PGM SO SPECIAL
S.Narayana Moorthy

24042008

PGM GROUP

PGM are special  

   Palladium (Pd) 
  
  Iridium (Ir)   

  Rhodium (Rho) 

 Osmium (Os)   

  Ruthenium(Ru) 
  
  Trend   

  Special alloys  

   Applications
 

The mineral properties of precious and platinum group metals are unique and these characteristics figure in key applications. These find many applications in the automotive, jewelry, chemical, electronics, medical and glass sectors. The special properties are also exploited in the technological age and find increasing applications. Emerging technologies find many applications and will have an impact on the demand and supply as and when they become commercially significant. The dominance of passive capacitors and their role in miniature circuitry and the impact of environmental legislation and controls spreading to more and more countries are in this direction. The research and development of fuel cells as an alternative to fossil fuels is a pointer in this direction.

Why pg metals are so special?

Any commodity which has more demand than supply calls for attention. In the case of precious and pg metals, the demand has been consistently outstripping the supply over the past many years and the pointers are that this will continue to remain so.

1. The supply is limited to a few locations and countries.
2. Though extensive exploration and development work are in place, the physical supply position would improve only in a phased manner over the next few years.
3. The influencing factors.

There is a mass awareness on environmental issues and emission controls in automobile industry are being strictly enforced in Europe, Japan and USA. More countries including India and China, South Korea etc., are already having an implementation plan in place. Apart from the automobiles coming out with standards strictly adhering to emission controls, the switch to diesel vehicles is on the increase. Catalytic converters in the automotive industry are one of the major applications for the platinum group metal and the demand is expected to grow further. Platinum is extensively used in the automotive sector for catalytic converters and with strict enforcement of pollution controls find increasing demand in this sector.

The second major application is in the jewelry sector. The jewelry industry is already well supported by media and with new designs and fashions taking the front stage, platinum jewelry is already making inroads into the consumer market. The exposure to platinum jewelry is now on a very high note and the response is like never before. China has already overtaken traditional Japan as the major consumer of platinum jewelry and other countries are following suit. The jewelry sector is expected to play a major part in the coming years, with the population of upwardly mobile younger generation on the increase.

Platinum jewelry has now become both formal and informal and finds preference for everyday wear as well as special occasions like marriages etc. New designs, rich white color, anti-allergic properties are making platinum jewelry a popular choice, well supported by media coverage.

The special properties of the group find place in very specialized applications using super alloys, very hard cutting tools, instrument pivots and high- tech electronics. All these applications emerging with new technologies grow with innovations. Though the industrial sector has been using platinum group metals to a large extent but in specialized applications, technology is bringing about a major shift in the demand of platinum group metals apart from the main key applications like automotive and jewelry sectors.

Companies have taken these developments in their stride and extensive exploration programs are in place and some are in an advanced development stage. The production and supply schedules are already getting projected over the next 5 years and with the encouraging trend in the exploration programs the supply position is likely to improve further but with the applications also growing the demand supply deficit is likely to continue.

The metals platinum, palladium, rhodium, iridium, ruthenium and osmium are grouped under pg metals. Though platinum, palladium and rhodium are the important members of the group, the other metals combine to enhance properties and find use in specialized applications. The group metals mostly show similarity in their outstanding catalytic properties, high melting point, hardness and resistance to corrosion, and some metals in the group possess specific properties that find specialized applications.

Palladium

Palladium is silvery white in color. It is the least dense and also has the lowest melting point among other platinum group metals.

Distribution in the earth’s crust is mostly confined to Russia, North America. Current explorations could bring in Canada. Palladium is obtained as a by-product in South Africa.

Occurrence –palladium containing ore:

Russia is the major producer of palladium. South Africa meets about 33 percent of the world’s supply of palladium recovered as a by-product of platinum processing.

Applications Specific properties:

Auto catalyst Excellent catalytic properties
Jewelry Used along with platinum in the jewelry sector. Palladium is alloyed with gold to make white gold
Electronics Components
Dental Replacement to gold and base metals in certain cases
Rhodium is increasingly replacing palladium for auto- catalysts in Japan, and North America. Europe is also expected to follow this trend.
Palladium price could be the crucial factor in the long term prospects if the present trends are to be reversed and palladium captures back its market in the automobile sector.
This would depend on the supply stabilizing from Norilsk Nickel, Russia, policy changes in Gohkron, Russia, increased supplies from ongoing projects in South Africa and recycling reaching its threshold.

Iridium

Distribution in the earth’s crust is very low.
Commercial production of iridium is generally along with other platinum mineral as a byproduct of nickel/copper.
Occurrence of iridium-containing ore:

Very dense and rare, is a silver-white metal, used in platinum alloys. Adding 5 to 10 percent iridium to platinum alloys adds properties that are used in specific applications.

Application Specific properties:
Jewelry, pen points Hard and workable but becomes ductile at temperatures of 1200 ⁰C to 1500⁰C. Surgical pins and pivots Harder and stiffer and resistant to chemical attacks than soft platinum
Electrical contacts and sparking points Extremely hard metal with maximum corrosive resistance and very high melting point
Production of PVC Combined with ruthenium

An alloy containing 90 percent platinum and 10 percent iridium is used as the international standard kilogram.

Rhodium

Distribution in the earth’s crust is very low.
Commercial production of iridium is generally along with other platinum mineral as a by-product of nickel/copper.
Source for rhodium

Canada is the major source for rhodium.
Very dense and rare, is a silver-white metal, used in platinum alloys. Adding 5 to 10 percent iridium to platinum alloys adds properties that are used in specific applications.

Application Specific properties:

Auto catalyst Good catalyst. However rhodium is not used in diesel equipment
Thermo couples Alloyed with platinum for measuring high temperatures (platinum 90% and rhodium 10%)
Jewelry, optical instruments Silver white color and high reflectance to light
Uncertain supply position of palladium from Russia has created increased sourcing for rhodium in the automobile industry as a catalyst. Rhodium is finding use as an alternative to palladium except in diesel applications.
Inventory build-up at Japan and USA are influencing factors.
Upward trend in rhodium use:
Prominent Japan
Showing upward trend Europe, North America
Also China, South Korea

This upward trend for rhodium in automobile industry is expected to continue at least till 2005. The “Tier2” emission standards in USA expected to be in force in 2004 would further strengthen the demand of rhodium in the automotive industry

Osmium

Distribution in the earth’s crust is very low.
Obtained as a by-product along with other platinum group metals
Bluish white in color, osmium is brittle even at high temperatures. Osmium is processed to osmium powder as it is very difficult to work in a metallic state. Osmium is not very ductile but has a high melting point.
It is usually alloyed with other platinum group metals.
Osmium is very dense and usually alloyed with iridium to produce very hard alloys.

Applications Specific properties
Electrical contacts, pen tips, instrumental pivots Combined with other platinum group metals produces very hard alloys
Laboratory Finger printing, tissue stains for microscopic slides
Medical implants Alloyed with platinum (platinum 90% and osmium 10% ) for pace makers, valve replacements

Ruthenium

Distribution in the earth’s crust is very low.
Commercial production of ruthenium is generally along with other platinum mineral as a by-product of nickel/copper.

Ruthenium is a grayish-white metal, hard, brittle, shows poor oxidation resistance and almost unworkable in metallic state.

Occurrence:

Applications Specific Properties:

Electrical contact alloys and filaments, jewelry, pen nibs and instrument pivots
Ruthenium is used as a hardener and for severe wear-resistant properties In ceramic applications ruthenium is used to add color.
Alloys -apart from platinum group metals, ruthenium is commonly alloyed with cobalt, molybdenum, nickel, tungsten and others
Electro- chemical industry Components



Pointers

Meta Specific properties

Platinum, palladium Rather soft and ductile. Both metals and alloys can be worked hard or cold
Rhodium Can be worked hot initially, but cold working requires frequent annealing
Iridium Most corrosion resistant of all platinum group metals
Iridium ruthenium Can be worked hot with difficulty. Neither can be cold worked properly
Osmium Hardest of the platinum metal group and has the highest melting point. Limitation is ready oxidation

Alloys

Alloy Application