00:00What is molybdenum?
00:08Today, we are going to talk about a chemical element that, although not very well known
00:13by the general public, is used in essential everyday applications, from the steel in the
00:20structures that surround us, to components of space equipment, molybdenum. And to start,
00:27let's understand the basics. What is molybdenum? It is a chemical element with the symbol MO,
00:33and atomic number 42, on the periodic table. It is a transition metal element, with a silvery
00:41color which belongs to the group of refractory metals, which are characterized by having extremely
00:49high melting points. Molybdenum has one of the highest melting points among all known elements.
00:57At 2,623 degrees Celsius, exceeding the melting point of regular steel by more than a thousand
01:06degrees. To give you an idea, few materials in nature can maintain their mechanical properties
01:12at temperatures of this magnitude. Its density is approximately 10.2 grams per cubic centimeter,
01:19which places it among the heavy metals with a value close to that of lead. An important characteristic
01:26of molybdenum is that it does not react with oxygen or water at room temperature, giving this material
01:34a natural resistance to corrosion under normal conditions of use. But how was this element discovered?
01:41The history of molybdenum begins with a confusion that lasted for centuries. The mineral from which molybdenum
01:50is extracted is called molybdenite, and it has an appearance, texture, and even properties similar to
01:58those of graphite and lead ore, known as galena. Because of these similarities, for a long time, molybdenite was
02:08mistaken for land. And the name of the element itself comes from the Greek molybdenus,
02:15which, guess what, means lead. This confusion lasted until 1778, when the Swedish chemist,
02:24Carro Wilhelm Scheele, who also played a key role in the discovery of oxygen, analyzed molybdenite.
02:31And he chemically demonstrated that it was a compound containing an element that was previously unknown.
02:39Scheele was not able to isolate the metal, so he passed the challenge to his colleague Peter Jacob
02:45Hill, who, in 1781, produced metallic molybdenum for the first time by grinding molybdenic acid
02:55with carbon in linseed oil and heating the mixture to high temperatures. And where is molybdenum found
03:02in nature? Molybdenum does not occur in its pure metallic form on earth, being found only combined with
03:11other elements in minerals. It is the 53rd most abundant element in the earth's crust, which means
03:19it is not particularly common compared to other elements. The most important mineral as a source
03:26of molybdenum is molybdenite, whose chemical formula is MOS2, which is molybdenum sulfide.
03:35The largest global reserves are concentrated in a few countries, with China holding approximately 39%
03:43of the world's reserves, followed by the United States, Peru and Chile. Now, how is this material
03:51extracted and processed? The extraction of molybdenum depends on the type of mineral deposit in which it
03:58is found, but it is generally carried out to open pit or underground mining. Once extracted, the ore goes
04:06through crushing, grinding and flotation process to concentrate the molybdenite from the other minerals
04:16present in the rock. The resulting concentrate is then subjected to a process called roasting, in which it is
04:25heated to high temperatures to convert molybdenum sulfide into molybdenum oxide. This oxide can then be
04:34transformed into ferromolybdenum, which is the form most used by the steel industry. But what is molybdenum
04:43used for and why is it so important? Although the element was isolated in 1781, it was only at the
04:51end of the
04:5219th century that French metallurgists discovered that molybdenum, when added to steel in small amounts,
05:02resulted in a significantly stronger material. Following this discovery, most of the world's
05:10consumption of molybdenum began to be used to make metal alloys, mainly steel and cast iron. When added to
05:19steel, even in small proportions, molybdenum increases the mechanical strength of the material,
05:28its resistance to corrosion and its ability to withstand high temperatures without losing its
05:34structural properties. This is particularly important in applications where the material operates under
05:41extreme temperature and pressure conditions. Steels alloyed with molybdenum are widely used in pipelines for
05:49the oil and gas industry, turbine components, chemical processing equipment, and even in rifle barrels
05:57and armor for military applications. It is also an essential component in the manufacture of super
06:04alloys, which are materials specifically developed to operate at high temperatures. It is also found in the
06:13internal components of jet engines and gas turbines. But does it have applications beyond metal alloys?
06:22Yes, and one of the most interesting involves precisely the mineral from which it is extracted.
06:28Molybdenum sulfide has a crystalline structure organized in layers that can easily slide over each other.
06:41This gives the material exceptional lubricating properties. Historically, molybdenite was used as a
06:49solid lubricant in a way very similar to graphite. And to this day, molybdenum disulfide is used where
06:58conventional lubricants do not work properly, such as in high vacuum environments, extreme temperatures,
07:06or under radiation. Typical conditions for molybdenite. It is used to operate at high temperatures.
07:11It's interesting to note that the same mineral that confused our ancestors, because it looked like
07:19lead or graphite, has lubricating properties comparable to those of graphite, which partly explains this
07:27historical confusion. But is molybdenum important only for industry? No. And this is the aspect that
07:35surprises a lot of people. It is also classified as an essential element for life, necessary for all
07:43living organisms, from bacteria to human beings. In our body, molybdenum acts as a cofacto for enzymes,
07:52which are proteins responsible for facilitating vital chemical reactions for metabolism,
07:59including processes for detoxifying sulfur compounds in the body. The amount required for humans is very
08:07small, on the order of micrograms per day. And deficiency is extremely rare, since the element is
08:16present in various foods, such as legumes, whole grains, and leafy vegetables. In the plant world, molybdenum plays a
08:26particularly important role, because it is a component of enzymes found in soil bacteria that are capable of
08:35fixing atmospheric nitrogen, converting it into forms that plants can absorb and use as a nutrient.
08:44This process of nitrogen fixation is fundamental for the natural fertility of the soil and for
08:50agricultural productivity. And it's fascinating to realize how the engineering of nature,
08:55and that of large structures, depends on solid foundations working behind the scenes.
09:02Because molybdenum has other applications you may not know about. Besides what we've already talked about,
09:09molybdenum is used in the manufacture of electrodes for industrial glass melting furnaces,
09:16due to its ability to withstand high temperatures without contaminating the molten material.
09:22It is also used in the manufacture of filaments and in components of electronic equipment that require
09:30materials with high thermal resistance. In the chemical field, molybdenum compounds are used as
09:38catalysts in industrial processes, including petroleum refining. Interestingly, pure metallic molybdenum,
09:46in its elemental form has never been found in nature on Earth, occurring only in compounds with other elements.
09:54However, the Soviet space mission, Luna 24, in 1976, brought back from the Moon a small sample that contained
10:05molybdenum in its pure form. A discovery that illustrates how geological conditions on other celestial bodies
10:13can differ from those we find on our planet. Your opinion is important to us. So, if you liked the
10:20video,
10:20subscribe to the channel, if you haven't already, and leave a like on the video. And if you want to
10:26help us
10:27produce this and many other types of content here on the platform, consider becoming a member. And help us
10:34out with a coffee, with some cheese bread, and get a shout out in our videos. Are you looking to
10:40grow
10:40professionally or develop a new technical skill? Scan the QR code or the link in the description, and you'll
10:47find a page with all the courses we recommend. And you? Did you know about molybdenum and its applications?
10:56Did you know it's present in the steel of so many structures around you, and that it's essential for
11:02your life? Tell me here in the comments. I want to know. Here on the side, there are two interesting
11:08video options that you need to watch to expand your knowledge and explore your curiosity. And if you want
11:13to support us, give the video a like, subscribe to the channel, turn on the notification bell,
11:18and consider becoming a channel member. That's it, Engineering Enthusiasts. Take care, and I'll see you
11:24in the next video.
Comments