Facts About Palladium - Properties & Uses
Palladium is metal that is naturally white in color.
Palladium is one of the rarest metals on earth belonging to the Platinum Group of Metals also referred to as Noble Metals.
Palladium is a strong metal. It is highly resistant to corrosion, does not tarnish. Sources of this metal can be found in Australia, Brazil, Russia, Ethiopia, North America, South America, Canada and South Africa.
Discovery of Palladium
Palladium was discovered by William H. Wollaston, an English Chemist in 1803.
He discovered Palladium using the residues left by Platinum when it was dissolved in aqua regia and further isolated Palladium through a series of chemical reactions.
Aqua regia is a liquid made up of concentrated hydrochloric acid and nitric acid.
Properties of Palladium
Palladium is silvery white in color. It can be molded into any shape easily because it is malleable and ductile.
Palladium does not tarnish in the air, but it can tarnish to a small extent when exposed to moist air combined with sulphur.
Palladium can absorb 900 times its volume of hydrogen. It can keep expanding without breaking as it keeps absorbing hydrogen.
Palladium does not react with oxygen at room temperature, but can catch fire when ground into a powder.
Palladium is one of the rarest metal on earth because it is found in one to ten parts per trillion.
Use of Palladium in Jewelry
Palladium is lighter, whiter than platinum and does not tarnish. These properties make Palladium an excellent metal to use for making jewelry.
Since palladium is very light, the addition of large gemstones for decoration does not increase the overall weight of the jewelry.
Palladium alloys that are developed for jewelry have 95% palladium and 5% ruthenium. These alloys are called 950 palladium alloys.
950 palladium alloys that are used for jewelry making are white, malleable, lightweight, hypoallergenic, and easy to mold and polish.
What is White Gold?
Gold is alloyed with palladium to form white gold. In Europe, palladium is the standard metal used to produce white gold because it is hypoallergenic (skin friendly).
For an 18 carat, gold jewelry an alloy of 75% white gold and 15% palladium is used.
The addition of palladium to gold makes gold strong, increases the hardness, elasticity, and melting point of gold.
All the above-mentioned reasons make white gold an ideal metal to use for making jewelry.
Use of Palladium in Medicine
Small seeds of the radioactive isotope of palladium called Palladium-103 are used to treat certain types of cancer such as prostate cancer and breast cancer.
Palladium – 103 Brachytherapy
In this procedure, small seeds of Palladium-103 are permanently implanted into the center of the tumor. These seeds keep releasing small doses of radiation over a period of two months.
Depending on the type of seed selected the radiation lasts for two months to a year.
This procedure does not involve a stay at the hospital. The treatment is done under local anaesthesia, and the patient can go home after a few hours.
Use of Palladium in Water Treatment
Palladium acts as a catalyst in the process of purifying ground water. Contaminants such as halogenated volatile organic compounds also referred to as VOCs are present in ground water.
VOC’s are ground water pollutants in the form of hydrocarbons that are used as solvents, degreasers and in the manufacture of paints and adhesives. When these contaminants are not disposed of correctly they enter the groundwater and pollute it.
Water treatment methods that use palladium for purifying water destroy the contaminants.
The advantages of water treatment methods that use palladium are -
- very effective and can be done in a short time
- destroy the contaminants in water
- water need not be pumped out of the well to be treated
Disadvantages of water treatment methods that do not use palladium are -
- they do not destroy the contaminants
- they trap the contaminants in another medium
The problem with these water treatment methods is that the medium that has trapped the contaminants remains and has to be disposed of.
The use of palladium in the treatment of water is the best method as it destroys the contaminants instead of trapping it in a medium that still has to be disposed of.
The Royal Balancing Siphon Coffeemaker
The Royal Balancing Siphon Coffeemaker has a metal container that is made of palladium.
The Palladium Royal Siphon Coffeemaker is designed based on the model of the coffeemaker that was used in the mid-1800’s in France. This coffeemaker has a metal container and a glass carafe. A Bunsen burner is attached to the bottom of the metal container.
The metal container holds the water and the glass carafe is filled with ground coffee powder. The Bunsen burner heats the water in the metal carafe, and the boiling water is forced through the siphon and into the glass carafe that has the coffee powder.
The coffee is brewed in the glass carafe and once all the water is transferred into the glass carafe, the glass carafe tips the balance, the Bunsen burner is extinguished and the brew is transferred back to the metal container.
Watch the entire process in the video below!
Other Uses of Palladium
Palladium is used
- in catalytic converters in automobiles
- for hydrogenation, dehydrogenation
- making surgical instruments and electrical contacts
- purifying hydrogen
- water treatment
- widescreen televisions
- mobile phones
- interconnect cables for high-end audio systems
Palladium is a rare metal and has many uses. It is in great demand by many manufacturing industries. The constant supply of palladium is a big question mark considering the natural resources of palladium is very less.
© 2014 Nithya Venkat