Editor’s Note: This is Part 3 of a 6-Part Series on PGMs that runs on Tuesdays.
The Platinum Group Metals (PGMs) have several unique and valuable properties that make them indispensable for many industrial applications. The PGMs are extremely rare and are considered strategic metals or critical metals because they are necessary for many industrial and technological processes but are in short supply and have no adequate alternatives.
An estimated one-fifth to one fourth of everything we use either contains or is manufactured with platinum, the most valuable of the PGMs. Here’s a summary of just a few of the myriad industrial applications of PGMs; to learn more, visit the International Platinum Group Metals Association web site.
Thanks to their high temperature stability, melting points and corrosion resistance, platinum, rhodium, iridium and their alloys are used to make industrial crucibles, which are used in virtually every industrial process. High purity conditions are required for these processes and the PGMs, with their high temperature stability, do not contaminate the products being fabricated. Iridium is the preferred material for crucibles used in the production of high purity single crystals of various metal oxides, which have applications in laser technology as well as medical, petroleum, and security industries.
Platinum-rhodium catalysts are used in the manufacture of nitric acid, a key ingredient in fertilizer. Non-fertilizer applications include the production of explosive-grade ammonium nitrate, adipic acid for making nylon, and toluene diisocyanate for manufacturing polyurethane.
Iridium-ruthenium catalysts are part of the process that makes acetic acid, which has a very wide range of applications including cleaning, photography, fumigation, packaging, paints, adhesives and artificial fibers.
Platinum is also used in the production of paraxylene (PX), and a palladium catalyst is used in the production of purified terephthalic acid (PTA). Both PX and PTA are used to make polyethylene terephthalate (PET) an ingredient in plastics and polyester textiles.
- Ruthenium and iridium are used in the process that produces caustic soda, an ingredient in organic and inorganic chemicals, soaps, and detergents.
- Palladium is used in the manufacture of the raw materials to make nylon and synthetic rubber thanks to its hydrogen-absorbing qualities.
- Platinum catalysts are used in the production of silicones, high-octane gas, and petrochemical feedstocks, which are used to make plastics, synthetic rubber, and polyester fibers.
- Platinum and palladium are widely used in applications requiring stability at high temperatures such as jet engine and missile parts.
- Platinum and rhodium can be found in thermocouple temperature sensors which are used in the glass, steel, and semiconductor industries. Other platinum wire products may contain iridium, ruthenium and rhenium.
PGMs can be recovered from spent catalysts and other industrial products. Recycling PGMs from industry is much more successful than recovery from consumer electronics. Recycling efforts must be combined with careful elemental analysis of the recovered metal to determine its exact chemical composition and to ensure the metal is free from contaminants or hazardous materials. X-ray fluorescence (XRF) is a widely-used technology for this type of analysis. XRF a non-destructive analytical technique used to determine the elemental composition of materials. XRF analyzers determine the chemistry of a sample by measuring the fluorescent (or secondary) x-ray emitted from a sample when it is excited by a primary x-ray source. Because this fluorescence is unique to the elemental composition of the sample, XRF is an excellent technology for qualitative and quantitative analysis of the material composition.
Learn more about some of the XRF instruments available to improve industrial processes.