A CONCISE OF PGM HISTORY 🌟
POSTED BY ALICE
In the catalytic converter industry, we talk a lot about Platinum Group Metals - after all, for many of us, they are our livelihoods! We felt therefore, it was about time to write a history of these noble precious metals…
There are in total 6 Platinum Group Metals - platinum, palladium, rhodium, ruthenium, osmium, and iridium. They are grouped together because they share similar physical and chemical properties and tend to occur together in the same mineral deposits. The latter three occur in very small quantities and are used as hardening agents for platinum alloys and have some usages in making crucibles and heavy-duty electrical contacts. None are used in catalysts and therefore this article will concentrate on the main three - platinum, palladium, and rhodium.
The ancient Egyptians, more than 3,000 years ago, created gold jewelry that had traces of platinum, although this was unlikely to be intentional; it was more likely just a natural component of the ores the Egyptians imported from Nubia.
PGM in Egyptian ancient
Platinum has since been found in objects dating back to 700 BC - the famous Casket of Thebes, for example, is decorated with hieroglyphics in gold, silver, and platinum. And by 100 BC, native South Americans were using platinum to create metal nose rings and other items for ceremonial purposes.
During the 16th Century platinum nuggets were found mixed in with gold nuggets - some regarded it as a sort of “unripe” gold and for many years it had only nuisance value, as it was difficult to separate from the gold nuggets. Its only value at the time, it seems, was as a means of gold counterfeiting!
The Dawning of the Age of Metallurgy
The 18th Century was a time of great scientific discoveries in the world of metals, but platinum proved a tough challenge to scientists as they tried to understand and use the metal. Ironically, their difficulties were due to the very properties that make the metal suitable for so many applications - its high melting point and resistance to corrosion. As well, the presence of palladium and rhodium (yet to be formally identified) in the platinum deposits made analysis even more challenging. However, by the middle of the century, scientists had finally succeeded in melting platinum, firstly by adding arsenic then, more effectively, using recently discovered oxygen, and by the start of the 19th Century commercial quantities of platinum were being produced. Its main early uses were in the decoration of porcelain and ornaments
It was not until the early years of the 19th Century that palladium and rhodium were identified as separate mineral elements, both as a result of work being carried out on platinum. Palladium has the lowest melting point and is the least dense of the three, whilst rhodium a higher melting point and lower density than platinum. The early usage for all three precious metals was as a finish for jewelry and mirrors, due to their reflective properties and resistance to corrosion.
By the beginning of the 20th Century, platinum jewelry became a status symbol and was also popular in the 1920s and 30s when it became the preferred metal for engagement and wedding rings
Platinum wedding ring
During WW2 the USA declared platinum a strategic metal and its non-military use became illegal and it took several decades for platinum to regain its pre-war popularity as a jewelry metal.
During the 1960s, demand for platinum in jewelry experienced a spectacular rise in Japan, due to its appealing purity, color, prestige, and value, and by the end of the 20th Century had successfully penetrated the European, American, and Chinese markets.
In 1819, platinum was first found alloyed with gold in deposits in the Ural Mountains of Russia, and a short time later, found as a pure metal. By the early 1900s, this region of Russia produced approximately 95% of the world’s platinum supply.
In 1888, platinum was discovered in the nickel-copper ores of Ontario, Canada, and from the end of the First World War into the 1950s, Canada was the world's major source of supply.
In 1924, several nuggets of platinum were found in a riverbed in South Africa, and soon after two deposits, each of around 100 kilometers in length, were discovered. These became known as the Bushveld Igneous Complex and this area is now responsible for providing three-quarters of the world's platinum output.
The Technological Age
PGM mining grew continuously prior to World War 2, in response to the demand from industry. Platinum was used as a catalyst to increase the octane rating of gasoline in the petroleum industry and it played a prime role in the growing plastics industry. It was, though, the era of the autocatalyst that had a major impact on not only platinum but also palladium and rhodium and the automobile industry currently accounts for over 50% of the worldwide demand for PGMs.
1974 was the starting point, as concerns over pollution and the environment were starting to move into the public’s consciousness. In that year, the United States introduced legislation to reduce harmful vehicle emissions. As we all know, the use of catalysts for this purpose has spread worldwide and since their introduction, it is estimated that over 12 billion tonnes of pollution have been prevented from entering the earth's atmosphere. At the same time, this has put great strain on PGM resources and this led to the birth of the catalytic converter recycling industry.
Over time, as more stringent legislation has been introduced and different types of vehicles developed (for example, hybrids), the number of catalysts has increased substantially each with different percentages of PGMs, and the recycling industry that we are all part of has expanded rapidly, alongside technological developments that have improved the effectiveness and efficiency of PGM recovery. Today, it is estimated that roughly 1.2m. oz. (37tonnes) of Platinum, 2.2m. oz. (67tonnes) of Palladium and 272.000 oz. (7.7 tonnes) the worth of Rhodium is recycled from spent autocatalysts annually, in total worth just under 3.5 billion dollars…
The Future of PGM
The usefulness of the platinum group metals to the industry is based on their unique properties, including catalytic activity, high melting points, and chemical inertness over wide ranges of temperature.
Thus, apart from their role in petrochemicals, plastics, and catalytic converters, PGM’s are:
- essential components in computer hard drives to increase storage capacity
- used to coat electrodes
- active chemotherapy agents and an estimated half or more of all cancer patients who receive chemotherapy are treated with drugs containing platinum
- ideal material for pacemakers, stents, implantable defibrillators, and catheters
And, of course, PGM’s continue to play a role in investment and in the jewelry industry demand, then, is unlikely to decline, and yet the ability to source newly mined stock, both economically and environment-soundly, is open to serious question. Civilization, as we know it today, is highly dependent on the use of metals that exist only infinite amounts, and therefore must be used in a responsible way.
Recycling is a necessary and vital part of the process going forward, and, apart from the financial rewards that can be achieved, we all can play our part in providing a sustainable future for the planet.