The 9 most expensive metals in the world

Articles Aug 30, 2019 10:33

These are also the rarest metals on Earth.

Everyone thinks that gold and silver are the rarest metals today, but few people know that there are other metals that are much rarer and more expensive thanks to their special valuable uses.

What is the rarest metal on Earth?

9. Silver

Since ancient times, people have used silver in the exchange and trading of goods and facilities for many monetary systems. In addition, you can also be used to make jewelry, electronic components or produce mirrors that need high reflectivity. In particular, your halogen salt compounds have many applications such as silver nitrate, which is widely used in film storage technology; or silver iodide can collect clouds to create artificial rain.

The 9 most expensive metals in the world

Silver itself is not toxic but many of its salt compounds are very toxic and can cause cancer. Overall, silver has many benefits to human health such as extremely good bactericidal and germicidal properties. That's why the king's bowls, plates or chopsticks in the past were made of silver or many refrigeration equipment manufacturers like Toshiba, Panasonic, and Samsung applied nano silver technology in refrigerators and air conditioners. temperature, washing machine for antiseptic purpose.

8. Rhenium

Rhenium is one of the rarest metals currently in the Earth's crust. They are chemically similar to manganese and are obtained as a by-product of molybdenum and copper refining. The melting temperature of Rhenium is among the highest today, with only wolfram (3,695 K) and carbon (4,300-4,700 K) standing above it.

Normally Rhenium is in powder form but this element can be more concentrated by pressing and sintering in vacuum or hydrogen atmosphere. This process creates a solid product with a density over 90% of the specific density of this metal. When annealed this metal becomes very soft and can be bent or rolled into coils.

The 9 most expensive metals in the world

With such a high melting point, Rhenium is an important metal in the mechanical engineering industry of manufacturing high-temperature machines such as rocket engines and aircraft. Reni's alloy with tungsten is used to make electric filament bulbs, making thermoelectric batteries. Reni is also used as a catalyst in the refining and petrochemical industry.

Because it is a rare metal, the mining is very complicated and the money. It is known that the price of this metal increased rapidly in early 2008, from about 1,000 - 2,000 USD / kg in the period of 2003-2006 to over 10,000 USD / kg in February 2008.

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7. Paladium

Paladium is a silvery-white and soft metal that looks similar to platinum, discovered in 1803 by William Hyde Wollaston. At room temperature and atmospheric pressure, palladium can absorb hydrogen up to 900 times its volume, which makes palladium an effective and safe storage for hydrogen and hydrogen isotopes.

The 9 most expensive metals in the world

Palladium has the smallest specific gravity and lowest melting point among platinum group metals. It is soft and ductile when tempered and greatly strengthened and stiffened when cold worked. Palladium is also good at anti-tarnish, has good electrical conductivity and is highly resistant to chemical corrosion and good heat resistance.

The unique properties of palladium and platinum group metals (PGM for short) are palladium, platinum, rhodium, ruthenium, iridium and osmium) used in catalytic converters, in which they convert to 90% of the gases are toxic from car fumes.

6. Osmium

Osmium is one of the heaviest metals on Earth, it is the best heat-resistant of platinum group metals (PGM), its melting point is 3030o; In a solid state, osimi has a bluish white color similar to zinc and is stable to acids.

The 9 most expensive metals in the world

This metal is mainly used in stainless alloys used to seal pen nibs or tool pivots. In addition, Osimi works with Rutheni to treat bowel and ovarian cancer.

The price of Osmium is also not low, in 2010, 1kg of osimi cost about 12,700 USD.

5. Iridium

Iridium is one of the rarest elements on our planet. It is a hard, silvery-white metal of the platinum group (PGM), which is the best corrosion resistant metal, even at temperatures as high as 2000 ° C. Although only molten salts and certain halides will corrode solid iridium, fine iridium is more reactive and may even burn.

The 9 most expensive metals in the world

With special properties, Iridi plays an important role in the fields of medicine, electronics, automobiles as well as other consumer goods such as ballpoint pens, watches, and compasses.

For example:

With high corrosion resistance, Iridium is used in furnaces to recrystallize high temperature semiconductors, electrodes in chlorine production and radioactive isotope thermal generators used in spacecraft. space. In the automotive industry, iridium is used as spark plugs.

The average price of Iridium is now around 13,500 USD / kg and is found in South Africa.

4. Ruthenium

Ruthenium is a white, hard metal, has 4 crystalline variants and does not tarnish at normal temperature, but oxidizes easily in the air. Ruthenium dissolves in molten alkali, not corroded by acids but corroded by halides at high temperatures.

The 9 most expensive metals in the world

A small amount of ruthenium can increase platinum and palladium hardness, so Ruthenium is used in platinum and palladium alloys to make wear-resistant electrical contacts or 0.1% of ruthenium is added to titanium to improve the ability. Its corrosion resistance is up to hundreds of times.

Biologically, Rutheni can darken human skin, and can be carcinogenic and bioaccumulate in bones. However, their prices are quite expensive, about 14,500 USD / kg (2009).

3. Gold

People often have the saying: "Precious as gold" to refer to their value to life. Gold is a metallic yellow color when solid, but when cut finely, it is sometimes black, ruby ​​or purple; Soft, malleable, malleable, and light.

Gold combined with different metals will produce alloys of different colors, such as combining with copper for red, alloy with iron for green, alloy with aluminum for purple, and platinum. for white.

The 9 most expensive metals in the world

Gold does not react with most chemicals but is subject to aqua regia as well as cyanide solutions of alkali metals.

In the past, gold was mined to use for minting; Today it is widely used in medicine, helping to reduce the pain and swelling caused by rheumatism and tuberculosis but only its salts and isotopes can do it. In addition, gold is a good reflective material with electromagnetic radiation, so it is used as a protective coating for many artificial satellites, in infrared thermal protection plates and astronauts' hats.

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2. Platinum

Platinum is one of the rarest metals currently in the Earth's crust with an average distribution density of about 0.005 mg / kg, gray-white, hard to corrode, melting point up to 3215oF.

In pure form, platinum is silvery-white, shiny, malleable and malleable. It does not oxidize at any temperature, but can be corroded by halogens, cyanides, sulfur and caustic lye. Platin is insoluble in hydrochloric acid and nitric acid, but soluble in aqua regia.

The 9 most expensive metals in the world

As a heavy metal, it has a negative effect on health when exposed to its salts but due to its corrosion resistance, it is less toxic than other metals.

Platin is used in jewelry, laboratory equipment, electrodes, medical and dental equipment, chemical catalysts, and controls the level of car emissions. It is also hypoallergenic for human skin so you can safely use items from platium.

Platin is a scarce, precious and valuable material because annual production is only a few hundred tons. Therefore, its price is quite high, about 40,000 USD / kg.

1. Rhodium

Rhodium is a silvery-white, hard and durable metal, in a common metal state that does not produce oxide, even when heated. It is not corrosive to most acids: it is completely insoluble in nitric acid and only slightly soluble in aqua regia. The complete disintegration of rhodium in the form of a powder is only obtained in sulfuric acid.

The 9 most expensive metals in the world

Rhodium is mainly used as an alloying agent to harden platinum and palladium. These alloys are used in the furnace rollers and bushings to produce glass fibers, thermocouple components, aircraft spark plug electrodes and laboratory crucibles.

Because of the scarce supply, its price is very high, at one time in 2008 the price reached over 10,000 USD / oz. The annual production of rodium in the world is very small, and mainly comes from South Africa. By comparison, about 2,500 tons of gold are produced each year, while the annual Rodii output is only about 1% of the gold output, and the price is 1.5 times higher than the gold price.

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