oxide can also be used to manufacture precision lenses and high refractive optical fiber boards. Lanthanum can also be used to make Night-vision device, so that soldiers can complete combat tasks at night as they do in the daytime. Lanthanum oxide can also be used to manufacture Ceramic capacitor, piezoelectric ceramics and X-ray luminescent materials.
When exploring alternative fossil fuels, people have focused on clean energy hydrogen, and hydrogen storage materials are the key to the application of hydrogen. Due to the flammable and explosive nature of hydrogen, hydrogen storage cylinders can appear exceptionally clumsy. Through continuous exploration, people found that Lanthanum-nickel alloy, a metal hydrogen storage material, has a strong ability to capture hydrogen. It can capture hydrogen molecules and decompose them into hydrogen atoms, and then store the hydrogen atoms in the metal lattice gap to form metal hydride. When these metal hydrides are heated, they will decompose and release hydrogen, which is equivalent to a container for storing hydrogen, but the volume and weight are much smaller than those of steel cylinders, so they can be used to make anode materials for rechargeable Nickel–metal hydride battery and hybrid electric vehicles.
Post time: Aug-01-2023