XRF analyzers can be a valuable tool for scrap metal recyclers, improving profitability and preparing and sorting any metal to the correct grade chemistry.
By Peter Faulkner
In the modern global economy, scrap metal prices can fluctuate daily. Consequently, investing in a tool, like a handheld X-ray fluorescence (XRF) analyzer, to rapidly identify alloy grades can help you get the most value for your scrap metal recycling business. In this article, I will discuss some of the ways that scrap metal recyclers are using handheld XRF to increase their profitability as well as outline some features to look for when deciding which handheld XRF analyzer is right for your business.
Understanding XRF
Handheld XRF can be used to quantify the composition of a wide range of metal alloys, including aluminum, copper, ferrous and titanium alloys. It can also be used for cobalt and nickel alloys, so-called super alloys, and even solder. Although XRF can be used to detect elements magnesium and heavier on the periodic table, the list of commercially relevant alloying elements is much smaller. Handheld XRF can be used not only to quantify the base material (e.g., iron) along with the major alloying elements (e.g., chromium, nickel, or molybdenum), but it can also be used to accurately quantify tramp elements (e.g., tin, copper, or phosphorus).
Once the XRF analyzer determines the chemical composition of an alloy sample, it can use this information to compare the composition against a library of known commercial grades. Does your sample have chromium between 16 and 18 percent? Does your sample of molybdenum have less than 2 percent? By comparing against industry specifications (e.g., UNS, ASME, DIN, JIS, etc.), a definitive grade match can be determined.
How Handheld XRF Works
Briefly, the handheld XRF process can be broken down into four simple steps:
1. Emission: First, the analyzer emits X-rays.
2. Excitation: The X-rays hit the sample, causing it to fluoresce and send X-rays back to the analyzer.
3. Measurement: The detector measures the energy spectrum. This tells you which elements are present and the amount of each element present. It is important to note that XRF cannot be used to measure every element in the periodic table. In general, XRF analyzers can measure from magnesium to plutonium on the periodic table of elements.
4. Results: The analyzer processes the energy spectrum and displays the sample’s elemental composition. For metals, the composition can be matched to a specific grade.
The Value of XRF for Scrap Recyclers
XRF can help scrap metal recyclers improve their profitability by reducing the risk of shipping and charging out-of-specification materials to a furnace or smelter, which can lead to costly penalties. If this happens, you will likely face the costs of returning the shipment and re-sorting if the mix-up is discovered before payment. In addition, reprocessors and mills in many alloy applications are often unconcerned if all material is the same alloy type—just so long as the final melt chemistry is within specification. For this reason, obtaining a fast and accurate element chemistry is more important in the blending process without using expensive virgin metal.
The value of preparing and sorting any metal to the correct grade chemistry can show in the operating profit for your scrap recycling process. In the examples below, you can see just how rapidly the cost of a single XRF analyzer can be recovered.
High-Temperature Alloys: Stainless and Nickel Alloys
In most cases, nickel alloys, stainless steels, and other high-temperature alloys can be sorted from steel scrap with handheld XRF instruments. Measuring times are normally only a few seconds, which enables the operator to verify more pieces of high value scrap rapidly, increasing the ROI.
Aluminum Alloys
Basic sorting of aluminum provides a high separation of many alloys. For instance, mixing aluminum 1100 with 6061 or 6063 can lead to an out-of-specification magnesium concentration and may raise residual elements, such as copper and iron, beyond the specification limits. Ensuring a good, rapid magnesium reading will provide a good separation.
In this case, using a powerful XRF analyzer with lower limits of detection can help ensure that mixed loads are not shipped to smelters, reducing the cost of virgin magnesium at the smelter and minimizing the chance of penalties.
Calculating the True ROI of Handheld XRF for Scrap Metal Recycling
Scrap yards can be tough on high-tech instruments, like XRF analyzers. They can be exposed to rain and snow, hot or cold temperatures, and even the occasional drop. You need to be able to use your XRF analyzer in any condition and know that it is going to work. If your analyzer experiences a lot of downtime, it will take much longer to recover your total cost of ownership (TCO). Consequently, it is important to look for handheld XRF analyzers that are up to the challenge of these conditions. Choose an analyzer that is IP rated to withstand rain, dirt and dust as well as drop tested to U.S. Department of Defense standards (MIL-STD-810G) to help prevent repairs, maximize uptime and extend the analyzer’s life.
Another common source of damage to XRF analyzers is analyzing sharp objects, such as turnings. It helps to have an extra layer of protection from these costly repairs, such as a shutter that protects the X-ray detector.
When used for long periods of time in the heat, some XRF analyzers will overheat and need to be turned off to cool down. Be sure to pay attention to the analyzer’s temperature operating range at full duty cycle so you know your analyzer will keep working in hot or cold conditions. I recommend an analyzer with a temperature range of -10 °C to 50 °C (14 °F to 122 °F). While ruggedness is a critical factor, the analytical capabilities of your handheld XRF analyzer are also essential to ROI.
Images courtesy of Olympus.
Analytical Capabilities
There are many XRF analyzer models available at different price points, depending on the elements you need to analyze and the features you want. By only paying for what you need, you can minimize your total cost of ownership.
Keep in mind, pricing depends on where in the scrap collection process metals are sorted. In general, the closer the sorter is to the final smelter or revert facility within the supply chain, the more powerful—and more costly—the XRF analyzer will need to be.
Another potential cost associated with purchasing an XRF analyzer is the time and training it takes for new users to become proficient as well as how simple the instrument is to use. If the analyzer requires a lot of complex user inputs to generate a result, it is going to slow you down. To mitigate these factors, choose an analyzer that is easy to use.
Ease of Use
At the most basic level, you want to look for an XRF analyzer that has thoughtfully designed software and a clear, intuitive user interface. A general rule is that your XRF analyzer should be no more complicated to set up than your smartphone.
Another convenient feature is wireless connectivity, so users can connect their analyzer to the cloud for wireless data sharing. Look for a manufacturer that offers both wireless support for their analyzers as well as a cloud environment. With wireless connectivity, you can be alerted about new software updates and have the ability to update the instrument wirelessly. Also, make sure to choose an analyzer that has sufficient onboard storage, such as a 1 GB microSD™ card, as well as USB ports for easy data export. You can also store data, view data remotely, and share your analyzer’s screen with someone offsite or in an office.
Other available software-related benefits include:
• Remote troubleshooting
• Seamless data entry with an onboard barcode scanner—SKUs, lot numbers, and heat numbers.
• Customized data reports in multiple formats, such as spreadsheets and PDFs
• Real-time instrument health status
Conclusion
While XRF analyzers may seem to be an expensive investment, the examples discussed here demonstrate just how rapidly an XRF analyzer can more than pay for itself and improve a scrap recycler’s profitability. There are a wide range of handheld XRF analyzer manufacturers and models, so choosing the right one can be challenging. In addition to ensuring that your XRF analyzer has the power to solve the application you are using it for, it is also important to consider the analyzer’s ruggedness and ease of use to achieve a faster ROI. | WA
Peter Faulkner is Director of Market Development for Olympus. He has held sales and marketing positions within the analytical instrument field for more than 20 years. He received his BMet in metallurgy from the University of Sheffield, UK and has many years of experience within the metals and mining industries, including steel manufacturing, mining equipment, molten metal control sensors, and industrial gases prior to his work within the analytical instrument market. Peter can be reached at [email protected].
Olympus customers can connect their Vanta XRF analyzers to the Olympus Scientific Cloud™, where they have access to convenient fleet management tools and Apps that enhance the capabilities of the analyzer. Wireless connectivity also enables users to connect to the Vanta mobile app or to a local network. For more information, visit www.olympus-ims.com.