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Sergey Venezky
STORIES ON METALS

PLATINUM:

FOR THREE LOCKS

Find the conquistadors. - The decree of the Spanish king. - Again in Europe. - Close relatives. - The first in Russia. - "Diamond" steel. - Assault on the fortress. - Oversight of the Minister of Finance. - In fond memory. - The treasure in the waste. - Winner of the Demidov prize. - In gram production. - Warm welcome. - The sparks are extinguished in the wind? - With great speed. - It was in the Donbas. - In the terrible year. - Transparent mirror. - The Gift Of Montezuma. - Measure the temperature. - Three keys. - Alignment on the platinum. - "For all times, for all peoples." - Orange rays. - Platinum diagnoses. - Not feeling any pain. - Modest beach attire. - A high honor.

In the XVI and XVII centuries the Spanish conquistadors unceremoniously they plundered the wealth of the ancient States of the Aztecs and the Incas. Tons of gold, silver, emeralds filled the holds of Galleons, which are constantly shuttled between America and Spain. Once the invaders, driving along the river Platinum del Pinto (Colombia), found on its banks gold and nuggets unknown to them heavy silver metal.  Conquistadors believed platinum useless metal....due to the high refractoriness he was not suitable and only complicated the purification of gold. New metal Spaniards decided to call platinum, which means "cerebrate (serebristo", "bad silver"), thereby expressing their bad attitude.

Still a pretty large number of platinum were taken to Spain, where it was sold at a price significantly lower than silver. Soon the Spanish goldsmiths discovered that platinum is a well-alloyed with gold, and those who were not pure in his hand, began to admix it to gold in the manufacture of jewelry and fake coins. About these "tricks" jewelers became known to the king, and he found nothing better than to issue a decree requiring to stop the importation of worthless metal, and at the same time and destroy all his reserves to the Scam-jewelers could no longer fooling honest people.

Officials of the Royal mints gathered all available in Spain and its colonies platinum, have received by this time such unflattering nicknames like "rotten gold", "frog gold, and publicly gave this metal "penalty" because of his "deceitful entity: collected platinum drowned in the sea and rivers, where deeper. In the future, such an operation was repeated again and again. So sad it ended the first stage in the biography of platinum.

In the mid-eighteenth century in Spain was published two-volume work of the Navigator, astronomer and mathematician Antonio de Ulloa "Journey to South America". Being there in the expedition, the scientist became interested in native platinum, brought her to Europe and described in his book, after which disgraced the metal has attracted the attention of many European scientists.

A detailed study of the platinum held by the Swedish chemist Heinrich Schaeffer, who proved that it is not a mixture of known metals (such as gold and iron), as asserted by some scholars as a new chemical element.

The study of platinum led to the discovery of several metals that accompany it in nature and have received the General name platinum: in 1803 were discovered palladium and rhodium, in 1804 - osmium and iridium, and forty years later chemists became known and the last element of this group is ruthenium.

Work in this area was largely facilitated by the fact that in 1819, in the Urals, near Ekaterinburg (now Sverdlovsk) geologists have discovered alluvial deposits of platinum. After five years in these parts began to act first in Russia platinum mine. The wealth of the Urals placers says fun fact: in those days, local hunters have beaten the game a fraction of platinum.

About the same time the metal began to be used as an additive to steel. "6 pounds of steel were melted with 8 spools purified platinum agapostemon clay pot, protecting the metal from air access, wrote in 1825, "Mining magazine". - Molten mass was poured in a cast-iron form and soon chilled in cold water. Upon fracture of the steel bar steel was very homogeneous rashes and so small that ordinary eyes could not be seen grainy her addition. Being machined and tempered, without leave, she cut glass like a diamond, chopped cast iron and not protoplast... Generally platanista steel is much harder than any hitherto known, and can withstand most bumps and don't break". For extremely high hardness of this steel is called "diamond". In this role, platinum was made quite a long time, but then was forced to give up her seat less expensive and also more able to tungsten.

Important page in the biography of platinum wrote the famous Russian engineer and scientist, P. Sobolewski. Head of the St. Petersburg Joined the laboratory of Department of mining and salt Affairs, Mining cadet corps and the Main mountain pharmacy, he along with his associate Metallurgist centuries Lubarsky began to study raw platinum and the development of the technology of converting it into a malleable metal. The thing of it was that none of the existing furnaces could not be heated platinum before its melting point equal to 1769°C, or at least close to it temperature. But it was a necessary condition without which platinum had refused to accept one or another desired shape. Yes, it was something to smash his head.

If the fortress is unable to master the storm, we have to look for other ways. So did the researchers. They filled spongy platinum (such porous metal was obtained by chemical processing of ores) specially-made metal form, compressed it to a screw press, heated to a white heat, and then again subjected to a large pressure. And metal surrendered, after melting, spongy platinum turned into solid products, which could not be distinguished from the cast. So in 1826 for the first time in the history of technology was created and implemented original technological process that has retained its value to this day: it lies at the basis of modern methods of powder metallurgy.

Merits of Sobolev were awarded by the Minister of Finance E. F. Cancrini. He offered to produce annually scientist "model reward" for 2500 rubles in excess of the salary, "how long in the service abides". The king approved the proposal of the Minister.

At the same time Sobolevskoe was instructed to start chasing 3-, 6 - and 12-ruble platinum coins. Soon St. Petersburg Mint started in full swing to release the money. In a relatively short period of time was released almost half a million platinum coins, for that matter about 15 tons of platinum. However, the price of this metal has grown, as they say, not by days but by hours, and the government realized that I had made a mistake: platinum money became more and more expensive, with the result that their true value significantly exceeded the nominal and soon they are effectively out of circulation. This, on the one hand, contributed to the measures taken by the Ministry of Finance with the aim of returning platinum in the Treasury, and on the other hand, the initiative of individuals who chose to pay other money, leave the platinum itself "good memory". Now these coins are very rare and they can be seen only in very few major numismatic collections.

The production of platinum coins suddenly had the benefit of science. In the laboratory Mint has accumulated quite a lot of residue platinum ore - waste from the production of coins. In 1841 Professor of chemistry at Kazan University Karl Karlovich Klaus asked the Mint to send him to study a few pounds of these residues. The request was granted, and the scientist started to analysis, it would seem that no suitable waste. To his surprise, he found them in up to 10% of platinum and a small amount of osmium, iridium, palladium and rhodium.

Anyone not worried residues immediately became in fact the richest treasure. Klaus immediately reported the results obtained in the Mining Department. Some time later, the scientist arrived in St. Petersburg, where he was received by the Earl of Kankrin. The careful attitude to the message of chemist and gave him assistance in obtaining platinum residues for further research.

Hard work Claus was a success: he was able to prove that among all the known elements of the platinum residues contain a new metal, which the scientist in honor of our country gave the name "ruthenium" (from the Latin name of Russia). For this discovery, Klaus received a full Demidov prize, presidencyza the Russian Academy of Sciences.

Platinum mining in the Urals grew rapidly. It is significant that in the early XX century Russia accounted for about 95% of the total number of platinum mined in the world (the other 5% made in Colombia. Further on the world market started to go platinum from South Africa, Canada.

Characteristically, if the annual world production of gold well over a thousand tons, production of platinum and now amounts to only tens of tons. This is not surprising: the words of the poet "in gram production in year works" can be rightfully attributed to platinum. Indeed, to obtain the grams of this metal, it is necessary sometimes to process hundreds of cubic meters of ore at a railway carriage. This is due to the extreme poverty platinum ores and lack of large deposits of platinum. In the native state, it is extremely rare. The largest ever found nuggets of platinum weighed less than 10 pounds .

The practical application of this metal is found in the beginning of the last century, when someone came up with a good idea to make a retort for the storage of concentrated sulfuric acid. Since then, the extremely high resistance of platinum with respect to acids it provides a warm welcome in chemical laboratories, where she serves as a material for crucibles, bowl, nets, tubes and other laboratory attributes. A large number of platinum also spent on the production of acid and heat-resistant equipment of chemical plants.

Despite the fact that platinum screw to mix the molten glass on the famous glass factories of Czechoslovakia, is three quarters of a million kroons, as a platinum crucible, where this process twice more, the game is worth the candle: this equipment is the most modern, allowing to obtain high-quality glass for microscopes, binoculars and other optical devices.

Chemists have found platinum another important use: it was the most active catalyst for many chemical processes. This ability platinum allowed Hungarian inventors to create newly lighter new type: it has no traditional gear wheel; no chert. Is to remove the cap immediately flame appears: leaving lighters gas erupts from contact with air. But this reaction proceeds only in the presence of a catalyst. Its the platinum ring, through which the gas flows. This lighter is not afraid of wind. Moreover, the stronger it is, the more energetic the reaction, the longer the flame. Once the ring is closed by a cap, the flame goes out.

As a catalyst of platinum absolutely necessary for the oxidation of ammonia with nitric acid. The mixture of ammonia and air at high speed blow through a thin platinum mesh (with up to five thousand holes per square centimeter), oxides of nitrogen and water vapor. When dissolved nitrous oxide in water and turns into nitric acid.

In practice factory nitric acid production went platinum thanks to the work of the pioneer domestic azotnokislogo industry A.I. Andreev, for a long time studying the influence of various catalysts on the oxidation of ammonia. It happened in the first world war, when the demand for nitric acid required for the production of explosives, has increased dramatically. Why: because for every kilogram of explosives spent more than two pounds of nitric acid. By the end of 1916 the monthly demand of the Russian army in explosives was about 6,400 tons. Natural raw material for production of nitric acid was present only in Chile, so all participated in the war of the country, experiencing acute nitric acid starvation, frantically searching for his way of solace.

Then Andreev and proposed to use as the required raw materials ammonia contained in the waste production of coke. His study convinced him high catalytic ability of platinum and that in her presence the ammonia is oxidized very vigorously. On the proposal and the project Andreev in the Donbas, where were concentrated by-product coke plants, and consequently, that there is sufficient ammonia, began building a plant for the production of nitric acid. In the summer of 1917 he has already given its first products - isotonicity problem was successfully solved.

About enormous value, which by this time was given to platinum, can be judged by the following fact: in Grozny for our country 1918 in Russia was organized by a special Institute for the study of this metal which later became a part of the Institute of General and inorganic chemistry of the Academy of Sciences of the USSR. There still is a lot of research work related to chemistry and technology of the platinum group elements.

In platinum today need not only chemists. Ability to vaivase in the glass makes it an important material for the manufacture of many glass devices.

Causing thin layer of metal on the glass, get the platinum mirror, has an interesting property - the so-called one-way transparency: from the light source mirror is opaque and reflects before him items, like an ordinary mirror. But the shadow side is transparent, like glass, and thus, you can see everything that is on the other side. Platinum mirror received at one time widespread in the United States. They were inserted instead of the glass in the Windows of the lower floors of various offices and institutions and in homes they successfully replaced the curtains.

 Montezuma sent several mirrors in the gift of the king of Spain.by the Way, the first platinum mirror, but not glass, and "metal", was a well-crafted and highly polished sheet of platinum, made by the ancient Aztecs. As they did, is still a mystery: in fact, platinum is a well-forged only when a white heat, i.e. at a very high temperature, is not available in the metallurgy of the time. But, be that as it may, the famous Aztec leader Montezuma sent several such mirrors as a gift to the king of Spain. Monarch did not remain in debt": at 1520 Montezuma was captured by the conquistadors, and then executed.

Property spongy platinum to absorb large volumes of gas underlies an amazing phenomenon: the hydrogen or oxygen, enclosed in a hermetically sealed in a platinum vessel, when heated "derived" from it, because the gas molecules pass through the platinum of the vessel wall, as water through a sieve.

Productively platinum and in the field of measuring high temperatures. In the technique widely used platinum resistance thermometers. The principle of their action is based on the fact that when heated electrical resistance of platinum increases very strict and constant dependence on temperature. Connected to the device, the nonvolatile resistance change, a platinum wire without delay signals him on the minor temperature fluctuations.

Even more common are the so-called thermocouple is a simple but very sensitive thermostatically devices. If you solder two wires of different metals, and then to heat the place of junction, the chain appears to electric current. The higher the temperature, the greater the electromotive force occurs in the circuit of the thermocouple. To fabricate these devices often use platinum and its alloy with rhodium or iridium.

Together with iridium platinum for quite a long time the group performs behalf of the society. In Leningrad on Moskovsky prospect is outwardly unremarkable building, at the entrance to which is hung black plates, where in two languages - Russian and French - written: "the State standards of the USSR". This is one of the buildings of the all-Union scientific research Institute of Metrology named DI Mendeleev. Here in the safe behind the thick doors kept the prototype kilogram, made in 1883 from an alloy of platinum (90%) with iridium (10%).

To enter this safe, where support is strictly constant temperature and humidity, it is possible only in the presence of three people: the Director of the Institute, the scientific Keeper of the national standards and the scientific Keeper of this standard. Each of them has the key from only one of the three locks of the safe. Massive door opens only when the locks are inserted all three keys. The benchmark represents the cylinder height and diameter of 39 mm , and rests on a stand made of rock crystal under two glass covers.

Periodically hypersensitive metrological scale that responds even to the breath of man, the state standard of "assessor" secondary standards. To avoid even the slightest tremors caused by movement on the street or work any machinery in the building, scales installed on the Foundation depth of 7 meters . To keep indoor constant temperature and humidity scales is controlled remotely from the next room.

For his nearly century-old existence of the national prototype kilogram, despite careful storage, yet changed his weight on 0,017 milligram. But this deviation is so slight that in April 1968, a platinum-iridium cylinder was again approved by the State standard of the kilogram of the USSR.

In the same safe in a special case is stored and a platinum-iridium rod, who recently served as the state standard meter. This linear unit is equal to one coronarienne part of the length of the Paris Meridian was established in France in 1791. Eight years later was made a primary reference standard meter, which is now in Paris, in the International Bureau of weights and measures. On it is inscribed: "For all times, for all peoples." The meter has indeed become the most common on our planet is a measure of length. Since 1889 and until recently, an exact copy of the Paris standard, even made of metal of the same melt, served as the "main meter" of our country.

Scientists are constantly looking for new ways to improve the accuracy of measurement standards, and in 1960, a platinum-iridium rod was forced to resign. To replace him came a beam of krypton lamp. More than twenty years the standard meter was a length equal 1650763,73 the wavelength of the orange radiation of krypton-86. But how can one use such a standard? These concerns fell on the shoulders of special interference device, which determines does the wavelength of the desired number of times in slychainoi metre least. But life goes on, and in 1983 the international Congress of Metrology adopted a new definition of the meter: now the meter is the distance that passes the laser beam for 1299791458-th fraction of a second.

There is another standard light, are also directly associated with platinum. As it is used glow emanating from the cavity of the tube (material for it is processed thorium oxide), immersed in molten platinum. The measurements were carried out during the solidification of platinum. Because at this time its temperature does not change, the unit of luminous intensity (Candela, or Candela) is reproduced with a very high degree of accuracy.

 Platinum is gaining a strong position in medicine.Platinum is gaining a strong position in medicine. Special electrodes from the metal introduced into the blood vessels that serve the surgeons in many countries for the diagnosis of various, mainly heart disease. This method is called platinum-hydrogen, because it is based on an electrochemical reaction between these elements.

An interesting and important application found platinum recently American doctors from Ohio. They have developed a brand new method of anesthesia, which consists in the following. A platinum plate with a length of several centimeters spinal cord connected to an electrical stimulator. At the slightest movement of the patient, the device sends an electrical signal to the brain, thus blocking pain.

In a large platinum honor among dental technicians, who are attracted by its neoteleostei is the most important material property for dentures. However, pure platinum is too soft to successfully perform this role, but its alloys having high strength, successfully serve as dental crowns and artificial teeth. First, to increase the hardness to platinum was added silver and Nickel, then for this purpose began to use gold and platinum metals. In Alliance with them corrosion resistant platinum gets to the same extraordinary wear any nut it becomes tough. A considerable part of the platinum mined in the world is doing today in the hands of the goldsmiths, who began to show her special interest after prices for the metal several times higher than the gold price. Already before the first world war came into Vogue platinum rings, brooches, earrings, pendants and other jewelry. Sometimes this precious metal have at the whim of the wealthy unpleasant to play the role it produce chain for your favorite lap or cells for scientists parrots. A few years ago in London demonstrated the novelty of the bathing season - beach costume mini-bikini". This modest outfit was worth "only" 50 thousand dollars, because the fabric was woven platinum threads and, in addition, of platinum was performed various decorations, modestly but tastefully complements the model. For obvious reasons, during the show's costume the model was accompanied by an armed guard. But if hall had one guard on the beach you will need a whole platoon of bodyguards. However, this is nothing.

Along with pure platinum jewelers use and its alloys with other metals, which are either to increase the hardness, or to make decoration cheaper per buyers with modest incomes, but do not wish however to keep up with fashion.

In the USSR platinum honour: it made the relief image of VI Lenin at the highest order of our country. On the eve of the Games of the XXII Olympiad, held in 1980 in Moscow, were issued Soviet Olympic coins. The most expensive of them is valued at 150 rubles - made of platinum.

 

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