What is palladium? This is a platinum group metal, which has characteristic properties. Today it is considered one of the most expensive and sought after. Used in various industries, but most often - in engineering.
Palladium - No. 46 on the periodic table
How is mined in nature?
Pd is rarely found in nature in its pure form, mainly in combination with other metals, such as platinum, gold, silver and copper. In the form of nuggets to meet palladium is difficult, but possible.
Metal mining takes place in two ways:
- At the primary deposits.
- On alluvial deposits.
At primary deposits, palladium is mined as a companion material in the processing of copper and nickel ores.
At placer deposits mined metal in the form of nuggets, where it accumulated for many years. Nuggets are found mainly in ore mining sites.
Natural palladium nugget
- nuggets make up 2% of total production,
- the remaining 98% of the metal is mined during the development of primary deposits.
It should be noted that the extraction of Pd is carried out on the territory of our country. There is one of the largest deposits in the Urals, although its resources are almost exhausted. In Russia, the metal is mined in the Far Eastern regions.
Pd mining occurs in the following countries:
In Russia, Norilsk Nickel is engaged in the extraction of metal, extracting precious metal in the extraction of the main material of its production - nickel and copper.
Pd properties allow it to be used in many industries. Palladium is different from other metals:
- chemical inertness
- low density.
It has an appearance similar to silver.
The melting point of palladium is 1555 ° C. Due to the salts of ductility and plasticity, the metal is used to make jewelry.
But in its pure form, palladium is classified as a fragile, fragile metal, it is well treated, but jewelry made from this material will not be durable. You can spoil the product with a weak mechanical effect.
For this reason, the use of palladium in jewelry is carried out by creating a ligature. That is, other metals are added to the alloy for making jewelry.
- Does not oxidize in nature.
- Does not react.
- Forms compounds with other chemical elements.
The properties of Pd suggest that it is an inert metal that does not oxidize, being under the influence of natural factors, as, indeed, all metals of the platinum group.
Palladium does not react with other metals, but dissolves in a mixture of sulfuric and nitric acids, which chemists call "aqua regia."
Pd forms compounds with boron, chlorine, silicon and sulfur.
Metal properties are valued in the manufacture of jewelry. Decorations made of palladium and other metals alloy are wear resistant, they are not influenced by environmental factors and retain their luster and color for a long time. The raid on their surface is formed slowly.
A palladium bracelet or watch will be worn longer than others, white gold earrings or a ring will delight not only with beauty, but also with resistance to chemicals and moisture.
Pd properties are valued not only by jewelers and motorists, but also by chemists and physicians who actively use metal for various purposes.
Externally, the metal has a certain similarity with silver in color. Due to inertness and other qualities, palladium is used in the following industries:
- production of catalysts for cars,
The use of palladium in the production of catalysts is a necessary condition for the production of a car of any brand. Necessary for afterburning exhaust. Interest in this metal is due not only to the desire of citizens to have a car, but also to EU standards. Pd helps to reduce the amount of exhaust gases, so the popularity of the metal is growing steadily.
Palladium ingot from the plant Krastsvetmet Krasnoyarsk
Jewelry made from Pd and other precious metals is invariably in demand. But the jewelry industry does not affect global production volumes due to the fact that it is almost impossible to meet products made of pure metal. Palladium is added to the composition of the ligature, with which make watches, cufflinks and other accessories. In addition, commemorative coins are minted from the ligature to the numismatists' joy.
In medicine, metal is used to make parts for pacemakers, as well as special dishes and tools.
Investing is buying Pd in the form of bullion. You can also open a bank account, but the depositor will not see the ingots. But with their direct purchase will be able to hold in the hands of palladium. This investment brings investment only in the long term.
In electronics, Pd has found its use in the production of military aerospace technology. And also to create a special coating that protects parts from the effects of negative environmental factors, prevents oxidation. The metal is part of the ceramic capacitors, which are used for the manufacture of motherboards. Thus, a small amount of Pd is in mobile phones, computers and other household appliances.
The chemical industry uses the 46th element of the periodic table for the manufacture of dishes, various flasks and other containers. And also for the separation of acetylene, ammonia, chlorine and other substances for the purification of hydrogen.
The use of palladium for the purification of hydrogen is not used in its pure form. To reduce the cost of production in the industry, palladium is combined with nickel and other metals.
What is affining?
Palladium refining is the process of its separation from other metals. Used in the laboratory, but often chemists and enterprising craftsmen are ready to carry out refining at home.
This is due to the fact that:
- The element is used in a large number of chemical reactions.
- You can take it and get a reward.
The cost of one gram of Pd ranges from 1000 rubles and above. Therefore, it is much easier to donate a few grams of palladium than to collect parts from a computer and a radio.
You can try to get Pd in two ways:
- dissolution in aqua regia.
If you try to remove the Pd from the parts by electrolysis, then there can not do without a mixture of sulfuric and nitric acids. Electrolysis is carried out in a concentrate of sulfuric acid, the main part of parts made of copper and brass will not suffer, it will remain. During the process, palladium itself is not formed; it will be possible to separate the alloy, which contains Pd. The resulting alloy must be dissolved in aqua regia.
How to determine palladium? It will be removed from the parts in the form of black powder or flakes. As long as the electrolyte is clean, washing is done simply; if the solution has warmed up, it must be cooled. Sludge treatment is carried out with the use of aqua regia.
During operation, a voltage of 11–13 volts is necessary; it is supplied before the part is immersed in the solution. It is also necessary to consider the process of separating Pd from other elements, such as silver, gold, etc. This will require nitric and hydrochloric acids, as well as a solution of ammonia and water.
Nitric acid along with sulfuric helps to separate Pd from other elements. To understand that palladium is in solution, you can simply assess its color. During the reaction, the solution acquires a characteristic brown tint. This indicates that Pd is present in the composition of the alloy and it makes sense to continue the experiments.
If there is gold in the composition of the alloy, then the solution is left for a day, pre-filled with cold water. Next, silver chloride is filtered, with the result that only gold and Pd remain in the solution.
The palladium refining procedure is carried out with the help of ammonia. It connects with the solution, the mixture is left for two days, after which you can filter the gold, and the palladium will remain in the solution. In the future, gold can be restored with the help of hydrochloric acid and zinc.
Hydrochloric acid should be added to the solution with Pd - an orange or yellow precipitate appears. After a few hours, the precipitate should be filtered, dried and calcined at a temperature not lower than 500 degrees. As a result of the procedure, Pd refining can be obtained. A certain amount of the precious metal will remain in the solution. It can be obtained by repeated refining.
The efficiency of the process depends on how much palladium is contained in the details, as well as on what elements besides Pd were part of the alloy.
In general, the procedure is quite complicated, it requires certain skills in chemistry, sometimes a positive result can be obtained only through trial and error.
We are children of the stars.
. and in the literal sense, and most of the body. More - because some of the chemical elements that make up both human and celestial bodies, formed outside the stars. Palladium is the “son” of two processes at once in the Universe. Part of it is synthesized in reactions that occur in massive stars. Part of the palladium, as well as the other platinoids, is formed during supernova explosions.
The metal thrown into interstellar space sooner or later becomes part of a gas-dust cloud, from the array of which stars and planets are condensed. Colliding and collapsing, celestial bodies break up - these are the pieces that the Earth collects on its journey through the orbits of the galaxy. The marked seven kilograms of palladium are contained in two thousand tons of meteorites falling on our planet in a year.
A considerable amount of palladium is concentrated in the burnable nuclear fuel of nuclear power plants. For understandable reasons, it is impossible to use metal from uranium-plutonium slag in any way. So immediately - it is impossible, but after 10-15 million years (quite a bit by the standards of the Universe) - it is possible!
Two centuries since the discovery of palladium
The honor of discovering palladium belongs to a not too diligent English doctor, who has shown remarkable research insight and excellent commercial deplorescence.
William Wollaston, at that time already a full member of the London Royal Society for the Knowledge of Nature, in the last years of the 18th century, started a profitable business for the production of platinum dishes. Experimenting with the ore residue of platinum, Wollaston identifies new metals, one of which the scientist gives the name "palladium", and the second - "rhodium".
The name of palladium is sufficiently random. In the early 1800s, the Greek goddess Pallas Athena was at the hearing: her name was given to a newly discovered asteroid. In 1803, two years after the momentous event, Wollaston gives the “new silver” the fashionable name of a wise warrior.
At the beginning of the XIX century, many enlightened people science served as entertainment. Not without its easy hoax and Wollaston. The announcement given to them read: an open noble metal is open, in appearance and properties similar to silver. Offered for purchase.
The ambitious Irish chemist Richard Chenewix, who had just received the highest award of the Royal Society, decided to turn his success into a triumph, and publicly promised to bring the fraudster to clean water. According to Cheneviks, the unknown charlatan only used the little-known Musin-Pushkin method, which allowed him to alloy mercury with platinum.
Having redeemed the sold bar, Chenevix hastily conducted research, and soon reported to the meeting of the academic council that he was right. It remains only to expose the falsifier!
And then an advertisement appears in the newspaper: someone promises to pay £ 20 to anyone who can float platinum with mercury in such a way that a “new silver” is made.
With rage, turning into frenzy, Chenewix embarks on experiments. At the same time other London chemists are working. Needless to say, none of them can neither synthesize palladium, nor select platinum and mercury from the ingot bought by Chenewix.
A year after the start of the epic, Wollaston delivers a detailed account of the discovery. Soon he is elected president of the Royal Society. Richard Chanewicks has to quit chemistry.
Extraction and use of palladium
Today, geologists account for three dozen minerals, including palladium. A considerable amount of metal is included in the native formations of gold, silver and platinum. In Norilsk platinum palladium - almost half! Brazilian prospectors have found gold nuggets with a ten percent content of noble metal.
The deposits of palladium ores, as a rule, coincide with deposits of other non-ferrous metals, including nickel, mercury, and copper. According to current estimates, the most promising palladium reserves are concentrated in Norilsk.
Amazing palladium properties made it indispensable in the chemical industry. The ability of palladium to absorb hydrogen in a volume that is almost a thousand times greater than the volume of the metal is amazing! The use of palladium catalysts in the technological cycle of margarine production made it possible to abandon the previously inevitable contamination of the food product with nickel.
Hot palladium is easily permeable to hydrogen. A millimeter-thick metal plate, installed as a membrane, removes hydrogen from complex gas compositions and solutions that do not otherwise render hydrogen.
Palladium alloys do not oxidize even under electric arc.that opened the way for them in the electrical industry. Titanium with a small addition of palladium exhibits properties of increased resistance to various chemical loads. Not without palladium and medicine: the metal is used in dentists, cardiology, pharmaceuticals.
Palladium in jewelry
By itself, palladium is very decorative and can compete in expressiveness with silver, and - especially with platinum. Palladium-type alloys are highly valued by jewelers.
The so-called “white gold” is most often nothing more than the combination of gold with palladium. A soft, discreet shine of the noble metal is the best frame for diamonds! The palladium-indium alloy, depending on the concentration of the ingredients, can vary in color from a characteristic gold color to a pronounced lilac color.
Wedding rings made of high palladium alloy (palladium samples - 500, 850, ligature - silver) are visually indistinguishable from wired gold rings. At the same time, the owner of the jewelry does not need to periodically renew the rhodium coating. And the price of palladium is somewhat inferior to gold.
The addition of palladium to platinum makes the product more expressive and improves the technological properties of the material.
Speaking of where palladium is used and where it came from, it is worth mentioning an English chemist named William Wollaston. It was he who received this metal, back in 1803. And the name of this element was given in honor of the asteroid Pallas, which became known to the world shortly before the removal of this metal by laboratory. In those days, it was difficult for people to find a destination for the new element, so for a certain period of time it had to lie idle.
By itself, palladium has a silvery-white shade. As for its appearance, it resembles the usual silver. The physical properties of this element were found such:
- boiling point - 2 940 ° C,
- density - 12.0 g / cm 3,
- elastic modulus - 12,600 kgf / mm 2,
- melting point - 1554 ° C,
- Brinell hardness - 52 kgf / mm 2.
It is also worth noting that even today, the metal in question is recognized as one of the rarest on the planet. Only 0.000001% is present on the whole earth.
Another interesting feature of the element is a change in its structure starting from heating from 18 ° C. And with a further increase in this indicator changes become irreversible.
To palladium, scientists add elements of the platinum group. Due to this, they manage to significantly improve the properties of the precious metal. For example, with the addition of ruthenium and rhodium, the chemical element becomes twice as strong and elastic.
The active use of palladium in various fields of activity is also explained by its chemical properties. First of all, it should be noted that it has a sufficiently high inertia, as well as galvanic resistance, which is extremely rare in modern metals. Such properties are explained by the atomic structure of the element. It is also worth saying that it does not interact with acids, water molecules and alkalis in any way; therefore, the simplest school experiments on it cannot be put on, although it is unlikely that anyone will get it for such purposes.
If the metal is heated to 350 degrees, its resistance will remain stable. But with an increase in this indicator, it will begin to oxidize. As a result of this reaction, a dull oxide film is formed on the metal surface. If you heat it to 850 degrees, you can observe its decay. Объясняется это явление тем, что в диапазоне температур от 800 до 850 градусов элемент уже имеет устойчивость к окислению и не поддается ему.
Не так давно ученые выяснили один интересный факт. Суть его в том, что раствор азотной кислоты способен делать тоньше чистую титановую пластину на 19 мм в год, а в случае сплава палладия с тем же титаном истончение будет происходить гораздо медленнее – всего 0,10 мм в год.
Heating up to 500 degrees, the element successfully interacts with various oxidants, including fluorine. Due to this, scientists have been able to conduct a lot of research.
An additional chemical property of palladium is its ability to enhance the anti-corrosion capabilities of titanium. When a precious metal is added to this element, its resistance to aggressive media increases significantly.
The medical field of palladium has not yet been fully investigated. At the moment, scientists are still finding out the biological properties of this element. But on the other hand, they have already discovered its healing capabilities, thanks to which it is actively used in medicine as complex compounds for the preparation of cytostatic preparations.
Where is palladium mined
Today, the use of palladium in Russia is to thank the company Norilsk Nickel. It is she who holds the first place in the extraction of this precious metal. The holding produces about 41% of palladium raw materials all over the globe. The main deposits are located on the Taimyr Peninsula, which is located in the Arctic. Copper-nickel deposits are present there, where measures are taken to extract the precious element.
South Africa is considered the second state in terms of palladium production. There are deposits that provide about 38% of metal production in the world.
The remaining share, which is 21%, is divided into several fields located in such countries:
- Canada - 9%,
- Zimbabwe - 3%,
- North America - 6%,
- Colombia, Australia and others (together) - 3%.
The use of metal in medicine
And where is palladium used? Speaking specifically about the medical field, here from this element are created all sorts of auxiliary means for dental prosthetics. It is also used in the manufacture of pacemakers. In addition, palladium is used to treat cancer - it is used in the manufacture of anticancer drugs.
Importance in jewelry
Especially important is the use of palladium in the jewelry industry, since products with its participation are quite attractive and delight the eye of not only beautiful women, but also of the opposite sex. As a rule, the metal in question is used as an independent ornament, but sometimes acts as a supplement to silver and gold products. It is not customary to combine it with other precious metals. In addition, products with his direct participation are almost never supplemented with precious stones.
Palladium in the automotive industry
The use of palladium in the industry, or rather the automotive industry, is not so wide. Only catalysts are manufactured with his participation. Although for several years scientists have been thinking about where else this element can be applied in this area.
Recent statistics indicate that in recent years, the amount of palladium used in the automotive industry has decreased by about three times. Although at the same time its production was increased by more than 25%. The reason for such phenomena lies in the cost of the metal - it grows with the needs of the automotive industry.
Where is palladium used in industry? The above list of industries is not exhaustive. Such a precious element is also actively exploited in the following areas:
- Electrotechnical and electronic. Here the metal in question takes an active part in the development of thermostats, capacitors, thermocouples, and electrical connectors. All this with the participation of the considered element began to be made not too long ago. The technology quickly gained popularity, so in this direction there are not yet any changes regarding the elimination of palladium or the addition of new products based on it.
- Chemical. Workers in this industry actively use the element as a catalyst, that is, a special accelerator for certain reactions. Unfortunately, it interacts with far from all the elements of the periodic table, but this does not prevent us from developing new reactions with his direct participation.
- Investment. Oddly enough, palladium and here have found beneficial use. From it minted valuable coins and used for financial investments.
- Food. Here you can also find the item in question. It is sometimes used to create elements of dishes. This is ensured by the well-known fact that the precious metal has chemical neutrality. At the same time, the products made with his participation are practically the same as usual, but their price is much higher.
For one gram of palladium in its pure form, you will have to pay at least 1,300 rubles. As for the products in which it is included, everything depends on the percentage of the content of the metal.
Specialists who buy the precious element, independently share prices in this way:
- contacts, needles, knitting needles, etc. (palladium content is 18–28%) - about 350 rubles per gram,
- wrapping with strings and other things (80% of the element in the composition) - more than a thousand rubles per 1 g,
- coins (Soviet 5, 10 and 25 rubles - contain about 99.9% of this metal) - from 1,400 rubles,
- scrap of radio components (limiters, resistors, ligature SHIV, gas mask filters) - the cost is calculated individually, based on weight, product category and other characteristics,
- palladium chloride (brown powder with crystals) - one thousand rubles per kilogram.
Although palladium is considered a rare metal, information about it has been obtained enough to understand what it is. It has many interesting properties and its study is still ongoing. The list of industries in which this element can be used is constantly expanding. The cost of palladium is not as high as one might expect at first glance, although only a few are in a hurry to buy such a product.
In 1801 a planet was discovered by the German scientist Olbers, which was called Pallas. This discovery was a sensation and made a huge impression on the famous chemist Wollaston. Therefore, when two years later he was able to get a new element out of raw platinum, he gave him the name palladium.
Palladium is the lightest element of the platinum group. Its density is about 12 g per 1 cubic centimeter. In its pure form, the metal has a silvery-white color, there are no other shades.
Many properties of the metal are similar to the properties of other noble elements. For example, the mineral is quite plastic, malleable and has good ductility. Just like gold, it can be easily stretched into the thinnest sheet or shaped into any shape, soldered, polished or engraved.
But if you compare an element with platinum, then in some qualities it is inferior to it. For example, it reacts with sulfuric and hydrochloric acids. And nitric acid is able to dissolve it completely. With respect to other elements, palladium is an inert metal.
The element is present in white gold. And the important task is to separate it from bismuth and arsenic, which, like palladium, dissolve in nitric acid.
To do this, perform the following manipulations:
- The nitrate of elements such as silver, palladium and bismuth must be evaporated to a syrup state. In the case of palladium, this will help remove residues of various acids from them.
- Next, the mixture is diluted with purified water.
- Concentrated hydrochloric acid is added. A white sedimentary deposit is formed, similar to cottage cheese - silver chloride. It must be separated to make the solution clear.
- After that, the composition is evaporated. When this occurs, the removal of hydrochloric acid.
- Ammonia is added to the mixture. The composition should be blue or green. Flakes will start to fall out - bismuth chloride. It does not dissolve in ammonia.
- The mixture is filtered. Hydrochloric acid is added to it. The result is palladium sulfide.
- After the end of the reaction, a yellow precipitate is formed in a transparent solution with a yellowish tinge.
- Palladium sulfide must be thoroughly rinsed and free from water.
- Next, palladium sulfide can be restored to the state of the metal. To do this, it must be melted down again.
- In order to give the metal a marketable appearance, palladium sulphide is best recovered with hydrogen sulphide to mobile. Then it must be re-fused. After that, palladium sulfide is granulated.
Since palladium is a soft metal, it is not used in its pure form. Such an alloy will not be able to withstand even a small external impact.
Jewelers use to work the mineral with various impurities. The alloy sample depends on their number and name.
The main samples of palladium are presented in the table.
All metals give the element hardness. And if you add gold or silver, you can increase the wear resistance of the alloy.
Extraction and use
Palladium is a precious metal alloy that is part of more than 30 minerals. Found in the form of nuggets. A large amount of the element is included in gold and silver alloys.
Palladium is considered a rare precious metal. It is much less common than gold. Among the main mining sites are:
- Norilsk platinum. It is an important element deposit. Here, more than half of all minerals is palladium. The rest is mercury, copper, nickel.
- A large amount of metal is mined in Brazil. Here are nuggets with an element content of more than 10%.
The use of metal palladium is different. There is practically no area where it is not used:
- Due to its amazing properties, the metal is widely used in the chemical industry. The element is able to absorb the amount of hydrogen 1000 times the amount of the metal itself. Therefore, it is used as a catalyst, for example, in the production of margarine. This eliminates the possibility of nickel entering the product.
- This element is also used to remove hydrogen from solutions and gas mixtures. This can be done by setting a palladium millimeter plate as a membrane.
- Metal alloys are not susceptible to oxidation, even under an electric arc. This allowed the use of the mineral in the electrical industry. For example, titanium with a slight addition of palladium significantly increases the stability of the composition to the occurrence of chemical reactions.
- Metal is also used in medicine, in particular, cardiology, pharmaceuticals for the production of acetylene, and in dentistry for dental prosthetics. The element significantly reduces the cost of prostheses, leaving the quality at a high level.
- Apply element and in industry - for the production of pipes. The metal can stretch until the load reaches 18.5 kg per 1 square millimeter. Adding rhodium with ruthenium, you can increase the performance of the alloy. This allows you to create pipes without seams and adhesions.
- More than 70% of all mineral extraction is used in mechanical engineering. The element is used as an engine catalyst, making the exhaust gases cleaner.
- About 15% of the metal is used in electronic manufacturing.
- Only 10% of the mineral is used in jewelry. But these alloys are highly appreciated by jewelers. The most popular is an alloy with gold impurities, resulting in gold, called white. Due to its soft luster, it is considered an excellent border for diamonds.
A mixture of palladium and platinum is often used. It not only enhances the technological characteristics of the metal, but also gives the ornament greater expressiveness.
The cost of 1 g of palladium on the stock exchange is almost 1,500 rubles.
If it speaks of scrap, then it is worth knowing that the product of high standard and with artistic design is more expensive. For the decoration of 500 samples, buyers will offer no more than 550 rubles. But if the amount of the donated item is 500 g and more, the cost will increase.
Being in nature and prey
Extraction of platinum and palladium is carried out at primary and placer deposits. How do they differ from each other? In the primary deposits of the metal is part of the minerals and mined as a by-product in the processing of nickel or copper ores. Loose deposits are permitted indigenous ore deposits, where Pd was released and accumulated in the form of nuggets.
The extraction of palladium in placer deposits takes about 2% of the world production of the element. The largest of them are located in the Urals and Far Eastern regions of Russia, in Canada, the USA, Australia and Colombia. The remaining 98% of Pd is extracted from the depths of the earth at the primary deposits of copper-nickel, platinum and chrome ores.
World leaders in the extraction of precious metals in such deposits are Russia and South Africa. The unconditional first place among the mining companies in the industry is occupied by the MMC Norilsk Nickel, which produces more than 40% of the global Pd volumes. Metallurgical plant extracts the metal as a side element in the extraction of its main products - copper and nickel. Among the extractive assets of Norilsk Nickel, which have the potential for palladium reserves, there are deposits on the Taimyr Peninsula - Talnakh, Oktyabrsk and Norilsk-1, as well as on the territory of the Kola Peninsula.
The next most important source of metal in the world is called the Bushveld complex located in the territory of the Republic of South Africa. The territory of the field has the largest reserves of platinum in the world.
Pd in nuggets has impurities of other precious metals, but it is often one of the elements of native gold or platinum itself. When palladium was mined in Norilsk, geologists discovered palladium platinum, a compound of platinum and its “younger brother” in the ratio of 60% / 40%. Another similar union, this time with gold, was found in Brazil. Such gold with a 10% Pd content is called porepezite: it is also problematic to distinguish it visually from pure yellow metal.
What minerals are palladium found in? You can see them in the photo samples. The best-known Pd minerals are palladite, stun-palladite, braggit, and sweat. Some compounds even today have no names, since they are little studied due to their rarity.
The Pd element is a component of not only the bowels of our planet, but also of space objects: palladium is contained in iron and stone meteorites arriving on Earth.
Palladium is the definition
Palladium is extremely heavy and very refractory ductile and ductile metal, which is very easily rolled into a foil and pulled into a thin wire. In terms of density, which is 12 g / cm3, palladium is nevertheless closer to silver, whose density is 10.5 g / cm3, than to related platinum (21 g / cm3). Palladium in nature consists of six stable isotopes: 102Pd (1.00%), 104Pd (11%), 105Pd (22%), 106Pd (27%), 108Pd (26%) and 110Pd (11%). The most long-lived and artificial radioactive isotope 107Pd with a half-life of more than seven million years. Many palladium isotopes are formed in small quantities during the fission of uranium and plutonium. In modern nuclear reactors in 1 ton of nuclear fuel with a degree of burnout of 3%, contains about 1.5 pounds of palladium.
Palladium is one of the elements of the periodic table of chemical. elements named Mendeleev. In the table, this element has the sequence number 46 and is located in the fifth period of the elements.
Palladium is noble metals belonging to the platinum group. In itself has a white - silver color.
Palladium is the only chemical element with an extremely filled outer electron shell. There are 18 electrons in the outer orbit of the palladium atom.
Paladium is an element that is often used in the preparation of white gold or as a base of palladium alloy. Even 1-2% of palladium is enough for gold to become a silvery-white shade. But most often, white gold of 583 samples contains 13% palladium. It is best suited for rimming diamonds.
Palladium is an element capable of enhancing the anti-corrosion properties of even a metal that is resistant to aggressive media like titanium. The addition of palladium of only 1% increases the resistance of titanium to sulfuric and hydrochloric acids.
Paladium is the material from which most of the medals awarded by an eminent scientist, as well as athletes, are made.
History of the discovery of palladium
Palladium was discovered by an English doctor and chemist William Wollaston in 1803 while studying raw platinum brought from South America, in that part that is soluble in aqua regia. After dissolving the ore, Wollaston neutralized the acid with a solution of NaOH, and then precipitated platinum from the solution by the action of ammonium chloride NH4Cl (ammonium chloroplatinate precipitated). Then mercury cyanide was added to the solution, and palladium cyanide was formed. Pure palladium was isolated from cyanide by heating. Only a year later, Wollaston reported to the Royal Society that palladium and another new noble metal, rhodium, were found in raw platinum. Само название нового элемента — палладий (Palladium) Волластон произвел от названия малой планеты Паллады (Pallas), открытой незадолго до этого (1801) немецким астрономом Ольберсом.
Сорок шестой элемент благодаря ряду своих замечательных физико-химических свойств нашел широкое применение во многих областях науки и жизни. Так из палладия изготовляют некоторые виды лабораторной посуды, а также детали аппаратуры для разделения изотопов водорода. Весьма ценное применение находят сплавы палладия с другими металлами. For example, the alloys of the forty-sixth element with silver are used in communication equipment (making contacts). In thermostats and thermocouples used alloys of palladium with gold, platinum and rhodium. Certain palladium alloys are used in jewelry, dental practice (dentures), and even go into the manufacture of parts for pacemakers.
When applied to porcelain, asbestos and other carriers, palladium serves as a catalyst for a number of redox reactions, which is widely used in the synthesis of a number of organic compounds. Palladium catalyst is used to purify hydrogen from traces of oxygen, as well as oxygen from traces of hydrogen. Palladium chloride solution is an excellent signaling device for the presence of carbon monoxide in the air. Palladium coatings are applied to electrical contacts to prevent sparks and to increase their corrosion resistance (palladating).
In jewelry, palladium is used both as a component of alloys and by itself. In addition, the Bank of Russia minted from Palladium commemorative coins in very limited quantities. A small amount of palladium is consumed for medical purposes - the preparation of cytostatic drugs - in the form of complex compounds, similar to cis-platinum.
The honor of discovering palladium belongs to the Englishman William Hyde Wollaston, who isolated the raw metal from the raw platinum of South American mines in 1803. Who is this man whose name is a medal of pure palladium, annually awarded by the London Geological Society?
At the end of the eighteenth century, William Wollaston was one of many unknown London doctors practicing in poor working districts. A job that did not generate income could not arrange a smart and enterprising young man. In those days, the doctor had to have the skills not only of a physician, but also of owning an apothecary business, which in turn implied an excellent knowledge of chemistry. U.H. Wollaston turned out to be an excellent chemist - studying platinum, he invented a new method of making platinum dishes and adjusted its production. It is worth mentioning that in those years, platinum dishes for chemical laboratories were necessary, because the rush around scientific discoveries was the same as in the days of alchemists around the philosopher's stone. It is no coincidence at the turn of the XVIII and XIX centuries. open about 20 new chemical elements!
It is not surprising that the Englishman’s new enterprise began to bring him considerable income, sufficient to abandon unpromising medical practice. The products made by Wollaston were in demand far outside of foggy Albion, allowing the Englishman, without worrying about money, to engage in new chemical research. Improving the technique of refining and cleaning platinum from impurities, the chemist came to the idea of the possible existence of platinum-like metals.
Platinum, with which Wollaston had to work, was a by-product obtained by washing gold-bearing sands in a distant Colombian republic. In addition to gold, it contained mercury impurities, from which it was necessary to get rid of. He dissolved crude platinum in aqua regia, after which only platinum was precipitated from the solution — especially pure ammonia NH4Cl. It was then that Wollaston noted that the precipitated solution has a pink tint that impurities such as gold and mercury cannot give. Having added zinc to the colored solution, the chemist obtained a black precipitate, which he dried and then dissolved in aqua regia. It turned out that only part of the black powder dissolves. After dissolving the concentrate with water, Wollaston added potassium cyanide, as a result of which an abundant orange precipitate was formed, which, when heated, became gray. The gray precipitate was fused into a metal that was less mercury in specific gravity. By dissolving the resulting metal in nitric acid, Wollaston obtained a soluble part, which was palladium and insoluble, from which he extracted another platinoid, rhodium.
Rhodium has received its name from the Greek word "pink", because rhodium salts give the solution a pink color. As for palladium, Wollaston named it in honor of one astronomical discovery that occurred earlier. Shortly before the discovery of palladium and rhodium (in 1802), the German astronomer Olbers discovered a small planet in the solar system and in honor of the ancient Greek goddess of wisdom, Athena Pallas, called it Pallada.
What did Wollaston take after the discovery of a new element? He did not immediately declare this, but distributed an anonymous advertisement about the sale of new metal palladium in the Forster mineral merchant's shop. The message about the new noble metal - the "new silver" has interested many, including the chemist Richard Chenevix. Having a typical quick-tempered and irresistible Irish character, Chenevix wanted to expose the “fraudulent prank” and, ignoring the high price, bought a palladium ingot and began to analyze it.
Soon the Irishman suggested that the metal was not a new element at all, but was made of platinum by merging it with mercury according to the method of the Russian scientist A. A. Musin-Pushkin. This opinion of Chanewix hastened to express - first in a report read to members of the Royal Society of London, and then in the general press. In response, an anonymous advertising author announced that he was ready to pay £ 20 to anyone who could artificially prepare a new metal, according to the method proposed by Cheneviks. However, with all their efforts, other chemists, as well as Chenevix himself, could not find either mercury or platinum in palladium.
Only some time later, Wollaston declared officially that he was the author of the discovery of palladium and described the method for its production from raw platinum. At the same time, he announced the discovery and properties of another platinum metal, rhodium. In addition, he said that he was the anonymous seller of the new metal, who appointed an award for its artificial preparation.
William Heide Wollaston, a little-known London physician and world-renowned chemist who discovered palladium and rhodium, was such an interesting and extraordinary person.
Finding palladium in nature
Palladium is one of the rarest metals, its average concentration in the earth's crust is 1 -6 10-6% by weight, but this is two times more than the gold contained in the earth’s crust (5 ∙ 10-7%). William Wollaston had to extract palladium from the seeds of Colombian native platinum, the only known mineral containing palladium at that time. Nowadays, geochemists can name about 30 minerals that include this noble metal.
Like platinum, the forty-sixth element is found in its native form (unlike other platinoids), while it may contain impurities of other metals: platinum, gold, silver, and iridium. In appearance, it is quite difficult to distinguish it from native platinum, but it is much lighter and softer than it. Quite often, palladium itself is an impurity in native gold or platinum. So in the ores of Norilsk palladium platinum containing 40% of palladium was found, and in Brazil (the state of Minas Gerais) a very rare and poorly studied variety of native gold - palladium gold or porpetsite was found. In appearance, this mineral is very difficult to distinguish from pure gold, because it contains only 10% palladium.
About a third of the minerals containing palladium are little studied, some of them do not even have a name, this is due to the fact that the minerals of all the platinum metals form microinclusions in the ores and are difficult to access for research. One of these minerals is allopalladium. This silvery-white with a metallic luster mineral is very rare. Fully all the components of this mineral have not been identified until now, however, spectral analysis showed the content of mercury, platinum, ruthenium and copper in it. The most famous palladium minerals are palladium PdO, stannopalladite Pd3Sn2, stibiopalladite Pd3Sb (contains PtAs2 impurities), braggit (Pd, Pt, Ni) S (16-20% palladium), PdHg. The last of these minerals was found in 1925 in the diamond placers of British Guinea. Its composition was established by conventional chemical analysis: 34.8% Pd and 65.2% Hg.
The largest placer deposits of platinum metals (including palladium) are located in Russia - in the Urals. Among other countries rich in palladium are the USA (Alaska), Colombia and Australia.
However, the main supplier of the forty-sixth element of the steel is sulfide ore deposits of nickel and copper, in which palladium is a by-product of processing. After all, its content in such ores is three times more than platinum itself, not to mention its other satellites. Large deposits of such ores are located in Africa (Transvaal) and Canada. In our country, the richest deposits of copper-nickel ores are located in the Arctic (Norilsk, Talnakh).
Palladium is contained not only in the depths of our planet, as evidenced by the chemical analysis of the cosmic "guests". Thus, in iron meteorites, up to 7.7 grams of palladium per ton of matter, and in stone meteorites up to 3.5 grams. And on the Sun it was discovered simultaneously with helium in 1868
It is not surprising that, possessing the richest reserves of ores of platinum metals, Russia is one of the world's largest producers and exporters of palladium, as well as platinum, nickel and copper. The leadership in this field among Russian companies belongs to MMC Norilsk Nickel. Enterprises owned by the company are mining valuable metals in the Taimyr and Kola Peninsulas. The development of deposits of the Krasnoyarsk Territory. It is believed that the Taimyr Peninsula deposit is one of the richest in the world in terms of the palladium content in sulphide ores. For this reason, Norilsk Nickel is the owner of the largest palladium reserves in the world.
Interesting facts about palladium
It is known that palladium is often used by jewelers in alloys with other noble metals. So the alloys of the 583rd and 750th samples called “white gold” can contain from ten percent of palladium and more. In our country, the government officially established samples of palladium 500 and 850. These samples are most common in jewelry.
Another palladium sample that is popular is 950. This is due to the fact that wedding rings are made of metal, such a sample, as an alternative to white gold rings with a rhodium plated. The fact is that rhodium is quite quickly erased from the ring surface, and not everyone will be able to update the expensive coating annually. Palladium rings have exactly the same appearance as gold, but do not require annual renewal. In addition to standard palladium alloys, jewelry production sometimes uses decorative compounds of palladium with indium, forming a wide range of colors from golden to lilac. However, products made from such an alloy are very rare.
In 1988, for the first time, 25-ruble coins were minted from palladium in the series “The 1000th Anniversary of Old Russian Coinage, Literature, Architecture, the Baptism of Russia”. On the coin weighing 31.1 g of the highest 999 sample is a monument to Prince Vladimir Svyatoslavovich in Kiev. In Basel at the International Numismatic Exhibition, this series was recognized as the best program of the year, receiving the first prize for the quality of performance.
The issue of such coins was limited and did not last long, for this reason, coins have a high collectible value. The most valuable are the two series of coins (issue 1993-1994): “The first Russian world tour. 1803-1806 ”-“ The Hope Submarine ”with a portrait of I. F. Krusenstern,“ Neva ”Sloop (Yu.F. Lisyansky)”. Second series “First Russian Antarctic Expedition. 1819-1821 ”-“ Mirny sloop (MP Lazarev) ”,“ Vostok ”slope (F. F. Bellingshausen)”. Also presented are the coins of the series “Russia and World Culture” - “A. Rublev "," M. P. Mussorgsky ", coins of the series" Russian Ballet "and dedicated to the Russian monarchs.
There are a lot of awards and prizes in the world, which are presented to outstanding scientists. There is a William Hyde Wollaston Medal made of pure palladium. This award was established almost two centuries ago (1831) by the London Geological Society and, at the beginning, was made of gold. Only in 1846, the famous English metallurgist Johnson extracted pure palladium from Brazilian palladium gold, intended solely for the manufacture of this medal. Among those awarded the Wollaston Medal was Charles Darwin, and in 1943 the medal was awarded to Soviet scientist Academician Alexander Evgenjevich Fersman for his outstanding mineralogical and geochemical studies. Now this medal is kept in the State Historical Museum.
However, this is not the only palladium medal. The second, awarded for outstanding work in the field of electrochemistry and the theory of corrosion processes, was established by the American Electrochemical Society. In 1957, this award marked the works of the largest Soviet electrochemist, Academician A.I. Frumkin.
The merits of William Wollaston include not only the discovery of palladium (1803) and rhodium (1804), the receipt of the first pure platinum (1803), but also the discovery of ultraviolet radiation independent of I. Ritter. In addition, Wollaston designed a refractometer (1802) and a goniometer (1809).
Palladium industry in Russia appeared relatively late. Only in 1922, the State Refinery produced the first batch of Russian refined palladium. This was the beginning of the industrial production of palladium in our country.
It is known that palladium is able to enhance the anti-corrosion properties of even a metal that is resistant to aggressive media like titanium. The addition of palladium of only 1% increases the resistance of titanium to sulfuric and hydrochloric acids. So, for a year of being in hydrochloric acid, a plate made of a new alloy loses only 0.1 millimeter of its thickness, while pure titanium in the same period becomes 19 millimeters thin. Calcium chloride solution does not affect the alloy at all, but titanium annually loses up to two millimeters in an aggressive environment. What is the secret of such an alloy? The fact is that the acid interacts primarily with palladium and right there the surface of the second component of the alloy is covered with the thinnest oxide film - the part as it puts on a protective shirt. This phenomenon was called by scientists self-passivation (self-defense) of metals.
Another very valuable property of palladium is its relatively low price. So in the late sixties of the last century, it cost about five times less than platinum. Over time, the price of the forty-sixth element increased, but prices for other noble metals also increased. This quality of palladium makes it the most promising of all platinum metals, expanding the scope of its use.
Palladium, like other platinum metals, is an excellent catalyst. In his presence, many practically important reactions begin and take place at low temperatures, for example, the processes of hydrogenation of fats and cracking of oil. The processes of hydrogenation of many organic products palladium accelerates much better than such a proven catalyst, like nickel. The forty-sixth element is used as a catalyst in the production of acetylene, many pharmaceuticals, sulfuric, nitric, acetic acids, fertilizers, explosives, ammonia, chlorine, caustic soda, and other products of organic synthesis.
In chemical production equipment, the catalyst from palladium is most often used in the form of “mobile” (in the finely dispersed state, palladium, like all platinum metals, acquires a black color) or in the form of PdO oxide (in hydrogenation apparatuses). Since the seventies of the 20th century, palladium began to actively use the automobile industry in exhaust afterburning catalysts (neutralizers). By the way, neutralizers are necessary not only for cleaning the exhaust gases of automobiles, but also for cleaning any gas emissions, for example at CHP. Industrial plants of similar purpose are used in the USA, some EU countries and Japan.
Due to the fact that hydrogen actively diffuses through palladium, the latter is used for deep purification of hydrogen. Under low pressure, the gas is passed through palladium tubes closed on one side, heated to 600 ° C. Hydrogen quickly passes through palladium, and impurities (water vapor, hydrocarbons, oxygen, nitrogen) are trapped in the tubes. To reduce the cost of the process, not pure palladium is used, but its alloys with other metals (silver, yttrium).
We know that William Hyde Wollaston isolated palladium in the study of the latest methods of refining platinum. Dissolving raw platinum in aqua regia and precipitating only pure noble metal from the solution with ammonia, the chemist noted an unusual pink color of the solution. Coloring of this kind could not be explained by the presence of known impurities in the raw platinum, from which Wollaston concluded that there were some platinum metals in the samples of the ore studied by him.
Подействовав на полученный раствор необычного цвета цинком, английский химик получил осадок черного цвета, который он высушил и попытался повторно растворить в царской водке. Однако не весь порошок удалось растворить. Разведя этот раствор водой и добавив цианид калия (дабы избежать осаждения незначительных количеств платины, оставшейся в растворе), Уильям Волластон получил оранжевый осадок, который при нагревании приобрел серый цвет, а при сплавлении превратился в капельку металла, который ученый попытался растворить в азотной кислоте. Растворимая часть и являлась палладием.
Таким сложным и малопонятным языком сам ученый описывал открытие нового металла. Modern methods of obtaining pure palladium from natural raw materials, based on the separation of chemical compounds of platinum metals, are very complex and time consuming. Most firms and corporations engaged in refining are not located to share their production secrets. One can only say that the production of palladium is one of the stages of the processing of raw platinum and the production of platinum metals. The metal is produced according to the following scheme: from the filtrate remaining after the precipitation of (NH4) 2 [PtCl6], as a result of refining, the hardly soluble complex compound dichlorodiammine palladium [Pd (NH3) 2] Cl2 is obtained, it is purified from other metals by recrystallization from NH4Cl solution.
Sponge palladium alloyed in a high-frequency vacuum electric furnace. By restoring the solutions of the palladium salts, one obtains fine-crystalline palladium — palladium black.
Other refining methods are also used, in particular, based on the use of ion exchangers. It is known that in the mid-eighties of the last century, the annual extraction and production of palladium in western and developing countries was about 25-30 tons. From secondary raw materials palladium received no more than ten percent. At the same time, the USSR accounted for up to two thirds of the total world production of the precious metal. Nowadays (according to 2007 data), palladium production was 267 tons, of which Russia accounted for 141 tons, South Africa - 86 tons, the USA and Canada - 31 tons, other countries - 9 tons. From this statistics it is clear that production, like the extraction of the forty-sixth element, is increasing, and the role of the leader still remains with our country.
Products made from palladium are mainly produced by stamping and cold rolling. It is quite easy to get seamless pipes of the desired length and diameter from this metal. In addition, palladium is produced in ingots of 3000-3500 grams, as well as in the form of tapes, strips, foil, wire and other semi-finished products.
The metal trading market has seen a rapid growth in demand for palladium. Perhaps, in the near future, the existing supply on the market will already be lacking to meet the growing demand for the metal, with the result that the cost of palladium will rise even higher. Thus, palladium becomes the best investment for precious metals.
Palladium is a profitable investment
Since 2006, the demand for palladium has been growing on the metal trading market. It is possible that in the near future the existing supply on the market will already be lacking to satisfy the growing demand for metal, with the result that the price of palladium will rise even higher. Thus, palladium becomes the best investment for precious metals.
Palladium is a platinum group metal with unique properties, especially valuable for solving research and industrial problems. When palladium is added to titanium or chromium steel, their high ability to resist corrosion becomes almost absolute. Alloys with palladium are made of materials for the chemical, nuclear, oil refining industries.
Like other platinum group metals, palladium is an excellent catalyst. This property has found wide application in the automotive industry. Palladium has an amazing ability to absorb some gases, especially hydrogen. Because of this, it is beginning to be used in the development of fuel cells for hydrogen energy. With the development of technology, the consumption of platinum and palladium in the last half century has increased by more than 20 times. On top of that, palladium is also very beautiful and easy to process. It resembles platinum, but weighs less, has an even spellbinding brilliance. Extremely rare metal is mined from ores, which usually also contain gold, nickel, copper, and is sometimes found in its native form. The main raw material for its production are copper-nickel ores, in the processing of which palladium is a by-product.
Almost all the world reserves of ores containing platinum group metals belong to Russia and South Africa, and moreover, in South African ores there is more platinum, and in Russian - palladium. Small amounts of palladium are also found in the depths of Canada, the United States, Zimbabwe, China and Finland. The largest proven reserves of palladium are located beyond the Arctic Circle. According to the Norilsk Nickel company, proven and probable ore reserves in the deposits on the Taimyr Peninsula contain 62 million ounces of palladium and 16 million ounces of platinum. (Russia - Canada: competition in the market of non-ferrous metals).
Since the 1970s, the automobile industry has become the main area of application for platinum group metals. Platinum, palladium and rhodium are used in the manufacture of catalysts, which serve to reduce the toxicity of exhaust gases. For a long time for this they used almost exclusively platinum. Catalyst manufacturers such as Johnson Matthey, who had close ties with South African mining companies, were interested in this. They deliberately did not use cheaper palladium - it is, moreover, not so much from South Africa - and thus helped to maintain the high position of their suppliers, while they themselves remained, practically, monopolists.
The situation began to change in 1988, when Ford Motor Company (F) mastered the production of catalysts using palladium instead of platinum. By the mid-nineties, both metals were used to the same extent for the production of autocatalysts. With the tightening of environmental requirements, the consumption of platinum metals continues to grow. Over the past 5 years, the world's largest automakers have increased the use of palladium in car exhaust systems by 32%.
In the 1990s, palladium quickly began to force platinum out of the industry. If in 1990, platinum was used almost six times more than palladium in the production of autocatalysts, then in 1995 palladium began to prevail, and in 1999 the ratio was 4 to 1 in favor of palladium. The Palladium Decade (1990–1999) coincided with a period of widespread autocatalysts throughout the world. The corresponding increase in demand for platinum metals from the automotive industry was almost entirely covered by palladium, with relatively stable amounts of platinum used. In physical measurement, the use of PGM in autocatalysts for 10 years has increased almost 4 times, and palladium - 25 times!
In the first half of the 1990s, the increase in the demand for palladium was covered by the existing production capacity, and prices were kept at $ 100–150 / oz, i.e. 3 - 4 times lower than platinum. But a further increase in demand led to a shortage of palladium in the market since 1997, which led to a significant increase in prices. In 1999, the cost of palladium caught up with the cost of platinum, and in 2000 it became more expensive than platinum - a clear sign of market overheating. Manufacturers of autocatalysts were forced to reorient themselves to platinum, reducing purchases of palladium.
In recent years, the price gap between platinum and palladium is kept in the range of 3.5–5, and the normal price ratio (about 1 to 2) is still very far away.
Meanwhile, given the low price of palladium compared to platinum, the demand for palladium from autocatalyst manufacturers is growing again. According to Johnson Matthey, in 2008, the demand for palladium for use in autocatalysts increased by 0.9 tons to 142.3 tons.
In the field of beauty, palladium begins to restrict platinum. Palladium is beautiful in itself, and adds nobility to other metals: its small additives give gold a unique white tint, “white gold” serves as an excellent setting for precious stones. According to Fortunoff, the largest trading house and manufacturer of jewelry from New York, palladium products make up 10% of the jewelry market. According to Johnson Matthey, in 2008, the demand for palladium in the jewelry industry increased by 1.7 tons to 24.3 tons after falling two years in a row. Fortunoff spokeswoman Ruth Fortunoff says: “We definitely look forward to continued sales growth. People do not come specifically for decorations from palladium, but when they see prices and become acquainted with metal, they become its fans. ” The average price of a palladium wedding ring is about $ 600, while a ring made of platinum costs 2 times more. In an era of crisis, this becomes especially relevant.
A special role in the conjuncture of the market for precious metals begin to play exchange funds. Their shares, backed by precious metals, are listed on the stock exchange and are traded in the same way as corporate shares. Analysts believe that new funds will increase the demand for precious metals and attract additional investment.
Indeed, the creation of new exchange-traded funds, which themselves have become active purchasers of platinum, remains one of the main factors for a significant increase in the price of platinum. Since the properties and fields of application of palladium and platinum are in many respects the same, the markets for these metals are interrelated, which means that we can expect a similar reaction from the palladium market to the activities of the funds.
Such assumptions are confirmed by Stuart Flerlage (Stuart Flerlage) from the New York-based company NuWave Investment: "Platinum prices are rising higher and higher ... Perhaps we will have the same picture with valuable palladium." The creation of exchange-linked funds tied to the price of platinum may further spur demand for this metal, which will force more manufacturers and jewelers to turn their eyes to the more affordable palladium, says Michael Gambardella, an analyst at JPMorgan Chase & Co. (Jpm). “We are expecting to reduce the large price gap between the two metals,” adds Gambardella.
Opened by the English chemist William Wollaston in 1803. Wollaston isolated it from platinum ore brought from South America.
To isolate the element, Wollaston dissolved ore in aqua regia (aqua regia) neutralized the acid with NaOH solution, then precipitated platinum from the solution by the action of ammonium chloride NH4Cl (precipitated ammonium chloroplatinate). Then mercury cyanide was added to the solution, and palladium cyanide was formed. Pure palladium was isolated from cyanide by heating.
The extraction of palladium begins with the isolation and separation of platinum metals. From the obtained concentrated solution of platinum metal compounds, gold and platinum are precipitated first, then Pd (NH3)2Cl2. Further, palladium in the form of Pd (NH3)2Cl2 clear of impurities from other metals by recrystallization from NH solution4Cl. The resulting salt is calcined in a reducing atmosphere: Pd (NH3)2Cl2 = Pd + N2 + 2HCl + 2H2.
The prepared palladium powder is melted into ingots. By restoring the solutions of the palladium salts, one obtains fine-crystalline palladium — palladium black.
Properties and metal samples
Palladium is close in its characteristics to its neighbors in the periodic table. The properties of the metal allow it to be compared with silver - in appearance and weight, and with platinum - in chemical parameters. Pure metal has a silvery-white color and a density of just over 12 g / cm3. The latter physical property gives Pd an advantage in jewelry: massive palladium jewelry will weigh much lighter than platinum or gold.
In its pure form, Pd belongs to the number of soft metals, decorations from such material do not. Products from a pure element will not withstand even a small mechanical load. Jewelers use certain palladium samples in their work. What are they like? In Western countries, the 950 sample of a precious metal is quite common, in which 5% of ruthenium or copper is added to 95% of the main element. Nickel is also used as a component of a ligature capable of increasing the hardness of the alloy. In Russia, 500 and 850 samples of the metal have been approved; palladium is combined in them with silver and nickel. 850 sample can be made of Pd and copper. Resistance to wear from jewelry made of such alloys exceeds the characteristics of products made of gold and silver.
Pd as a metal is distinguished by ductility and malleability, thanks to which it can be processed in any of the following ways: cast in molds, solder, polish, engrave. The material is drawn into wire and can be rolled out in foil.
Palladium as an element is distinguished by the chemical inertness inherent in all platinoids, but among the metals of this group is the most active. Under normal natural conditions, it does not react with other substances, but dissolves in aqua regia, hot concentrated sulfuric and nitric acid. Pd can form compounds with chlorine, iodine, bromine, fluorine, sulfur and silicon. When heated in air, the metal is covered with an oxide film and tarnish; in normal operating conditions, the palladium products do not darken.
According to chemical properties, Pd is recognized by experts as a good catalyst; therefore, the main consumers of the element are the chemical and automotive industries.
Hydrogen Purification Edit
- since hydrogen diffuses very well through palladium, palladium is used for deep purification of hydrogen. Also, palladium is able to accumulate hydrogen extremely effectively reversibly. To save expensive palladium in the manufacture of membranes for the purification of hydrogen and the separation of hydrogen isotopes, alloys with other metals have been developed (the most efficient and economical alloy of palladium with yttrium).
Electrical contacts Edit
Palladium and palladium alloys are used in electronics - for sulfide-resistant coatings (advantage over silver).
In particular, palladium is constantly consumed for the production of high precision precision resistance resistors (military and aerospace equipment), including in the form of an alloy with tungsten (for example, PDV-20M).
In jewelry business Edit
- in alloys used in jewelry (for example, to produce gold-palladium alloy - the so-called “white gold”), in general, palladium, even in small amounts (1%), can dramatically change the color of gold to silver-white. The main alloys of palladium with silver in jewelry have a sample of 500 and 850 (the most technological and attractive).
Other uses of metallic palladium Edit
- in various precision mechanical tools
- Palladium is used for the manufacture of special chemical glassware, corrosion-resistant parts of high-precision measuring instruments.
- Medical instruments, parts of pacemakers, dentures, and some medicines are manufactured from Pd and its alloys.
- A certain amount of palladium is consumed to manufacture chemical equipment for the production of hydrofluoric acid (vessels, distillation cubes, pump parts, retorts).
Industrial application of metal
The extraction of palladium to date satisfies the demand on the market, which is mainly industrial. Pd application is distributed as follows:
- 70% - production of automotive catalysts,
- 10% - electronic industry,
- 5% - chemical industry
- 5% - medicine,
- 5% - investment
- 5% - jewelry and other areas of use.
The main part of the extracted metal is used for the production of automotive catalysts, which is why the demand for Pd depends on the economic situation in the engineering industry of a single consumer country. Neutralizers containing palladium are necessary in the production of cars of any brand for afterburning of exhaust gases. It was the use of Pd instead of platinum that was scarce in the 2000s that led to an increase in the quotes of this precious metal on world markets. An additional impetus was the decision of the EU to limit automobile emissions and tighten control over this area. Pd-containing catalysts are also needed to clean gas emissions from CHP plants.
The use of palladium in the chemical industry is extremely wide. Being an excellent catalyst, Pd is indispensable when carrying out processes of oil cracking and hydrogenation of fats. This chemical element as a catalyst is used in the production of acetylene, ammonia, chlorine, sulfuric and nitric acids, caustic soda, fertilizers and pharmaceuticals. In industry, palladium chloride is used as an indicator for the detection of trace amounts of carbon monoxide in gas mixtures.
The use of metal in the processes of deep purification of hydrogen, which actively diffuses through palladium, is widespread. Gas is passed under pressure through heated palladium tubes, as a result, hydrogen passes through the metal faster than other impurities, which are trapped in the tubes. Since the use of pure palladium for these purposes is expensive, in order to reduce production costs, Pd with silver or yttrium is used to purify hydrogen.
Pd and its alloys are used in the electronics industry. it creates coatings that are resistant to sulphides. Metal has found its use in the production of military, aerospace equipment and equipment for civilian use. The element is required when releasing reichords, as it is highly durable. Это свойства драгметалла отлично подходит для его использования в контактных группах. В гражданской аппаратуре Pd активно применялся в 80-х годах для контактов и струн советских контрольно-самопишущих машин и автоматических телефонных станций.
Где еще используется палладий? Он является компонентом керамических конденсаторов, известных всем радиолюбителям. The element is present in capacitors of type KM, characterized by high temperature stability of capacitance, which are present in any high-frequency radio and television equipment, mobile phones and computers. The presence of Pd in radio details attracts lovers of metal refining at home.
The metal has found application in other areas of industrial production, where it is used for various purposes: palladium is necessary for the process of making special chemical glassware, as well as corrosion-resistant parts of measuring instruments for special purposes. Pd is indispensable in the glass industry, where it is used in crucibles for melting glass.
Palladium in recent years is increasingly used in medicine. Metal and its alloys are spent on the production of parts of various medical devices and instruments. The simplest example of the use of Pd in this industry is the production of pacemakers, the individual parts of which are made from precisely this precious metal. Sometimes the element is used to obtain cytostatic drugs.
In medicine, the largest proportion of palladium is spent on the manufacture of dentures. The development of dental research and an increase in the associated demand for metal can increase demand and quotes for an element in the future - this factor is one of the potential causes of the increase in Pd value on exchanges.
Jewelry and investment
Jewelers use palladium as an independent precious metal, as well as a component of other precious alloys. Pd is a component of platinum ligature samples, and is almost always present as an element of gold alloys of the 585 and 750 samples. All the well-known and quite popular white gold today owes its hue to the addition of this particular chemical element. The precious metal itself is used in the manufacture of jewelry is also not in its pure form, in high samples in the alloy ligature there is ruthenium.
For global palladium mining, the demand of the jewelry industry is not critical. Even despite the policy of popularizing palladium jewels, consumer interest in them is small. Jewelry factories offer their customers traditional jewelry for women - earrings, rings, brooches, pendants, as well as men's seals, crosses and cufflinks. In recent years, precious metals are actively used in the collections of famous fashion designers, representing not only jewelery, but also stylish and unusual accessories: watches, lighters, pens, wallets.
Where else is precious metal used? Palladium, due to its noble origin, is among the investment instruments. Investing in precious metals can be done in different ways; among the available options for regular bank customers are the purchase of ingots and the opening of a metal account. OMS is conducted in grams of “virtual metal, so when you open it, you will not receive a single gram of Pd in your hands. But if you decide to buy an ingot, you can feel the weight of the metal in your hands.
Palladium in the market of precious metals is considered to be among the fundamental assets that can bring profit only in the long term. Most of the investment in the metal is futures contracts on the stock exchange, there is no point in buying palladium ingots in order to increase their money. For novice investors and ordinary banking customers, the easiest way is to open an impersonal account. Other peculiar investment tools directly related to Pd are commemorative coins. Coins of this metal are minted rarely and in limited quantities, therefore, it is impractical to consider them as a source of profit.