Posted by Metallix Refining on January 24, 2011
As we have discussed in previous posts, the platinum group metals(PGM) are the most rare, yet the most versatile metals in the precious metals family. PGM’s are well known for their resistance to corrosion, catalytic and stable electrical properties, and ability to withstand high temperatures.
While some PGM’s, specifically platinum, are well known for their use in fine jewelry, a more unknown but highly valued application is thermocouple wire. Thermocouple wire is also a key candidate for precious metal recycling.
What is a thermocouple?
According to Wikipedia, the definition of a “thermocouple” is:
“A junction between two different metals that produces a voltage related to a temperature difference.”
Essentially, thermocouples help to gauge and control temperatures, and also use heat to produce electricity. In industrial applications, thermocouples are used in the form of wire in furnaces that often heat steel and iron during manufacturing. Thermocouples are also used to measure temperature in kilns, gas turbine exhaust and diesel engines.
Types of Thermocouples
- Type B Thermocouples – B thermocouples include a platinum-rhodium alloy for each conductor, with one conductor containing 30 percent rhodium, and the other 6 percent. B thermocouples are typically the most stable, and can be used for temperatures up to 1800ºC.
- Type R Thermocouples – R thermocouples also contain a platinum-rhodium alloy, with one conductor containing 13 percent rhodium, and the other containing pure platinum. R thermocouples can withstand heat up to 1600ºC.
- Type S Thermocouples – S thermocouples use one pure platinum wire, and another that is 90 percent platinum and 10 percent rhodium. S thermocouples can withstand heat up to 1600ºC.
Precious Metal Value
Like many other industrial products containing precious metals, thermocouple wire is a key candidate for precious metal recycling. Thermocouple wire can be sold stripped, or with the plastic coating still intact. Your trusted precious metals buyer will remove the plastic coating and any other extraneous materials in order to test the raw wires for their precious metal type and content.
Like gold and silver, the prices of PGM metals have been on the rise in recent months, and are showing signs of continued growth. Businesses with scrap thermocouple wire can consider selling and recycling their materials, thus making additional profit for their business, reducing waste, and reducing the need for more mining.