The precious metal is platinum. Platinum - the queen of precious metals The strength of platinum

Overview of the properties and applications of a dense metal - platinum.

Platinum It is a dense, stable, and rare metal often used in jewelry for its attractive, silvery appearance, as well as medical, electronic, and chemical applications due to its unique chemical and physical properties.

Properties of platinum metal:

Platinum metal has a number of useful properties which explains its use in a wide variety of industries. It is one of the densest metallic elements—nearly twice as dense as lead—and is very stable, giving the metal excellent corrosion-resistant properties. A good conductor of electricity, platinum is also malleable and ductile.

Platinum is considered a biocompatible metal because it is non-toxic and stable, so it does not react or adversely affect body tissues. Recent studies have also shown that platinum inhibits the growth of certain cancer cells.

History of platinum

An alloy of the Platinum Group Metals (PGMs), which includes platinum, was used to decorate the Thebe Casket, an Egyptian tomb that dates back to about 700BC. This is the earliest known use of platinum, although pre-Columbian South Americans also made jewelry in gold and platinum alloys.

The Spanish conquistadors were the first Europeans to encounter the metal, although they were not comfortable chasing silver due to its similar appearance. They named the metal Platinum - a version of Plata, the Spanish word for silver - or Platina del Pinto because of its discovery in the sands along the banks of the Pinto River in present-day Colombia.

Although he studied a number of English, French and Spanish chemists in the mid-18th century, François Chabano was the first to produce a pure sample of the platinum metal in 1783. In 1801, the Englishman William Wollaston discovered a method for effectively extracting the metal from ore, which is very similar to process used today.

The silver appearance of the platinum metal quickly made it a prized commodity among royalty and the wealthy, who were looking for jewelry made from the latest precious metal.

Growing demand led to the discovery of large deposits in the Ural Mountains in 1824 and in Canada in 1888, but the conclusion that would fundamentally change the future of platinum did not come until 1924, when a farmer in South Africa stumbled over a platinum nugget in a riverbed. This eventually led to the discovery by geologist Hans Merensky of the Bushveld magnesium deposit, the largest platinum deposit on Earth.

While some industrial applications for platinum (such as spark plug coatings) were in use by the mid-20th century, most modern electronic, medical, and automotive applications have only been developed since 1974, when U.S. air quality regulations initiated the autocatalyst era.

Since then, platinum has also become an investment vehicle and is traded on the New York Mercantile Exchange and the London Platinum and Palladium Market.

Platinum production

Although platinum is most commonly found naturally in alluvial deposits, platinum and platinum group (PGM) miners typically extract the metal from sperrylite and co-op, with two platinum-bearing ores.

Platinum is always found next to other PGMs. In the South African Bushveld complex and a limited number of other orebodies, PGM occurs in sufficient quantities to make extraction of these metals economically exclusive; while the Russian deposits of Norilsk and Canada at Sudbury produce platinum and other PGMs as by-products of nickel and copper.

The extraction of platinum from ore is capital and labor intensive. It can take up to 6 months and 7 to 12 tons of ore to produce one troy ounce (31.135 g) of pure platinum.

The first stage of this process is the grinding of platinum ore and its immersion in a reagent containing water; a process known as "froth flotation".

During flotation, air is pumped through the ore-water slurry. The platinum particles chemically attach themselves to oxygen and rise to the surface in a foam that is discarded for further purification.

After drying, the concentrated powder still contains less than 1% platinum. It is then heated to over 2,732 °F (1,500 °C) in electric furnaces and the air is purged again, removing iron and sulfur impurities.

Electrolytic and chemical methods are used to recover nickel, copper and cobalt, resulting in a concentrate of 15-20% PGM.

Aqua regia (a mixture of nitric acid and hydrochloric acid) is used to dissolve the platinum metal from the mineral concentrate by creating chlorine, which attaches to the platinum to form chloroplatinic acid.

In the last step, ammonium chloride is used to convert chloroplatinic acid to ammonium hexachloroplatinate, which can be burned to form pure platinum metal.

The good news is that not all platinum is made from primary sources in this long and expensive process. According to statistics from the US Geological Survey (USGS), about 30% of the 8.53 million ounces of platinum produced worldwide in 2012 comes from recycled sources.

With resources centered on the Bushveld complex, South Africa is by far the largest producer of platinum, supplying over 75% of global demand, while Russia (25 tons) and Zimbabwe (7.8 tons) are also major producers. Anglo Platinum (Amplats), Norilsk Nickel and Impala Platinum (Implats) are the largest individual platinum metal producers.

Applications of platinum

For a metal with an annual global production of just 192 tons, platinum is found in critical production of many everyday items.

The largest use, accounting for about 40% of demand, is in the jewelry industry, where it is mainly used in an alloy that produces white gold. It is estimated that over 40% of engagement rings sold in the US contain some platinum. The US, China, Japan and India are the largest markets for platinum jewelry.

Platinum's corrosion resistance and high temperature stability make it ideal as a catalyst in chemical reactions. Catalysts speed up chemical reactions without subjecting themselves to chemical change in the process.

Platinum's main application in this sector, accounting for about 37% of total metal demand, is in automotive catalytic converters. Catalytic converters reduce harmful chemicals from exhaust emissions by initiating reactions that convert more than 90% of hydrocarbons (carbon monoxide and oxides of nitrogen) into other, less harmful compounds.

Platinum is also used to catalyze nitric acid and gasoline; by increasing the octane levels in the fuel.

In the electronics industry, platinum crucibles are used to make semiconductor crystals for lasers, while alloys are used to make magnetic disks for computer hard drives and switch contacts in automotive controls.

Demand in the medical industry is growing as platinum can be used both for its conductive properties in pacemaker electrodes, ear and retinal tissue implants, and anti-cancer properties in drugs (eg carboplatin and cisplatin).

Below is a list of some other platinum applications:

• With rhodium used to make high temperature thermocouples
• To make optically clear, flat glass for televisions, LCDs and monitors
• Making glass threads for fiber optics
• In alloys used to form automotive and aerospace spark plug tips
• As a substitute for gold in electronic compounds
• In coatings for ceramic capacitors in electronic devices
• In high temperature alloys for jet fuel injectors and rocket nose cones
• In dental implants
• To make high quality flutes
• Smoke and carbon monoxide detectors
• For the production of silicones
• In razor covers

Silver - white, density 21.45 g/cm 3 , melting point 1773.5 °C, boiling point - 4410 °C. Harder than gold and silver. Indicated by the symbol Pt. The name comes from the Spanish word plata - "silver"; platina is a diminutive form, literally "little silver" or "silver".

Platinum can be easily processed by pressure (forging, rolling, drawing). Differs in the increased chemical firmness: it is dissolved only in hot "royal vodka", potassium cyanide and the melted alkalis. Separately, none of the acids affects this metal. Platinum does not oxidize in air, even with strong incandescence, and when cooled, it retains its natural color.

Platinum is one of the rarest elements, its average concentration in the earth's crust is 5 10 -7% by weight. It occurs in native form, in the form of alloys and compounds. Until the 18th century, platinum was unknown in Europe. In 1748, the Spanish mathematician and navigator A. de Ulloa was the first to bring samples of native platinum found in Peru to the European continent. The Italian chemist Gilius Scaliger discovered in 1735 that platinum is indecomposable and thus proved that it is an independent chemical element. For the first time, platinum was obtained in pure form from ores by the English chemist W. Wollaston in 1803.

PROPERTIES OF PLATINUM

Physical properties platinum. It crystallizes into face-centered cubic lattices. When salt solutions are exposed to reducing agents, the metal can be obtained in the form of “niello” with high dispersion.

Platinum is able to absorb certain gases on the surface, especially hydrogen and oxygen. The tendency to absorption increases significantly for a metal that is in a finely dispersed and colloidal state. Platinum black strongly absorbs oxygen: 100 volumes of oxygen per volume of platinum black.

Platinum characteristic:
- color grayish-white, shiny;
- atomic radius, nm 0.138;
- crystal lattice parameters at 20 °C, nm a = 0.392;
- density at 20 ° C, kg / dm 3 21.45;
- melting point, °С 1773.5;
- boiling point, °С 4410;
- specific heat capacity, J/(mol/K) 25.9;
- thermal conductivity at 25 °C, W/(m K) 74.1;
- electrical resistivity at 0 °С, μΩ cm 9.85;
- Brinell hardness, MPa 390 - 420;
- modulus of elasticity, GPa 173.

Chemical properties of platinum. Fully reacts only with hot aqua regia:
3Pt + 4HNO 3 + 18HCl = 3H 2 + 4NO + 8H 2 O.
Its dissolution in sulfuric acid heated to a certain temperature and in bromine proceeds extremely slowly.

When heated, it reacts with alkalis and sodium peroxide, halogens (especially in the presence of alkali metal halides):
Pt + 2Cl 2 + 2NaCl \u003d Na 2.

When heated, platinum reacts with oxygen to form volatile oxides. The following platinum oxides have been isolated: black PtO, brown PtO 2 , reddish brown PtO 3 , Pt 2 O 3 and Pt 3 O 4 .

Metallic platinum does not have a toxic effect on the human body, however, the impurities contained in platinum black (primarily tellurium) are poisonous and when they enter gastrointestinal tract there are: necrosis of the gastrointestinal mucosa, granular degeneration of hepatocytes, swelling of the epithelium of the convoluted tubules of the kidney, as well as “general intoxication”.

Healing properties of platinum. Metal nanoparticles are able to freely penetrate directly into the cells of the body and have a positive effect on vital processes. The main function of platinum is considered to be the destruction of free radicals, thus slowing down the process of premature aging. Platinum is also found in some drugs used to treat cancer.

The magical properties of platinum. According to its magical properties, this metal is light and pure, does not carry any evil in itself, does not store, unlike gold, a negative memory. Platinum has a clear connection with the cosmos. The mission of platinum is to bring people goodness and wisdom, enlightenment of the soul and enlightenment of the mind. A product made of platinum should be made a talisman for medical staff, as well as people of those professions where sensitivity to others is central. Jewelery made of rare metal can increase a hundredfold everything positive that is in a person, and neutralize the negative. They will sharpen intuition, show their owner the right path and protect against negative external influences that destroy his energy shell.

HISTORY OF PLATINUM IN RUSSIA

In Russia, platinum was first found in the Urals, in the Verkh-Isetsky district, in 1819. When washing gold-bearing rocks, white shiny grains were noticed in gold, which did not dissolve even in the strongest acids.

In 1823 V.V. Lyubarsky, Berg-assayer of the laboratory of the Petersburg Mining Corps, examined these grains and established that the mysterious "Siberian metal belongs to a special kind of raw platinum containing a significant amount of iridium and osmium."

In 1824, pure platinum placers were discovered in the Urals. These deposits were exceptionally rich and immediately brought Russia to the first place in the world in the extraction of platinum.

In 1826, an outstanding engineer of his time, P.G. Sobolevsky together with V.V. Lyubarsky developed a simple and reliable method for obtaining malleable platinum.

On March 21, 1827, in the conference hall of the St. Petersburg Mining Cadet Corps, at a crowded solemn meeting of the Scientific Committee for the Mining and Salt Part, the first products made from Russian platinum made by the new method were shown - wire, bowls, crucibles, medals, an ingot weighing 6 pounds.

Since 1828, platinum coins of 3, 6, and 12 ruble denominations began to be issued in Russia.

In 1843, 3500 kg of platinum was already mined. This affected the price, platinum became cheaper.

In 1845, by special decree, due to the fear of counterfeiting and importation of platinum coins from abroad, all platinum coins were withdrawn from circulation within six months.

In 1867, a royal decree abolished the state monopoly on platinum and permitted its duty-free export abroad. Taking advantage of the favorable market conditions, England bought up all the reserves of this metal - more than 16 tons.

Before the First World War, platinum production in Russia was 90...95% of the world production.

In May 1918, the Institute for the Study of Platinum was established, which later merged into the Institute of General and Inorganic Chemistry of the USSR Academy of Sciences, now named after Academician N.S. Kurnakov.

Platinum mining

Pure platinum is very rare in nature. The main form of its presence in the ore is its own minerals, of which about 90 are known. The polyxene mineral contains 80 ... 88% Pt and 9 ... 10% Fe; cuproplatin - 65...73% Pt, 12...17% Fe and 7.7...14% Cu; Nickel platinum also includes iron, copper and nickel. Known natural alloys of platinum only with palladium or only with iridium. There are also a few minerals - compounds of platinum with sulfur, arsenic, antimony.

Industrial use is technically possible and economically feasible if the ores contain platinum metals:
- in indigenous deposits from 2 - 5 g / t to units of kg / t;
- in indigenous complex - from tenths to hundreds (occasionally thousands) g/t;
- in alluvial deposits - from tens of mg/m 3 to hundreds of g/m 3 .
Significant accumulations of ore in the form of deposits are very rare.

Ore is mined by open and underground methods. The majority of alluvial deposits and part of primary deposits are developed by the open method. The underground mining method is the main one in the development of primary deposits; sometimes it is used to mine rich buried placers.

After wet enrichment of the ore, a "raw" concentrate is obtained - a concentrate with 70 - 90% of metal minerals. This concentrate is sent for refining. Enrichment of complex sulfide ores is carried out by flotation followed by multi-operational pyrometallurgical and electrochemical processing.

The main part of platinum deposits (more than 90%) lies in the bowels of five countries. These include South Africa, USA, Russia, Zimbabwe, China.

In 2008, 200 tons of platinum were mined in the world. The leaders in production were: South Africa - 153.0 tons, Russia - 25.0 tons, Canada - 7.2 tons, Zimbabwe - 5.6 tons, USA - 3.7 tons, Colombia - 1.7 tons.

The leader in platinum mining in Russia is MMC Norilsk Nickel. The largest platinum nuggets displayed at the exhibition of the USSR Diamond Fund weigh 5918.4 and 7860.5 grams.

The explored world reserves of platinum group metals are about 80,000 tons and are distributed mainly between South Africa (87.5%), Russia (8.3%) and the USA (2.5%).

Platinum production

From the mines, raw platinum goes to the refinery. Here it is subjected to prolonged heating in porcelain cauldrons with aqua regia. As a result, almost all platinum and palladium, partly rhodium, iridium, ruthenium and the bulk of base metals go into solution.

Platinum in solution is in the form of two complexes:
H 2 - most of and
(NO) 2 .
By adding HCl to the solution, the (NO) 2 complex is destroyed so that all the platinum is converted to the H 2 complex.

Further, the iridium, palladium, rhodium present in the solution is converted into compounds that are not precipitated by ammonium chloride, and then the solution is “adjusted” by heating it with acids (sulfuric or oxalic) or (according to the Chernyaev method) with a sugar solution.

Now you can enter ammonia and precipitate platinum in the form of ammonium chloroplatinate. A solution of ammonium chloride is administered in the cold. In this case, the main part of platinum in the form of small bright yellow crystals (NH 4) 2 precipitates. The precipitate is further cleaned with a solution of ammonia and dried. The dry residue is placed in an oven. After several hours of calcination at 800...1000°C, spongy platinum is obtained in the form of a sintered steel-gray powder.

The resulting sponge is crushed and washed again with hydrochloric acid and water. Then it is melted in an oxy-hydrogen flame or in a high-frequency furnace. This is how platinum bars are obtained.

When platinum is mined from sulfide copper-nickel ores, in which its content does not exceed a few grams per ton of ore, platinum and its analogues are sourced from the sludge of copper and nickel electrolysis shops. Sludge is enriched by roasting, secondary electrolysis, and other methods. In the resulting concentrates, the content of platinum and its eternal companions - platinoids - reaches 60%, and they can be extracted from concentrates in the same way as from raw platinum.

APPLICATION OF PLATINUM

Over the past 20...25 years, the demand for platinum has increased several times and continues to grow. Before World War II, over 50% of platinum was used in jewelry. Now about 90% of the consumed platinum is used in industry and science. The use of platinum in medicine is also growing.

Acid-resistance, heat-resistance and constancy of properties upon ignition have made platinum absolutely indispensable in the production of laboratory equipment. From platinum they make: crucibles, cups, glasses, spoons, spatulas, spatulas, tips, filters, electrodes. Platinum glassware is used for particularly precise and responsible analytical operations.

The use of platinum in technology

The most important areas of application of platinum were the chemical and oil refining industries. About half of all platinum consumed is now used as catalysts for various reactions.

Platinum is the best catalyst for the oxidation of ammonia to nitric oxide NO in one of the main processes for the production of nitric acid.

Platinum catalysts are used in the synthesis of vitamins and some pharmaceuticals.

Platinum catalysts accelerate many other practically important reactions: hydrogenation of fats, cyclic and aromatic hydrocarbons, olefins, aldehydes, acetylene, ketones, oxidation of SO 2 to SO 3 in sulfuric acid production.

Using platinum catalysts, catalytic reforming units produce high-octane gasoline, aromatic hydrocarbons and technical hydrogen from gasoline and naphtha oil fractions.

The automotive industry uses the catalytic properties of this metal - for afterburning and neutralization of exhaust gases.

Platinum is indispensable for modern electrical engineering, automation and telemechanics, radio engineering and precision instrumentation. It is used to make fuel cell electrodes.

An alloy of platinum and rhodium is used to make spinnerets for the production of glass fiber.

Platinum and its alloys serve as an excellent corrosion-resistant material in chemical engineering. Equipment for the production of many highly pure substances and various fluorine-containing compounds is coated with platinum from the inside, and sometimes entirely made of it.

Platinum and its alloys are also used to make:
- special mirrors for laser technology;
- heating elements of resistance furnaces;
- anode rods for corrosion protection of submarine hulls;
- insoluble anodes in electroplating;
- electroplated coatings;
- permanent magnets with high coercive force and residual magnetization (platinum alloy - cobalt PlK-78).
- electrodes for the production of perchlorates, perborates, percarbonates, peroxysulphuric acid (in fact, the use of platinum determines the entire world production of hydrogen peroxide).

The use of platinum in medicine

A small part of platinum goes to the medical industry. Surgical instruments are made from platinum and its alloys, which, without oxidizing, are sterilized in the flame of an alcohol burner. Alloys of platinum with palladium, silver, copper, zinc, nickel serve as an excellent material for dentures.

The inertness of platinum to any compounds, its electrical conductivity and non-allergenicity make it possible to actively use it in biomedicine as a component of electrical stimulators, catheters and other medical equipment.

Certain platinum complexes are used in chemotherapy and show good antitumor activity for a small number of tumors.

The use of platinum in jewelry

Every year, the world jewelry industry consumes about 50 tons of platinum. Most platinum jewelry items in the trade contain 95% pure platinum. It has a minimum of impurities, so it is so pure that it does not fade, does not change color and retains its shine for many years.

The brilliant brilliance of platinum best reflects the true brilliance of diamonds and is the perfect setting for precious stones and combined with natural yellow shades of gold. Due to its purity, it does not irritate the skin, since, unlike some other metals, it does not contain allergenic impurities.

The most important feature of platinum is durability. Silver and gold jewelry can wear out and have to be sent in for repairs to replace the worn part with new metal. Products made of platinum do not wear out, they are practically timeless.

INVESTING IN PLATINUM

The rarity of platinum and the high demand for it make this metal an attractive investment. Investing in platinum is a powerful financial instrument that, if used skillfully, can significantly increase your capital. This is an expensive status metal, which is widely used in industry. It is the growing demand for platinum that is the main reason for the steady growth in its prices.

Platinum is a commodity: it trades on the London Metal Exchange and the New York Stock Exchange. In addition to platinum with immediate delivery, there are futures contracts. Prices are in troy ounces.

Platinum in terms of investment is a definite alternative to savings in a particular currency. In Russia, investing in precious metals, including platinum, is offered to its clients by a number of banks - Sberbank, NOMOS-Bank, SMP Bank, etc. It is possible to make transactions with physical ingots and using depersonalized metal accounts. In order to carry out such operations for their clients, banks under Russian law require a special license.

Graph of platinum price changes during 2013. The price of platinum in rubles per gram is calculated daily by the Central Bank of Russia.

Opening of depersonalized metal accounts (OMS).

OMS can be opened both by depositing physical metal (ingots) into this account, and by purchasing depersonalized metal from a bank for cash rubles or by debiting funds from a current account or a deposit account. Based on the period of functioning of the CHI, there are current and deposit accounts.

CHI on demand (current). Income is formed based on the growth of the market value of the precious metal in the account. The depositor can both withdraw funds and replenish the account. With this option, he has the opportunity to maneuver and manage his income, but this requires certain analytical skills.

OMS urgent (deposit). The term of savings savings on deposit MHI is fixed, it is negotiated when opening an account and varies from bank to bank. Income is generated from interest that is accrued in grams of the precious metal and the dynamics of precious metals quotations on world markets over this period. It may turn out that during the expiration of the contract, market prices will change in an unfavorable direction, and this may bring you losses.

Banks collect commission fees from customers for certain operations on the account, namely:
- for crediting the precious metal to the account upon the physical delivery of ingots;
- for the issuance of precious metal from an unallocated metal account in physical form;
- income received from changes in precious metal quotes is subject to personal income tax at a rate of 13%, the responsibility for declaring and paying tax lies with the investor.

The most serious drawback of this investment instrument and at the same time the biggest risk for the investor is the lack of compulsory compulsory health insurance. This fact requires especially careful selection of a bank for conducting compulsory medical insurance.

Buying precious coins.

The tax legislation of the Russian Federation classifies platinum coins of the Russian Federation and the USSR as commemorative, therefore, when buying these coins, you must pay VAT, which will be 18% of the value of the coin. Income from investments in precious coins is calculated as the difference between the price of the initial purchase of coins from the bank and the price of their subsequent sale to the bank.

In the Soviet Union, commemorative commemorative platinum coins were issued from 1977 to 1991. In Russia, platinum coins were issued from 1992 to 1996. Platinum coins are also issued by other states.

It is worth noting that platinum coins are very rare, they are quite difficult to find on sale, not to mention the possibility of their resale in a bank branch.

Purchase of measured bars.

The largest banks in Russia develop and approve their own rules for the sale and purchase of measured bars. These rules describe in more detail the requirements for the compliance of measured bars with standards for the admissibility of their contamination, as well as the cleanliness and integrity of the documentation accompanying them. Before buying bullion, you must carefully study these rules.

If you do not plan to take out an ingot purchased from a bank from a certified vault, but wish to transfer it for storage to the same bank by issuing a metal deposit account, then the legislation allows you not to pay the amount of VAT from the purchase.

Many experts believe that platinum is just the investment tool that you can trust and having 10 - 15% platinum in your investment portfolio of precious metals will not be superfluous at all. But only the investor himself decides whether this type of precious metal can be useful to him or not.

In ores, platinum and gold often accompany each other. However, the gold miners of the past, when smelting gold, simply threw away pieces of nondescript metal. Together with gold and silver, platinum did not melt; under the hammer on the anvil it became harder; in appearance it slightly resembled silver - but dirty, worthless ...

In a word, an unnecessary impurity went to waste. And yes, there was quite a bit of it! So little that European noble metal casters did not even suspect the existence of platinum as a separate element of the Universe until the middle of the ΧVΙΙΙ century. Unlike the Incas...

The intricate history of the precious metal

Atomized stellar substance condenses into dust. Gravitational fluctuations form more or less massive lumps of matter. In different ways, interstellar matter, some of which is noble metals, gets to the surface of the planets. Where it dissipates in the thickness of the crust ...

The processes of erosional destruction of the planet's bedrocks with the re-formation of sedimentary and metamorphic layers allow heavy metals to concentrate in deposits. Rare and not numerous - if we talk about platinum and platinum group metals.

Platinum and platinoids on Earth

Explored reserves of platinum are estimated at 80,000 tons, with the main deposits located on the territory of five states. South Africa and Zimbabwe, Russia and China, and the United States contain about nine-tenths of the world's platinum reserves. Canada, South America and other countries own small deposits.

However, there are estimates that allow 90% of crude platinum to be attributed to South African mines. Which, of course, indicates not so much the exclusivity of South Africa, but the insufficiency of geological exploration of the bowels of the rest of the Earth.

Natural compounds of platinum

Particularly large platinum nuggets have not been found in nature. Not very impressive in appearance, platinum nuggets weighing 5918 g and 7860 g are stored in the Diamond Background of Russia. They were found in the alluvial deposits of Konder (Khabarovsk Territory) and Isovsky mine (Urals).

History of the development of wealth

The Spaniards, who contemptuously called the new metal “silver”, figured out how to fake gold with the help of platinum. It is very profitable to take platinum at a bargain price (half the price of silver) and add it to a gold alloy. Mixed with gold in relatively small amounts, platinum does not change the color of the alloy. But it allows you to save expensive material!

That is why the Spanish authorities ordered to drown platinum: partly directly in Colombia, partly already in Spain. And they drowned until the Madrid court itself decided to earn extra money by counterfeiting. Looking at the tricks of those in power, naturalists became interested in the new metal, and, after conducting a series of research experiments, first in 1750, and again in 1803, they isolated pure platinum from scattered samples.

It took another 30 years for Julius Scaliger, a chemist from Italy, to provide irrefutable evidence: platinum is a chemical element, and not dirty gold or silver spoiled with impurities. However, Scaliger had predecessors who claimed the same thing 80 years before him - but the science of those years was not very hasty. In fact, recognition of platinum came only in the ΧΙΧ century.

The English engineer William Wollaston (discoverer of rhodium and palladium) suggested making vessels from platinum for the production of concentrated acids. The offer turned out to be sensible, and the demand for the metal increased.

Russia, which at that time had relatively rich deposits of platinum, began minting coins from it ten years after the start of mining the precious metal. There was no practical use for the precious metal in Russia for a long time, and all supplies (more than 16 tons of refined platinum) were sold to England in 1867.

As it happened both before and later, and not only with the Russian rulers, they simply did not consider the potential of their “titmouse in their hands”.

Physical and chemical properties of platinum

Platinum is chemically stable, but reacts with hot aqua regia. Dissolves in bromine. When heated, it reacts with a few metals and non-metals. Dissolves molecular hydrogen. Known as an active catalyst for the processes of oxidation and addition of hydrogen. In particular, spongy platinum is capable of provoking the ignition of a mixture of hydrogen and oxygen at low gas temperatures. Before the invention of matches, lighters using this principle were widely produced.

Application of platinum

Until recently, Japan (now replaced by China) remained the main consumer of platinum jewelry: there, platinum rings are as common as gold jewelry. In China, up to 25 tons of jewelry made of platinum are sold annually.

Growth in demand for jewelry platinum and platinum group metals is also observed in Europe. However, platinum jewelry is not popular in Russia: only 0.1% of the world's platinum jewelry is sold in Russia.

The lion's share (at least 90%) of the mined metal goes into industry. Platinum is used to produce devices for the chemical industry: laboratory glassware and equipment, filters, electrodes. At least half of technical platinum is used for the production of all kinds of catalysts, including automotive ones.

Not without platinum and electrical engineering, and glass production. Platinum or platinum contacts are not afraid of discharge arcs. Platinum dies are used to make fiberglass.

The space industry without the stability of platinum as an electrically conductive, corrosion-resistant and heat-resistant material would hardly have reached today's heights. One of the mass standards is made of an alloy of platinum and iridium: it is a cylinder 39 mm high and also 39 mm in diameter.

Platinum is also used as a bank metal: the cost of platinum is consistently high, the price increase is constant; as an investment object, this noble metal is very profitable!

Unused in the past, today platinum is in demand more than ever. And if humanity either wants to or does not want to send space tractors for hypothetical golden asteroids, then an expedition will be equipped for a celestial body made of platinum without hesitation: the unique properties of the noble metal are so useful.

Indicated by the sign Pt.

History of platinum

The ancient world already knew the metal platinum. During archaeological excavations in Egypt, in the ruins of ancient Thebes, an artistic case was found, attributed by experts to the 7th century BC. BC e. This relic of the ancient world contained a grain of iridium-rich platinum.

At the beginning of the 1st century n. e. gold-sand panners in Spain and Portugal began to show a marked interest in the beneficial use of "white lead", or "white gold", as platinum was then called. According to the Roman writer Pliny the Elder (author of the 37-volume book "Natural History"), "white lead" was mined from the gold placers of Valissia (Northwestern Spain) and Lusitania (Portugal). Pliny tells that the "white lead" was collected during washing along with gold at the bottom of the baskets and melted separately.

Long before the capture of South America by the Spanish and Portuguese conquistadors, platinum was mined by the cultural native people - the Incas, who not only owned the secret of cleaning and forging this precious metal, but also knew how to skillfully make various objects and jewelry from it.

The era of the fall of the Roman Empire is marked by the disappearance of jewelers and platinum jewelry dealers. Many centuries passed, and only in the second half of the XVIII century. platinum and its physical chemical properties scientists began to take an interest.

In 1735, the Spanish mathematician Antonio de Ulloa, while in Equatorial Colombia, drew attention to the frequent presence, together with gold, of an unknown metal, the brilliance of which somewhat resembled the brilliance of silver, but in all other qualities more like gold. This outlandish metal interested de Ulloa, and he brought samples of Colombian platinum to Spain.

In the 18th century, when platinum did not yet have an industrial use, it was mixed with gold and with gold and silver products. The Spanish government learned about this "damage" to precious metals. Fearing the possibility of mass forgery of the gold coin, it decided to destroy all platinum mined together with gold in the kingdom's colonial possessions. In 1735, a decree was issued ordering the destruction of all platinum mined in Colombia. This decree was in effect for several decades. Special officials, in the presence of witnesses, periodically threw cash stocks of platinum into the river.

At the end of the XVIII century. the Spanish kings themselves began to "spoil" the gold coin, mixing platinum with it.

Technical uses of platinum

In 1752, the director of the Swedish mint, Schaeffer, announced the discovery of a new chemical element - platinum. Companions of platinum - palladium, iridium, rhodium, ruthenium and osmium - were discovered much later, in the 19th century. The six listed chemical elements, which are in the eighth group of the periodic system of Mendeleev, make up a group called platinum metals. All these metals have many similar physical and chemical properties and are mostly found together in nature.

At the dawn of the introduction of platinum into technology, scientists dealt with it mostly out of curiosity, but as the properties of platinum were studied in depth, it quickly began to find wide application, especially in the chemical industry. It turned out that platinum is soluble only in aqua regia, insoluble in acids and constant when heated.

Following the appearance of the first samples of chemical glassware made of platinum, it began to be used for the manufacture of distillation apparatus for sulfuric acid. From that moment on, the growth of platinum processing began to increase sharply, since it began to be used in the production of acid-resistant and heat-resistant laboratory chemical equipment, tools and various devices (crucibles, flasks, boilers, tongs, etc.).

Pyrometry uses the exceptional resistance of platinum and its alloys to high temperatures.

Valuable and sometimes indispensable properties of platinum and palladium have long been used in catalytic processes. A significant amount of platinum is spent on the manufacture of contacts for sulfuric acid plants, where it serves as a catalyst in the oxidation of sulfur dioxide to sulfuric anhydride. Platinum in the form of a grid serves as a catalyst for the oxidation of ammonia in apparatuses of various systems. Numerous organic syntheses also require the use of a platinum catalyst. The palladium catalyst is used in the production of synthetic ammonia and in the production of some organic preparations. Osmium is also used in the production of synthetic ammonia according to Haber-Rosennel.

In electrical engineering, platinum metals are usually used in the form of alloys. That's far from full list parts of electric devices where platinum alloys are used: needles for burning, devices for electrical measurements, electrodes (cathodes and anticathodes for X-ray tubes), wires and tapes for the resistance of electric furnaces, magneto contacts (cars, internal combustion engines), contact points (telegraphy, telephony), lightning rod tips, etc.

In electrochemistry, platinum is used in the production of various electrolytic products. Medicine and dentistry are among the oldest consumers of platinum. We also note the use of platinum for surgery in the form of tips for devices used for cauterization, syringes for injection and infusion, etc.

The art of jewelery occupies a leading position as a consumer of platinum in the form of alloys. Platinum gemstone settings give better brilliance and cleaner water than other precious metal settings.

Finally, in the form of salts, platinum and its companions are required for photography, for the manufacture of medicines (salts of rhodium and ruthenium) and for the preparation of paints on porcelain (rhodium, iridium - black paint, palladium - silver).

Platinum is also used in the military, for example, for the manufacture of contacts that serve to produce detonation during the explosion of mines, etc.

Platinum mining

The first place in the world production of platinum belongs to the Ontario region in Canada. Here, in 1856, large deposits of copper-nickel ores of Sudbury were discovered, in which, along with gold and silver, platinum is also present.

Before the First World War, Canadian platinum did not attract attention, and practical interest in it arose only in 1919, when, as a result of the civil war in the Urals, the extraction of Russian platinum fell sharply, and the world market began to feel a great shortage of this valuable metal. Since 1919, the sludge from the copper-nickel production of Sudbury began to be subjected to thorough processing in order to extract platinum group metals, especially since the cost of associated mining of platinum and its satellites is very low.

Russia occupies the second place in the world in platinum mining. Significant amounts of platinum are mined in Colombia. Other platinum-producing countries include Ethiopia and the Congo. Platinum mined directly from the depths, as well as platinum obtained from ores, is subjected to special processing or refining. Refining consists of the usual processes used on a small scale in the practice of analytical laboratories - dissolution, evaporation, filtration, precipitation, etc. As a result of these operations, pure platinum and separately its satellites are obtained.

Platinum deposits in Russia

The main platinum-bearing province of the Urals is the western zone of deep igneous rocks, continuously traced for 300 km in the region of the Middle Urals. Platinum deposits in this zone are associated mainly with igneous rocks. During the weathering and destruction of these rocks and when the weathering products are washed away by rivers, pure platinum placers are formed, which are an exceptional feature of the Urals and have provided the bulk of the platinum mined so far.

In the region of the eastern zone of deep igneous rocks there are a number of less valuable deposits of platinum. Here platinum occurs together with gold and osmium iridium. Due to the destruction and erosion of these rocks, mixed gold-platinum and gold-osmite-iridium-platinum placers are formed, which are less valuable from the point of view of the extraction of platinum, which is here only an admixture to gold.

Ural platinum before the war of 1914-1918. ranked first in the world market. In the first half of the XIX century. (from 1828 to 1839) a coin was minted from Ural platinum in Russia. However, the minting of such a coin was discontinued due to the instability of the exchange rate for platinum and the importation of counterfeit coins into Russia.

Despite the fact that in Russia platinum refining began immediately after the discovery of platinum deposits in the Urals. before the revolution, the amount of platinum processed in our country was only 10-13% of the mined metal. Most of the crude platinum and refining intermediates were exported abroad.

There has been a refinery in Moscow for more than 100 years, where they are engaged in the mechanical processing of refined platinum and alloys. It also produces forging, rolling, wire drawing, manufacturing of chemical glassware, grids of electrodes, contacts, pyrometers, electric heaters and other products.

Among all noble metals, platinum occupies a special place and its value 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 not common. The higher cost of Platinum is at least due to the fact that about 10 tons of rock have to be processed to obtain one ounce. In turn, to create a similar amount of gold, about 3 tons of ore is spent.

History of metal

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. The latest history of mining and processing of platinum dates back to the period of the development of America by the Spanish conquistadors.

However, at first, due attention was not paid to the metal, as evidenced even by its name - in Spanish, the word means “little silver”. Often it was considered unripe gold at all and was thrown away. It's a pretty tough metal., which has a high density index, which significantly complicates its processing.

Among the properties of the metal, it is worth noting the most unique:

• 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 plasticity and well gives in 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.

The metal in its pure form is practically not found in nature, and if we talk about what platinum consists of, then most often it is alloys with rhodium, palladium, iron, iridium and some other substances.

The rate of oxidation depends on the pressure of oxygen and the rate of its supply to the metal surface. Since most often it is mined in the form of alloys, the presence of other substances in them slows down this process.

The most common oxides are:

The resistivity of platinum is relatively small, but in terms of electrical conductivity, it is inferior to aluminum, silver, and copper. At the same time, during heating, the resistivity index increases, and the conductivity decreases accordingly. Scientists explain this fact by the fact that as the temperature increases, the particles that make up platinum begin to move randomly 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. Cisplastin was the first such drug, but oxaliplatin and carboplatin are currently 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:

From about the middle of the XVIII century in Russia, platinum performed a monetary function. Exactly the first platinum coins were made in the Russian Empire, but 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.