What is an XRF gun, and can you use them for catalytic converter evaluation?

An X-ray fluorescence (XRF) gun is a handheld device that determines the elemental composition of materials for quick and easy analysis. With a simple point-and-shoot technique, XRF guns are common in archaeology, geology & mining, jewelry, and product inspection fields. They work by measuring the fluorescent X-rays emitted from an object when it is excited by a primary X-ray source. But in the world of catalytic converter recycling, processors do not recommend using an XRF gun.

Are XRF guns useful to determine catalytic converter value?

The core of a catalytic converter is soaked in platinum group metals (PGMs), such as Platinum, Palladium, and Rhodium. Using an XRF gun will determine if those elements are present in the substrate but won’t give you the specific concentration. If you’re relying on XRF gun readings to determine the value of your converters, you’ll be surprised by the analysis your processor returns to you.

A great example is piling your converters in a lot and firing the XRF gun at the first converter laying on top. The PGM concentration of that particular converter will not be the same as another at the bottom of your lot. You’ll find yourself with inaccurate and disproportionate readings, and the value of your converters won’t be representative.

What to rely on for precise precious metal readings

Trusting that your processor has the right assay tools and procedures is the first step towards accurate analysis. Your processor must use an industry-proven methods and machines for precise and accurate readings.

Sample Preparation

Preparing a sample for analysis is important to determine the concentration of PGMs within scrap catalytic converters. When the converters are decanned, the ceramic centers are crushed, milled, and comingled. The end product of this process is a fine, homogenized powder, and a sample is sent to assay.

Reliable Analysis Machines

Relying on industry analysis machines, such as a benchtop XRF machine and Inductive Coupled Plasma Optical Emission Spectroscopy (ICP), will produce accurate assay results. Benchtop XRF machines work by measuring the secondary X-rays of a homogenized sample. ICP machines analyze the intensity of light emitted from a homogenized sample after it has been injected into plasma and atomized.

Machine Calibration

To ensure accurate and precise results, XRF and ICP spectrometers are calibrated and verified by trained and qualified personnel only. XRF and ICP methods for the analysis of PGMs in scrap catalytic converters are validated and approved. XRF Spectrometers are verified daily for proper calibration using a quality control standard. The ICP spectrometer is calibrated daily, and each sequence is verified using a quality control standard to assure good results.

Accurate and reliable results

Forget the XRF gun. Look for a processor that employs state-of-the-art technology and machinery – such as XRF benchtop and ICP – and works with the right team. Employees that are experts in their field have the experience and the training to deliver accurate assay results. They have the knowledge to collect and prepare samples correctly. They share the results with you because they understand that transparency is key.

Catalytic converter recyclers should not rely on XRF guns for converter evaluation because of the inaccuracy of the results. Instead, put the XRF gun in the drawer and trust the assay results your processor shares with you. You’ll be able to take those results to the bank and accurately value your converters.

Having access to resources to help you make the right market decisions when it comes to your converters is priceless. Visit PMR’s resource center for access to converter processing information.