The most expensive of the three noble metals is, of course, platinum. According to its prevalence in the earth's crust, it is one of the rarest elements. In its pure form, platinum is almost never found and is very expensive. Despite this, the use of platinum in various sectors of the national economy is indeed very widespread. In some cases, this metal can even be indispensable.
Discovery story
All platinum nuggets found to date represent its alloys with iridium, palladium, osmium, iron and rhodium. Sometimes there are also compounds of this metal with nickel or copper. In its pure form, platinum itself is a metal of a brilliant white-silver hue. It owes its name to the Spanish conquistador who conquered South America. Outwardly, platinum is very similar to silver, but is much more refractory. The Spanish conquistadors, who discovered a metal similar to silver in South America, simply threw it at first. At the same time, the conquerors contemptuously called him platina , which means “silver” in translation.
In our country, platinum was discovered in 1819. Its industrial production began five years later. Initially, the use of platinum was limited in Russia mainly to metallurgy. Used it as an additive in the production of high quality steels. However, in 1828, platinum found another application. Then, on the decree of the tsar, the Russian mint began minting money from this metal .
In its pure form, e platinum was obtained only in 1859 by the chemist Devel. Initially, it was mined in Russia exclusively at the Verkh-Isetsky, Bilimbaevsky and Nevyansky mines. In 1824, other rich deposits were discovered .
Chemical and physical characteristics
Platinum is a metal belonging to the group of the 6th transition period of the Mendeleev system. Its main properties are:
In hot form, platinum is well welded and rolled. Also, this metal can absorb oxygen quite strongly. The table below shows the main characteristics of platinum:
The main properties of platinumCharacteristic | Parameter |
Density | 21.45 g / dm 3 |
The melting temperature | 1769 s |
Electrical resistivity | 9.85 μOhm · cm |
Hardness | 390-420 MPa |
Elasticity | 173 GPa |
The widespread use of platinum in industry, medicine, and other sectors of the national economy is justified, among other things, by its chemical stability. This metal is dissolved only in aqua regia and in bromine. When heated, platinum can only react with a small group of substances.
The main areas of platinum use
The use of platinum in the jewelry industry is justified primarily by its nobility, rarity and beauty. In this way, up to the middle of the last century, this metal was mainly used. Only a few percent of the total volume of platinum mined was used by doctors and dentists. Today, the growth in demand for this noble metal is growing steadily. The unique physical and chemical properties of platinum, in addition to jewelry production, make it extremely popular in a variety of industries and national economies:
This noble metal is used, of course, in banking.
The use of platinum in the jewelry industry
Of course, this metal is most widely used for the manufacture of various kinds of jewelry. About 50 tons of platinum are used annually in the global jewelry industry. A variety of jewelry can be made from this metal. Platinum rings, as well as chains, earrings, bracelets and necklaces, are not only beautiful, but also durable.
The most popular in the jewelry industry is the metal of the 950th test. Such an alloy includes 95% of platinum itself and 5% of iridium. A metal of this composition has a high degree of elasticity and hardness. Chains, bracelets and rings made of platinum in an alloy with iridium can last as long as possible.
Application in the production of nitric acid and other chemicals
In technology, platinum is used primarily as a catalyst. It is this metal that is the best oxidizing agent of ammonia to NO in the production of nitric acid. It is used in this case, usually in the form of a mesh of wire with a diameter of 0.05-0.09 mm . In the production of nitric acid, it is most often used not pure platinum, but its alloy with rhodium. This allows you to slightly reduce the cost of the catalyst, increases its activity and increases the shelf life.
Platinum is used in the technical industry, of course, not only in the production of nitric acid. Catalysts made of this metal can accelerate many other chemical reactions. Platinum is used, for example, in the hydrogenation of aromatic and industrial hydrocarbons, ketones, acetylene, etc. This metal is also used in sulfuric acid production to produce SO 3 or SO 2 .
Refining Application
In industrial enterprises of this specialization, platinum is actually used quite widely. In this case, it is also used as a catalyst. In oil refining, gas is produced with the help of this metal in special plants. Of course, high quality. In the oil refining industry, platinum is used not in the form of a grid, but in the form of a fine powder. In addition to gasoline, technical hydrogen and aromatic hydrocarbons are also obtained using this metal.
Of course, other catalysts can be used in the oil refining industry - molybdenum, aluminum, etc. However, platinum in comparison with them has such undeniable advantages as durability, high activity, and increased efficiency.
The use of platinum in electrical engineering and instrumentation
One of the advantages of this metal is that it has stable electrical and mechanical properties. This has made platinum extremely popular in such sectors of the economy as:
The use of platinum in electronics allows us to produce high-quality contacts of high-precision devices. In this case, the metal is usually used in an alloy with iridium. Very often, for example, platinum is used for the manufacture of contacts of resistance furnaces and various kinds of devices operating from a network . Sometimes an alloy of this metal with cobalt is also used in technology. Such material is used in the manufacture of magnets, which have tremendous attractive forces at small sizes.
The use of platinum in the automotive and space industries
In these areas of the national economy, platinum has also found quite widespread use . In the automotive industry, this metal is most often used as a catalyst in exhaust gas neutralizers. In this case, it is used as a spray in ceramic monoliths.
In the space industry and aircraft construction, this metal is mainly used for the manufacture of fuel cell electrodes. Similarly, platinum was used, for example, in all spacecraft of the Apollo series.
Use in medicine
The use of platinum in this area allows you to save the lives of thousands of patients. The value of this metal in this case is that there are no analogues to it in medicine. For example, special surgical instruments are made from platinum, which can be sterilized in the flame of an alcohol burner. With this treatment, they, unlike those made from other metals, do not oxidize.
Platinum, the use of which in medicine is not limited to surgery, of course, can also be used in dentistry, cardiology and hearing prosthetics. Often, for example, it is used as a sprayer in the manufacture of tools intended for dental treatment. In cardiology and hearing prosthetics, electrodes made of its alloy with iridium are used . They are used mainly to stimulate cardiac activity. They are also often used for the manufacture of implants intended for people with hearing loss.
The use of platinum in the glass industry
Platinum is a metal, among other things, widely used in the manufacture of high-quality optics. Also, it is often used in the alloy with rhodium in the manufacture of glass fiber dies a , whose thickness often does not exceed 1 μm. Such a metal is able to easily withstand thousands of hours of heating up to 1450 C. Also, the alloy of rhodium with platinum practically does not react to strong temperature extremes and is resistant to corrosion.
Among other things, this metal is also very often used in the production of various kinds of equipment intended for the manufacture of high-quality glass. Such mechanisms are not deformed or oxidized during production. Also, they do not react with the glass itself. Very often in this industry, for example, platinum crucibles are used. It is in them that the widely known and very expensive Czech glass is made.
Chemical industry applications
In this case, platinum is also used mainly for the manufacture of crucibles and other laboratory equipment - cups, resistance thermometers, etc. Such products are used mainly in the manufacture of various kinds of ultrapure substances. In semiconductor crystals, for example, there should not be a single foreign atom per million of its own. It is these results that make it possible to use platinum equipment.
Instead of a conclusion
The use of platinum in the above areas is appropriate and justified . But of course, this metal can be used in other sectors of the national economy. For example, crucibles are often made from platinum, which are used in growing crystals for lasers and contacts using low current techniques. Also, compass needle holders are made from this metal, they are used in anti-aging cosmetic creams and lotions, anti-cancer drugs, etc.