Platinum is a rare and sought-after precious metal that has a number of unique properties. Translated from Spanish, the word "payment" means small silver, some say "silver" this metal received this name because of its grayish-white hue.
Platinum has a high density, making it one of the heaviest precious metals. A piece made of platinum weighs twice as much as a silver piece. A platinum cube with an edge length of 300 mm would have a weight equal to 0.5 tons.
Platinum is a fairly plastic material. From a small piece of platinum, weighing only 30g, you can get a very thin wire that could connect the German city of Cologne and the capital of Russia Moscow.
Platinum does not undergo oxidation and corrosion, having chemical resistance, it is practically insoluble in alkalis and acids. Tsarskaya vodka, prolonged exposure to sulfuric acid and liquid bromine can dissolve platinum.
Platinum has several other good qualities - hardness and refractoriness, which gives platinum products resistance to abrasion and resistance to high temperatures. The melting point of the "silver" is 18430 ° C, and the boiling point is 3890 ° C.
Platinum compounds in nature
There is little platinum in the earth's crust. Platinum is rarely found in its pure form. It is most often found in conjunction with rare metals such as iridium. The rest of the metals belonging to the platinum group (ruthenium, osmium and rhodium) can be found in small concentrations. Platinum is also found in the form of compounds with copper, iron, chromium and nickel, as well as silver.
Platinum in the ore is represented by small grains or inclusions. Especially large nuggets have not been found in nature.
Scope and history of platinum development
The first deposits of platinum were found in South America in the 18th century.
For a long time, platinum did not arouse interest among Europeans. Its price was low.
Later, having learned the unique properties of platinum, people began to use it more often. All this led to an increase in the price of the precious metal.
Platinum is found in small quantities in the earth's crust. Therefore, its price is high. So a platinum cube with a 300 mm edge length has a market value of $ 2.0 million.
Platinum in the jewelry industry
Among jewelers, platinum is rightfully considered the queen of precious metals.
Today, platinum jewelry is a symbol of confidence and solidity.
Today platinum is used both as a piece of jewelry and as a reliable investment project.
The high strength of the metal increases the demand for its production. Platinum wedding rings are the most demanded jewelry. They do not wear out. Wearing them for a long time rarely causes an allergic reaction.
The cost of a gram of platinum ranges from 3.5 to 4.5 thousand rubles.
Along with the jewelry field, platinum is indispensable in the production of high-precision electronic technology and equipment used in scientific research. Platinum is indispensable in instruments designed for accurate measurements.
The photo shows artificially grown crystals of platinum from the gas phase, with smooth edges and a few centimeters in size.Classic laboratory glassware made of noble platinum
Platinum is a weak, reactive, refractory and corrosion resistant metal. Platinum metal is used to make chemical laboratory glassware or so-called platinum crucibles, designed for heating acidic melt or solutions in them. For example, platinum crucibles are resistant to sulfuric acid or its acidic salts. But melts of alkalis, especially in the presence of oxidants, corrode platinum, so it is better to heat alkali metal hydroxides not in platinum dishes, but in silver ones.The photo below shows an example of a classic small platinum crucible. Large crucibles are used for melting special glass and growing semiconductor monocrystals.
Platinum coin
Today, coins made from platinum are issued for investment and collection purposes. The photo below shows an image of an old, extremely rare and expensive platinum coin with a denomination of 12 rubles, made in Russia in 1832. Platinum coin is in excellent condition, well polished and perfectly retained its attractive luster. The great value of this coin is due to its historical value, the precious metal from which this platinum coin was minted, good condition and high weight.
What is Platinum Bar?
The photo below shows two dimensional platinum bars, 999 standard and weighing 10 and 50 grams. Such measured platinum bars can be purchased at the Banks of Russia.Platinum bars can be an excellent investment of spare cash in order to keep your savings from possible inflation. In addition to a profitable investment of capital, platinum bars can be both collectible items and just valuable gifts.
On front side platinum bars are clearly and legibly marked. The imprints of the inscriptions on the ingots can be, depending on the technology of producing the ingots: depressed or convex. A platinum ingot, on the front side, is marked with the following inscriptions: the inscription of the country of origin - "Russia" enclosed in an oval, below are the weights of the bars in grams: 10 and 50 grams, the name of the metal - "platinum", the weight fraction of the noble metal in bars - 999, 5 or its metric 999 standard, the trademark of the manufacturer, at the very bottom is the bar number (for platinum bars weighing 50 grams or less, the number can be printed on the reverse side).
Platinum wedding ring
Platinum is the strongest inert, noble and very beautiful metal. Its properties are used by jewelers to create jewelry. Platinum got its name from the Spanish conquistadors, who discovered this metal in the middle of the 16th century, in South America (today this is the territory of the modern state of Colombia).Initially, platinum had no practical value. People did not know the properties of this metal. They did not know how to melt platinum, because they did not know its melting point. The metal was difficult to melt. Platinum was valued at half the value of mined silver.
Today the properties of platinum are appreciated. Platinum is the most expensive precious metal. Jewelry made of platinum looks very beautiful and attractive.
The photo below shows a platinum engagement ring, high purity and well polished to a high shine. If you take one at a time: a silver, gold and platinum ring, of the same volume, then in your hands you can feel a clear difference in their weight. A ring made of platinum, by weight, will naturally be heavier.
Platinum watch - chronograph
The photo shows the men's platinum watch. They represent a classic and popular chronograph, with a built-in Swiss movement - ETA 7750. The platinum watch has a mechanical self-winding movement. This chronograph is a Russian brand from the Platinor company. The watch case is made of 950 platinum and is framed with diamonds along the edge. And the strap of the platinum watch is made of palladium 850. The watch has a classic look and does not contain anything superfluous in its design. The glasses of such watches are sapphire, which means that such glasses will not be scratched. Although such sapphire crystals are easily shattered. Therefore, the watch should not be dropped or hit. Platinum watches are protected from moisture and water. Wearing the watch on your wrist, you can swim in water, wash your hands or wash dishes. However, you cannot switch the chronometer buttons of the watch underwater.Platinum and palladium are metals belonging to the platinum group of noble metals. They are considered rare on earth metal. They have high density and viscosity. Processing platinum and palladium requires a very high level of professionalism. Platinum is a very hard metal and is difficult to machine. In order to make a platinum watch case, you will need more than one grinding wheel, since polishing wheels are often erased during polishing.
Platinum is an expensive precious metal compared to other precious metals. Therefore, its high cost is noticeably reflected in the price of platinum watches.
Palladium is a noble metal from the group of platinum elements, it is priced cheaper than gold, but in jewelry it is more expensive than gold metal, since it is a very difficult metal to process. In Russia, palladium jewelry is practically not produced, since it is unprofitable for the manufacturer to contact this metal. In Japan, palladium jewelry is highly prized and easily snapped up.
Spongy platinum and platinum black
Platinum is the strongest inert, chemically inactive metal and has a catalytic ability. However, spongy platinum acquires completely different properties that are not inherent in ordinary platinum.Spongy platinum is a gray spongy mass that is obtained by heating some platinum compounds. Platinum in such a spongy form has the ability to absorb various gases. This is explained by the fact that spongy platinum has a large surface area.
One volume of spongy platinum can hold several hundred volumes of oxygen. Such oxygen-rich spongy platinum has the ability to oxidize various substances (alcohol, sulfur dioxide, hydrogen, organic substances). Under normal room conditions, these substances are not able to combine with oxygen. And spongy platinum, possessing catalytic properties, promotes the oxidation of various substances with oxygen.
The oxidizing ability of spongy platinum is widely used in chemical laboratories and engineering. For example, the oxidizing ability of spongy platinum is very clearly manifested when it acts on an explosive gas (it is a mixture of hydrogen and oxygen). At first, the reaction is accompanied by a slow burning of hydrogen, and then when the spongy platinum is heated up, an explosion occurs.
In its usual form, platinum has poor catalytic properties. The spiral wire over the extinguished wick of the alcohol burner will slowly smolder after blowing out the flame, as alcohol vapors are slowly oxidized under the spiral.
In order for the catalytic reaction to proceed more intensively, both spongy platinum and platinum black are used. What is platinum rabble? Platinum black is a fine or finely dispersed powder of metallic platinum, which is obtained by the reduction of its compounds and is used as a catalyst in various chemical reactions. Finely ground platinum metal itself does not enter into chemical reactions with various substances, but only contributes to the occurrence of certain chemical reactions.
The photograph on the left is spongy platinum, and on the right is platinum black.
White gold
White gold is an alloy of gold metal with other metals (silver, platinum, nickel, palladium) that color gold in White color... If 585 fineness of gold is an alloy consisting of 585 parts by weight of pure gold and ligature metals: copper and silver, then the same 585 is an alloy containing 585 parts by weight of pure metal, only platinum is added to the alloy instead of copper, or which color the gold in white. With a high content of silver in an alloy with gold, the alloy is painted in a white - matte color.The photo below shows two wedding rings made of white gold alloy.
Platinum candles
The photo below shows automotive platinum spark plugs with platinum contacts. Platinum spark plugs, which serve as ignition in internal combustion engines, are so named because refractory platinum is used to make electrodes. Platinum electrodes in candles are good because they have high corrosion resistance and high temperature resistance. Platinum electrodes practically do not burn out and they can be used for a very long time. The platinum electrode allows the distance between the side and inner electrodes to remain constant for a very long period of time. An important characteristic of platinum spark plugs is the size of the gap between the inner and side electrodes, since the efficiency of the ignition of the gas mixture in the engine cylinder depends on this. The high resistance of platinum to erosion makes it possible to extend the drain interval up to 90,000 kilometers.
Physical properties of platinum
Platinum history
Platinum isotopes
Platinum deposits
Chemical properties of platinum
Mining and production of platinum
Platinum Applications
Platinum is a heavy metal. In terms of its chemical and physical properties, platinum is very similar to gold, mercury, thallium, lead and bismuth. Platinum can have a toxic effect on the human body, that is, cause poisoning. Platinum is not only a beautiful metal, but also a poison. A lethal dose of platinum leading to death is 1 - 2 grams. Platinum oxide has a cauterizing effect on the skin. There are cases when, upon contact with platinum, changes were observed in the skin of nails and brushes. Platinum trioxide causes dermatitis.
Among all the noble metals, platinum occupies a special place and its cost is higher in comparison with gold and silver. The fact is that the extraction of this substance is a rather laborious process, and it is also rare. The higher cost of Platinum is due at least to the fact that it takes about 10 tons of rock to be processed to produce one ounce. In turn, to create a similar amount of gold, it takes about 3 tons of ore.
Even before our era, people knew about the metal platinum, for example, the ancient Egyptians used it to make jewelry. It was widely used by the Indians of the Inca tribe, but was gradually forgotten. Recent history mining and processing of platinum dates back to the period of the development of America by the Spanish conquistadors.
However, at first, the metal was not given due attention, as evidenced by even its name - translated from Spanish the word it means "small silver". Often it was considered unripe gold at all and was thrown away. It's a pretty refractory metal., with a high density index, which made it much more difficult to process.
But after the discovery of one unique ability, the situation changed - platinum and gold are easily fused. Jewelers were the first to take advantage of this feature, starting to add it to gold: jewelry made from the new alloy had a lower cost. At the same time, the high density of the metal contributed to an increase in the weight of the finished product, but this was more than offset by the addition of silver, which did not affect the shade in any way.
For a long time, it was not possible to distinguish such jewelry from ordinary ones. When this did happen, the import of platinum was even banned for some time in Europe. Platinum was recognized as an independent chemical element only in the 18th century, when scientists were able to carefully study the properties of the metal.
The first platinum deposits in Russia were discovered near Yekaterinburg in 1819. Five years later, new deposits were found in the Nizhniy Tagil District, and they are so vast that Russia quickly took a leading position in metal mining.
Physical and chemical properties
The opinion that platinum is white gold is still common among ordinary people. In fact, it is an independent chemical element with unique properties. First, about how platinum is indicated - Platinum or Pt. In the periodic table of chemical elements, this is one of the heaviest metals. He conceded the palm only to osmium and iridium, which also belong to the substances of the platinum group.
Among the properties of the metal, the most unique are worth noting:
- When heated to temperatures below 200 degrees, it is not subject to oxidation and does not enter into chemical interaction with other substances.
- Indicators of hardness and density are higher in comparison with gold and even more so with silver.
- Differs in high ductility and lends itself well to forging.
- It has excellent electrical conductivity.
- Does not interact with acids, except aqua regia.
- It has a high melting point of 1768.3 degrees.
Pure metal is practically not found in nature, and if we talk about what platinum consists of, then most often these are alloys with rhodium, palladium, iron, iridium and some other substances.
The oxidation rate depends on the oxygen pressure and the rate of oxygen supply to the metal surface. Since it is most often mined in the form of alloys, the presence of other substances in them slows down this process.
The most common oxides are:
The specific resistance of platinum is relatively small, but in terms of electrical conductivity, it is inferior to aluminum, silver, and copper. In this case, during heating, the resistivity index increases, and the specific conductivity decreases accordingly. Scientists explain this fact by the fact that as the temperature rises, the particles that make up platinum begin to move chaotically and, as a result, the passage of current becomes difficult.
The industry actively uses the ability of platinum to accelerate various chemical reactions, which makes it an excellent catalyst.
Application area
In medicine, metal compounds, mainly amminoplastinates, are used in the treatment of various forms of cancer. The first such drug was cisplastin, but currently oxaliplatin and carboplatin are the most popular. The use of metal in technology is much wider. If we talk about where platinum is contained, the main directions can be noted:
Since about the middle of the 18th century, platinum has served as a monetary function in Russia. Exactly the first platinum coins were produced in the Russian Empire, and it happened in 1828. Currently, some states continue to mint coins of various denominations, but they are most often used for investment. It should also be said about the jewelry industry, which annually consumes about 50 tons of metal. Platinum jewelry is most popular in Japan.
Platinum is a noble metal, which is not widespread in nature; it is grayish-white and shiny in color. Of the main precious metals, platinum is the most expensive, more expensive and The reason is that this metal is heavier - a piece of the same volume in platinum performance will have a greater weight than in gold or silver. In addition, the price increases due to its rarity and complexity in processing (cleaning the rock).
The history of platinum is the most unusual of all precious metals. Unlike gold and silver, which have been valued since time immemorial, platinum began to be highly valued only "recently", about 250-300 years ago. This is most clearly demonstrated by the origin of the name platinum. Plata- in Spanish means "silver", and platina- "silver", "small silver". This contemptuous name was given by the Spanish colonialists to an unknown metal, which they met when mining gold in South America. Platinum grains obtained during the washing of gold-bearing rock were sometimes combined with gold. They had to be separated manually, which greatly complicated the whole process, and sometimes made development impractical. And by virtue of its high temperature melting in 1768.3 ° C(melting temperature of silver 962 ° C, gold 1064.18 ° C), platinum was not available for isolation in its pure form and processing by methods known at that time.
People have repeatedly encountered platinum since time immemorial, but did not attach any importance to it. It was usually mistaken for the wrong silver or unripe gold in the ground, and was simply thrown away. A famous example is the finding of a strip of platinum on a box studded with gold and silver, found in the area of ancient Fif in Egypt. Scientists have established that the ancient master in about the 7th century BC. did not attach any importance to platinum, simply mistaking it for silver.
The exception is the Indians of South America, who lived in the territory of modern Ecuador and Colombia. They possessed a unique technique of processing platinum and making jewelry out of it.
In all the known works on chemistry and mineralogy (and in any other literature) until the middle of the 16th century, there is not a single description of platinum as a separate element. Platinum is first mentioned in the work Julius Caesar Scaliger "Exotericarum Exercitationum" published in Paris 1557.
We can say that platinum was only discovered in 1748, when Antonio de Uloa, a naval officer and mathematician, presented his report on a trip to South America to the scientific community.
From that moment, an active study of platinum began, and its first samples began to arrive in Europe.
Platinum is a rare shiny metal with a silvery color. It occupies a special place among other precious metals, being usually more expensive than gold and silver.
This is due to the fact that platinum mining is an extremely laborious process and this metal is very rare. For example, to obtain one ounce of gold, it is enough to refine three tons of ore, and to extract the same amount of platinum, you need to process up to ten tons of rock.
History of metal use
Platinum has been around since BC. It was used in ancient Egypt to make a variety of jewelry. It was also common among the Inca tribes, but over time it was forgotten. In the photo you can see platinum items discovered by archaeologists:
Only after a long time, the discovery of this substance happened thanks to Spanish travelers who were exploring South America. Initially, it was not appreciated at its true worth, as the name suggests. Platina can be translated from Spanish as “little silver”.
Accordingly, platinum was valued much less than precious metals. Often it was even considered immature gold or irregular silver (due to its color) and was simply thrown away. It is characterized by high melting point and high density. Therefore, it was considered unfit for any use.
However, then an interesting property was discovered - this precious metal has the ability to easily alloy with gold. Jewelers took this into service and actively began to mix platinum into gold items, thereby lowering the cost of their manufacture. Moreover, this was done so skillfully that it was almost impossible to detect a fake. Due to the high density of platinum, even its small volume increased the weight of the finished product, but this was compensated by the addition of a certain amount of silver to the alloy, which did not affect the color. Such a fraud was nevertheless recognized, and the import of the precious metal into Europe was prohibited by law for some time.
Platinum was recognized as an independent chemical element only in the middle of the eighteenth century. A careful study of its qualities made it possible to find the first application of this metal.
The physical and operational properties of platinum, especially resistance to various influences and high density, served as the basis for making useful equipment from it. In particular, platinum retorts have been successfully used for the concentration of corrosive sulfuric acid.
Such vessels were originally made using forging or pressing, since at that time scientific progress could not provide the required temperature in furnaces for melting. By the end of the nineteenth century, it was possible to melt platinum using the flame arising from the combustion of an oxyhydrogen gas.
Platinum in Russia
The history of this noble metal in Russia dates back to 1819, when it was first found in the Urals, near Yekaterinburg. Five years later, platinum deposits were found in the Nizhniy Tagil district. The placers turned out to be so abundant that Russia quickly became the world's leader in terms of production.
The photo shows the largest nugget from these deposits:
Its weight was 12 kg (unfortunately, it was later melted down).
Ural platinum was actively bought out by foreign companies, especially after an industrial method was developed for cleaning it from impurities and creating pure silver bars. Initially, it was in great demand abroad in England and France, later the USA and Germany joined them.
In the process of research, scientists have discovered some of the elements that make up native platinum. Palladium and rhodium were the first to replenish the periodic table, later iridium and osmium were isolated. And the final element in the platinum group was ruthenium, discovered in 1844.
Due to the fact that the volumes of platinum mined in the Urals were extremely high and most of the metal simply did not find a worthy application, in 1828 it was decided to issue platinum coins. The photo shows the first coins from this precious metal produced in Russia.
By that time, a way had already been found to produce various high quality products. This method, called powder metallurgy, is still widely used today. At the moment, Russian coins of the 19th century made of platinum are of colossal value. The cost of one copy can go up to $ 5,000.
For jewelry making, most of the platinum mined was used until the middle of the twentieth century, after which it began to be used more often for technical purposes. It is used in the following industries:
- Automotive (for the manufacture of catalysts);
- Electrical engineering (creation of elements for electric furnaces exposed to high temperatures);
- Petrochemical and organic synthesis;
- Ammonia synthesis.
It is also used in the manufacture of parts for glass furnaces, a variety of laboratory equipment, equipment for industries where resistance to chemical and temperature influences is required.
Basic properties
One often hears the opinion that platinum and white gold are one and the same. But in fact, such a statement is fundamentally wrong, they are similar only in color.
Platinum is a chemical element of the periodic table (natural classification of elements by the electronic structure of atoms), with its own characteristic properties. Although in the photo you can notice some similarities with white gold in appearance.
It is a silver-colored precious metal, but it still looks a little different from silver. It also differs from others in its characteristics and methods of application.
Physical and chemical properties of platinum
This element is a refractory metal with a high density, for its melting a temperature of 1769 degrees Celsius is required, and for boiling - 3800 degrees, which is due to the low specific thermal conductivity.
It is also one of the heaviest metals in the periodic table. According to this indicator, it is surpassed only by two other elements of the platinum group - osmium and iridium. The density under normal conditions is 21.45 grams per square decimeter. The specific gravity is 21.45 grams per cubic centimeter. This figure is higher than that of gold and is almost twice the specific gravity of silver.
The hardness of platinum is another quality that gave it its use in industry and jewelry. Resistance to various external influences makes the process of processing and manufacturing of products more laborious, but its operational properties more than compensate for such inconveniences.
For example, jewelry can be made entirely from pure platinum, while gold and silver require other materials in the composition to ensure durability.
It is also worth noting the high ductility of this metal. It can be used to make the thinnest sheet of foil or lightweight wire without losing its basic properties.
Platinum is a member of the group of noble metals, as it does not have the ability to oxidize and resists corrosion. The high inertness of the metal does not allow interaction with acids or alkalis. It can be dissolved only in aqua regia and liquid bromine, subject to dissolution upon prolonged exposure to hot sulfuric acid.
When this substance is heated, the possibility of interaction with other chemical elements, substances and alloys increases. An increase in temperature makes it possible to obtain platinum oxide, which forms on the surface of the metal. There are several varieties of it that are easy to distinguish by color.
The most famous are:
- Black PtO (dark gray);
- Platinum oxide PtO2 (brown);
- PtO3 oxide (red-brown color).
The speed and degree of oxidation of this metal directly depends on how freely oxygen flows to the surface and what its pressure is. Other metals located on the platinum surface can serve as an obstacle to oxidation. Therefore, the greatest oxidation should be expected from a pure metal without any impurities.
Platinum can exhibit different oxidation states depending on the specific compound. This indicator ranges from 0 to +8.
Having a fairly low specific resistance, this metal is a good conductor, inferior in this property to aluminum, copper and silver. The resistivity index is close to that of iron.
Accordingly, the specific conductivity of platinum (the reciprocal of the specific resistance) occupies a similar position among other elements of the periodic table. Since it is a conductor, its resistivity increases as it heats up, while its conductivity, on the contrary, decreases. This property is due to the fact that the particles in the composition of platinum begin to move in a chaotic manner with increasing temperature. And this, in turn, creates obstacles for the passage of electric current.
One of the most important qualities that is widely used in production is the property of this noble metal to act as a catalyst for numerous chemical reactions. It is usually used in an alloy with rhodium or as platinum black - a fine powder of a characteristic black color obtained as a result of the reduction of compounds.
Platinum resistance thermometers are now quite widespread (illustrated in the photo). This is due to the fact that this substance is practically not subject to corrosion, has a high degree of plasticity, inertness and makes it possible to use pure metal for production. An important role is played by such qualities as high resistivity and significant temperature coefficient of resistance.
Output
Most people think of platinum as a very expensive silver-white metal that is used to make jewelry. However, due to its many properties, it has become widespread in various fields of human activity, from medicine to the automotive industry.
Although in the entire history of the exploitation of platinum it has never been used as money, investing in platinum is considered a fairly profitable form of investment. One ounce of this metal is $ 270 more expensive than the same amount of gold. If you constantly monitor the price of precious metals, you can get a good profit.
