Refiners and Smelters of PGMs (Platinum Group Metals)
Platinum group metals are extremely important to recover because one-quarter of all manufactured goods either contain a PGM or a PGM played a key role in its production. The six PGMs are platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), osmium (Os) and iridium (Ir). To recover these PGMs from end-of-life materials there are several key steps but two commonly discussed terms, refining and smelting. Both are different and are important in the recovery of PGMs from many different applications including some automotive components like your catalytic converters, oxygen sensors, spark plugs, and more.
Refining vs Smelting Auto Catalyst
Refiner:
Platinum group metals (PGM) are refined using highly sophisticated chemical methods that are particular to their composition. The use of the right compounds, as well as the chemical reactions that occur, makes it easier to separate PGM from other elements that may be attached. Refining is the process of purifying an impure metal in metallurgy. It differs from other processes like smelting and calcining in that those two involve a chemical change to the raw material, whereas refining usually results in a final material that is chemically identical to the original one, only purer. There are several wet chemistry refiners that are considered industry leaders in the refining of auto catalysts. Johnson-Matthey, Heraeus, BASF, and UMICORE are the global leaders.
Processor:
Some companies claim to be refiners however they are not equipped to act as refiners. True refiners operate as wet chemistry refiners while these “refiners” are actually processors that would be De-canning, ball milling to homogenize, and extracting samples to test the catalyst and purchase your catalyst. Platinum group metals refining requires a series of complex chemical separation techniques that these companies are not equipped to conduct. They will receive either your whole cat or a de-canned auto catalyst.
Smelter:
Smelting is the process of using heat to remove a base metal from ore. It is an extractive metallurgy technique. Base metals like Silver, iron, copper, and even PGMs, are extracted from their ores using this method. The major smelters sell to the industry leading refining companies we mentioned, and they concentrate on platinum, palladium, and rhodium produced from their furnace operations because they are smelters. All catalyst from converters is considered low grade PGM material and must be smelted into an ingot. This vital upgrade step increases the PGM concentration to the point that it becomes an acceptable feedstock for the wet chemistry process of refiners.
Some processors who claim to be refiners have positioned themselves between the individual catalytic converter collectors and the smelter due to the limited volume individual suppliers can produce. These companies have additional overhead and expenses to account for when purchasing catalytic converters. Every processor needs a smelter and every smelter needs a refiner. All of these play a significant role in recovering the PGMs bringing them back into the circular economy.
References:
1.Schwenk, Edmund. “Companies That Are Not Refiners | PGM Recovery Systems Info.” PGM Recovery Systems, Pgmrecoverysystems.com, 24 August. 2018, https://pgmrecoverysystems.com/companies-that-are-not-refiners/.
2. Thethwayo, Bongephiwe Mpilonhle. “Extraction Of Platinum Group Metals | IntechOpen.” Extraction Of Platinum Group Metals | IntechOpen, Www.intechopen.com, 21 February. 2018, https://www.intechopen.com/chapters/58968.
3. – Coderman, Nikola Jovanovic. “The Role Of Platinum Group Metals In Modern Applications – Materials And Engineering Resources – Matmatch.” Materials And Engineering Resources – Matmatch – Get the Latest in Materials Science and Engineering News, Educational Content And Material Use Cases., Matmatch.com, 1 August. 2019, https://matmatch.com/resources/blog/platinum-group-metals-modern-applications/.
4. “PAMP | Platinum Group Metals.” PAMP | Platinum Group Metals, Www.pamp.com, https://www.pamp.com/refinery/platinumgom#:~:text=The%20refining%20of%20platinum%20group,of%20PGM%20from%20other%20elements.
5.“Smelting | Definition & Facts.” Encyclopedia Britannica, Www.britannica.com, https://www.britannica.com/technology/smelting.
