What Is Molybdenum?
Molybdenum is a type of metal. Its atomic number is 42 and the element symbol is Mo.
In industrial products, it is used as molybdenum sulfide for lubrication purposes and as an anti-seizing agent. It may also be used as an additive in steel materials.
Uses of Molybdenum
Molybdenum sulfide is rarely used in consumer products, and is more often used in industrial applications.
It is used in lubricants for special applications. It is a material that, when blended in oils and greases, improves heat resistance temperatures and load bearing capacity. Thus, it is sometimes used as an anti-seizing agent for bolts. In other cases, it is used as a solid lubricant for oilless bushings.
It may also be used as an additive for steel materials. Chromium molybdenum steel, to which chromium and molybdenum are added to iron, is robust and supple. For this reason, it is sometimes used as an automotive material.
Properties of Molybdenum
Molybdenum is a rare metal. It has a high melting point, a high boiling point, and high strength at high temperatures. It is not used as a conductive material due to its high electrical resistance and high cost. It has a low coefficient of thermal expansion and is not subject to much distortion even at high temperatures.
Principle of Molybdenum
Molybdenum is a silvery metal that is solid at room temperature and pressure. It has a very stable structure and is not highly reactive.
Worldwide reserves of pure molybdenum are said to be around 8.5 million tons, most of which are buried in China.
In air, molybdenum forms an oxide film, so it is a pure metal inside. It does not react with sodium hydroxide, but is soluble in sulfuric acid and hydrochloric acid. At high temperatures, it oxidizes in air to form molybdenum oxide.
Other Information on Molybdenum
1. Molybdenum as a Nutrient
Molybdenum works to detoxify toxic components in the body, and also to remove the detoxified components from the body. It is one of the most important nutrients for humans. It is present in about 10 mg in an adult organism, mostly distributed in the liver and kidneys.
An example of Molybdenum’s role is as a capture factor for oxidoreductases such as xanthine oxidase and aldehyde oxidase. A capture factor is a substance other than a protein, such as an organic substance or ion, that activates an enzyme. Redox enzymes activated by a capture factor work to change one substance into another through an enzymatic reaction.
Molybdenum is abundant in legumes, grains, and meats, and according to the Dietary Reference Intakes for 2020, the recommended intake of Molybdenum is about 30 μg/day for adult men and 25 μg/day for adult women. Since we can consume a lot of Molybdenum from our normal diet, it is unlikely that we will have a deficiency of Molybdenum in our bodies. If there is a deficiency, symptoms such as increased heart rate and night blindness may occur.
2. Toxicity of Molybdenum
Ingesting large amounts of Molybdenum can increase uric acid levels in the blood and cause gout-like symptoms. However, such symptoms do not occur with normal dietary intake.
The LD50 (half lethal dose: a measure of acute toxicity) values for oral intake in rats are 188 mg/kg for molybdenum trioxide, 250 mg/kg for sodium molybdate, and 680 kg/mg for diammonium molybdate.
Sodium Molybdenum is a highly hazardous substance. The aerosol irritates the respiratory tract and eyes, and inhalation causes symptoms such as coughing and sore throat. If accidentally ingested orally, symptoms such as nausea and vomiting may occur.