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Sergey Venezky
STORIES ON METALS

COBALT

CHARGE PEACEFUL GUNS

The Focus Of Paracelsus. - Blue porcelain. - Secrets of the island of Murano. - Strange Saxon ore mountains. - Brandt defends the dissertation. - Hobby veterinarian. - There is a silver lining. - Like the stars. - Japanese steel. - Insidious "toys". - Damage to the British Navy. - The surprise of the old dumps. - In the star gave. - In Union with platinum. - How to remove a nail? - Stronger and cheaper. - In the fight against anemia. - Old memory. - Opening of the great spouses. - Like a fairy tale Genie. - "Cans" are being tested. - Are there any cracks? - Mask Of Tutankhamun. - The blue diamonds. - How to catch lightning? - Assistant doctors.

The famous doctor and scientist of the Renaissance, Paracelsus loved to show focus, which enjoyed success in the classroom. The scientist showed the picture, which depicted a winter landscape - the trees and the hills covered with snow. Giving viewers plenty to admire the painting, Paracelsus in the eyes of the audience turned winter into summer: the trees dressed leaves, and on the hills appeared pale green grass.

The miracle? But miracles do not happen. Indeed, in the role of a magician in this experience acted chemistry. At ordinary temperature a solution of cobalt chloride, to which plus some amount of Nickel chloride or iron, colorless, but if they write something, let dry, and then at least weak to heat, it becomes a beautiful green color. Such solutions and enjoyed Paracelsus, creating a wonderful landscape. At the right moment a scientist unnoticed by those present were lit behind the picture of the candle and on the canvas, just like in the fairy tale, I happened amazes audiences the changing of the seasons.

The focus of Paracelsus

True, he Paracelsus could not at that time know the exact chemical composition of their paints: for then neither cobalt nor Nickel were not yet known to science. But the use of compounds of cobalt as dyes had by this time already more than one century. Five thousand years ago cobalt blue paint used in ceramic and glass production. In China, for example, in those distant times the cobalt used in the production of the world famous blue porcelain. The ancient Egyptians blue glaze containing cobalt, covered clay pots. In the tomb of Pharaoh Tutankhamun archaeologists have found glass, painted blue salts of this element. The same glass was found and during excavations on the site of ancient Assyria and Babylon.

However, in the beginning of our era the secret of cobalt paints, apparently, was lost, as in blue glass, made in this period, the Alexandrian, Byzantine, Roman and other masters, cobalt was not kept, and the blue color, which was achieved by the introduction of copper, is clearly inferior to the former.

The parting glass with cobalt was delayed: only in the middle ages the Venetian master glass cases began to produce wonderful blue glass, which quickly gained popularity in many countries. Its success glass were obliged all the same cobalt.

The recipe of unique beauty products Venetians kept in the strictest confidence. To minimize the possibility of information leakage, the government of Venice translated in the thirteenth century all the glass factory on the small island of Murano, where outsiders "login" was prohibited strictly. Yes and leave the island without permission is not allowed to any of the specialists for melting colored glass. And yet journeyman Giorgio, Ballerina managed some way to escape. He got to Germany and opened in one of the cities in my glass Studio. But it lasted not long: once it "appeared" fire and it burned to the ground, and the fugitive owner found stabbed with a dagger.

The preserved documents of the seventeenth century show that in Russia there was a large demand expensive, but very persistent and juicy cobalt paint into a small package. Her walls were painted faceted and Armoury chamber. Arkhangelsk and assumption cathedrals and other great monuments of the Moscow Kremlin.

The high cost of cobalt colors was due to a very minor ore of this element. More precisely, cobalt ore industry simply did not know, as major concentrations of this metal in nature does not exist, and he only accompanied by relatively small concentrations of Nickel, arsenic, copper, bismuth, and some other items. That is why miners medieval Saxony for a long time and never knew that beneath their mountains contain no one slave then metal.

But from time to time they came upon a rather strange ore, which is on the external features was silver, but all attempts to get out of her silver was unsuccessful. Moreover, in the firing process from ore stood out poisonous gases, carrying miners a lot of trouble. In the end the Saxons learned how to tell real silver ore from its insidious copy that it came to be called "Kobold" name settled in her mountain spirit.

Discovering the underground foe metallurgists decided Swedish chemist Georg Brandt. For several years he studied the Saxon ore, including the infamous "Kobold". The fruit of his work was a dissertation On "semimetals" (In the essay "Eternal companion hardware readers have already met with the term "half-metal", which later became meaningless, and former semimetals acquired the status of metals), published in 1735. Brandt wrote: "I had the good fortune to be the discoverer of a new semimetal,... who has previously been confused with bismuth". This "half-metal was metal, called "cobalt". If such an important discovery was made in our days, teletypes immediately spread the news about him in the light, but the eighteenth century had no such mighty and online media. So many years of thesis Swedish chemist knew only a few. Few people recognized the cobalt rights of citizenship: it was believed that it is a mixture of different elements with some "special land". Only in 1781 French chemist Pierre Joseph Macaire finally convinced the scientific world that the cobalt is cobalt and nothing more.

By this time was already open and the closest chemical relative of cobalt - Nickel. These metals in nature often appeared next, and not by accident before scientists have a question: how to split them to get both in pure form?

The answer to this question was found quite unexpectedly. The most difficult chemical problem was resolved... the veterinarian Charles Askin. Things were so. All the free time the vet was dedicated to his hobby - metallurgy. In 1834 he became interested in Nickel and its alloys. Askin attempted to extract the Nickel from the ore. But unfortunately (however, it is fairer to say, fortunately), this ore contained besides the cobalt. What to do? Askin appealed for help to the owner of the local chemical plant Benson. As it turned out, he just needed the cobalt, which he used in the production of ceramics. However, and Benson were not well-known methods of separation of these metals. After some deliberation, they decided to use to achieve its goal of bleach, just calculated how much . you will need: for work, and each of them began to work.

Benson, who had enough bleach, measured need her number and tried to process its ore, but achieved nothing: from the solution to precipitate out the oxides and Nickel, and cobalt.

Askin, ready to start the experiments, found that it has only half of the calculated quantity of bleach. "This is unlucky, so unlucky", " must be, he thought, but still didn't postpone the experiment. But no wonder they say that there is a silver lining. To the surprise and joy Askin, experience, not promising him, it would seem, no success, gave the desired result: cobalt oxide knocked out, and Nickel, which was not enough bleach, almost all remained in solution. Later this method was slightly improved and today is widely used in industry for the separation of related metals.

Prior to the beginning of the twentieth century, the field of activity of cobalt was very limited. Metallurgists, for example, are now with respect to the cobalt, then had a vague idea of its properties. In the book "metallurgy of non-ferrous metals", published in 1912, the author stated: "...to date metallic cobalt from the point of view of consumption is not of interest... there Were attempts to introduce cobalt in the iron and cook special steel, but the latter have not yet found any use".

However, even in the five years before the appearance of this book by the American Metallurgist Haines has created a wonderful group of alloys of cobalt (up to 50%) with chromium and tungsten, possessed of enormous strength, resistance against corrosion and abrasion. For the bright Shine of the polished surface alloys were called stellites (from the Latin word "Stella" - star). Weld on the edge of the cutting tool or work piece surface layer of Stellite several times increases their lifespan.

The production of hard alloys in the future has grown steadily, and cobalt played not the last role. So, more than half a century ago, the Soviet scientists and engineers have developed a solid alloy "win", which, along with tungsten carbide, includes cobalt.

The Curie point: higher and higher and higherIn 1917, Japanese scientists Honda and Takagi received a patent for their steel containing from 20 to 60% cobalt and characterized by high magnetic properties. The need for such a steel, which has been called a Japanese, was enormous: the end of XIX and beginning of XX century was marked literally invasion of magnets in the industry, and this was due to a famine in magnetic materials.

Of the three main ferromagnetic metals such as iron, Nickel and cobalt - last has the highest Curie temperature, i.e. the temperature at which the metal loses the property of being a magnet. If Nickel Curie point is only 358°C, iron 769°C, cobalt it reaches 1121°C. And because the magnets have to work in a variety of conditions, including at very high temperatures, the cobalt was destined to become an important component of magnetic steel.

Cobalt steel immediately attracted the attention of military officials and Industrialists, smakowski that its special properties can be used for purposes not harmless. Already in the years of the civil war our sailors and soldiers, who fought on the North by the invaders, happened to meet unusual mines, which, without even touching him, was undermined by the minesweepers Severodvinsk flotilla. When divers fished and drove one of these insidious "toys", she was magnetic, and its principle of operation was as follows: as soon as the steel case approaching a mine ship was in the area of force lines of magnetic field, worked the mechanism of the fuse and the ship was sinking.

On the eve of the second world war in Nazi Germany the production of cobalt steels, which served as material for the manufacture of magnetic mines, has increased markedly. As argued Goebbels propaganda, German mines accuracy, sensitivity and responsiveness "is superior to the nervous system of many higher beings, created by the Creator". And indeed, when the Germans managed to mine with air coast of England, the mouth of the Thames river and other major rivers, magnetic mines caused great damage to the British Navy. But every poison is the antidote: for about two weeks after the treacherous attack of Nazi Germany on the Soviet Union, our military experts have cleared the area of Ochakov first German magnetic mine.

To the period of war and is an event that occurred on one of the Ural mines. In old dumps concentrator, processing for many years copper ore was discovered cobalt, about before this no one had suspected. In a short time the technology was developed for the extraction of cobalt, and soon the military industry has gained valuable metal, extracted from "empty" breed.

During the war, cobalt began to be used to create heat-resistant steels and alloys that come on the manufacture of parts for aircraft engines, missiles, high pressure steam boilers, blades of turbo-compressors and gas turbines. Such alloys include, for example, Vitallium containing up to 65% cobalt. Drew attention to this metal and experts in space technology, which not without reason, believe that here he will have to court: why, cobalt alloys confident resist shock loads than widely used in missile Nickel alloys.

Although cobalt and roads, but there are areas where he successfully replaces the more expensive metal platinum, the annual output of which will easily fit in the truck. Electroplating common insoluble anodes, which must not react with the contents of galvanic baths. Very suitable for these purposes the material is platinum, but platinum anodes cost a pretty penny. Replacing platinum with cheaper metals has long bothered the minds of scientists. In the result of meticulous research succeeded in developing the composition of the alloy, not only not inferior to platinum, but its superior ability to resist strong acids. The composition of the alloy includes up to 75% of cobalt.

In some cases, the cobalt is in Union with platinum. So, one of the UK firms have created a magnetic alloy of these metals platinax, which also has a high anti-corrosion properties, easily machinable. From it produce miniature magnetic components for electric clocks, hearing AIDS, sensors for various purposes.

Known and other magnetic alloys of cobalt - hornless, vicalloy, Alnico, Magnito, permendur and perminvar. About magnetic abilities alloy Alnico can be judged by this fact, described in the literature: in the 50-ies using a permanent magnet in the form of a rod, the material for which was this alloy was removed a nail from the bronchi of the child and thereby saved his life. But, perhaps, the strongest permanent magnets could be made from compounds of cobalt, some rare earth elements, such as samarium. To separate these small, smaller than a matchbox, a plate of such material, the strength is that well-trained weightlifter.

Cobalt alloy is an excellent material for denturesGreat material for frames dentures were cobalt-chrome alloy which is much stronger than gold (usually used for this purpose) and, as you can guess, much cheaper.

In medicine, the cobalt is in a different role: it is an essential component of vitamin B12, contributing to the formation in humans, red blood cells. For making this an effective tool in the fight against anemia English chemist and biochemist Dorothy Crowfoot-Hodgkin in 1964 awarded the Nobel prize.

In ancient times it was famous the whole world of beautiful porcelain of different colors, izgotovlenie in China. Blue color, they gave compounds of cobalt. This element in our day will not part with porcelain - it is part of the blue dye. And Georgian specialists in ceramics managed to get a beautiful black porcelain, which owes its color volcanic stone, andesite, interacting in the firing process with cobalt oxide.

So far, we talked about the usual cobalt, but since then, in 1934, the famous French scientists Frederic and Irene Joliot-Curie discovered the phenomenon of artificial radioactivity, science and technology began to show great interest in radioactive isotopes of various elements, including cobalt. Of the twelve radioactive isotopes of the metal most widely used cobalt-60.

Its rays have high penetrating power. Power radiation 17 grams of radioactive cobalt is equivalent to 1 kilogram of radium - the most powerful natural source of radiation. That is why you are receiving, storage and transportation of this isotope, as well, and the other, carefully comply with the strictest safety regulations, take all necessary measures to reliably protect people from the deadly rays.

Once in a nuclear reactor of the usual metallic cobalt becomes radioactive, its like the magic Genie, crammed in a special massive containers that look just like milk cans. These containers are surrounded by a layer of lead cobalt-60 is moved to a special machine to place future work. Well, what if the car gets into an accident - container-"churn" may shatter, and then hidden in it ampoule with cobalt will threaten people's lives? No, this will not happen. Of course, from a road traffic accident is not insured, no car, but even if it happens, "the churn" will remain unharmed. In fact, before becoming a repository for radioactive isotope, the containers pass through severe trials. They are left with a five-meter height on concrete slabs, placed in a heat chamber, is subjected to different tests, and then they gain the right to adopt in its womb the little vial with a radioactive substance. All these precautions are doing the work of people associated with sources of nuclear radiation, almost safe.

Radioactive cobalt - Genie forced into the bottle - special cans

The radioactive cobalt many professions. More and more wide application in industry finds, for example, gamma radiography, i.e. quality control by x-raying her gamma rays that originate from the isotope cobalt-60. This method of control allows using relatively inexpensive and compact apparatus can easily detect cracks, voids, cracks and other internal defects massive castings, welds, assemblies and parts that are in hard to reach places. Due to the fact that gamma rays source uniformly in all directions, the method gives a possibility to control simultaneously a large number of objects, and the cylindrical article to check immediately around the perimeter.

Using gamma rays managed to resolve long interested scientists, Egyptologists question about the mask of Pharaoh Tutankhamun. Some claimed that it is made from a single piece of gold, others believed that it was assembled from separate parts. It was decided to enlist the help of a cobalt gun - special device, one isotope of cobalt. It turned out, the mask really consists of several parts, but so carefully adjusted to each other that to notice the line of junction, was absolutely impossible.

Radioactive cobalt is used for control and regulation of the level of molten metal in the melting furnace, the level of charge materials in blast furnaces and bunkers, to maintain the level of liquid steel in the mould of a continuous casting plant.

The device, called gamma-ray thickness gauge, quickly and with great precision defines the thickness of the plating vessel hull, the walls of pipes, boilers and other products, when their inner surfaces cannot be selected and therefore, conventional devices are powerless.

Radioactive cobalt catches lightningFor the study of technological processes and investigation of the conditions of service of various equipment find wide application of the so-called "tracers", i.e. radioactive isotopes of several elements, including cobalt.

In the Soviet Union for the first time in the world created by industrial radiation-chemical reactor, in which the source of the gamma rays is still the same isotope of cobalt.

Along with other modern methods of exposure to various substances such as ultra-high pressure and ultrasound, laser and plasma processing, " radiation exposure is being widely implemented in the industry, allowing you to significantly improve the properties of many materials. So, tires subjected to radiation vulcanization, are 10-15% longer than usual, and fabric for school costumes, to the threads which use radiation "grafted in" molecules of polystyrene, is twice stronger. Even precious stones after radiation "treatments" become even more beautiful: diamond, for example, under the action of fast neutrons acquires a blue color, slow neutrons make it green, and the rays of cobalt-60, give him a gentle bluish-green color.

Radioactive cobalt is working and the agricultural field, where it is used to study soil moisture, determination of water in snowpack, pre-irradiation of seeds and other purposes.

An interesting discovery was made by the French scientists. They found that the radioactive cobalt can successfully serve as... bait for lightning. With a small addition of isotope in the rod lightning rod the air around him as a result of gamma radiation ionizes in significant quantities. Lightning discharges occur in the atmosphere, attracted, like a magnet, to radioactive lightning rod. This new product helps to "collect" lightning in a radius of several hundred meters.

In conclusion, we say about another, perhaps the most important profession of radioactive cobalt. He was a reliable ally of doctors in their struggle for people's lives. Grains isotope cobalt-60, is placed in the medical gun, no harm to human body is bombarded with gamma rays internal malignant tumors detrimental effect on proliferating sick cells, suspending their activities and thereby eliminating pockets of terrible disease.

In the underground vaults of the all-Union Association "Isotope" there are dozens of containers, small and large. In them - radioactive cobalt, strontium, cesium and other sources of nuclear radiation. Time comes, and they go to hospitals and clinics, enterprises and research institutes - hood where today the peaceful atom.

 

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