Metal identification has advanced quickly since the turn of the century. New technologies have helped transform the manufacturing industry from one where metal quality was unassured to a fast-moving market where metals can be identified with ease.
Manufacturing companies looking for metal quality assurance during the production process are benefiting from these new technologies for the verification of incoming materials, elimination of production mix-ups, and verification of outgoing products.
To profit from the latest market developments, Canadian manufacturers need to identify metal accurately, reliably, and with speed. Scrap workers looking to identify and recycle high-quality metals to be sold to manufacturers are also seeing benefits from these new technologies.
The Challenge: Accurate Grade ID
A common problem affecting the entire metal production process is inaccurately identifying varied metals – especially alloys containing light elements – from start to finish.
In the scrap industry, misidentified incoming materials can result in mixed loads and off-spec smelted products, culminating in load rejections by customers. In turn, this could then lead to manufacturers buying incorrect alloys, with off-spec final products reaching customers, and rejections once again occurring.
In addition, because of the work environment of this industry, any type of analytical equipment needs to be robust enough to withstand the harsh conditions and avoid the high cost of instrument repair.
Analyzers that can be used in the field are important, providing real-time, on-site analysis, which eliminates the need to depend on slower, expensive lab analysis. It is vital to speed up processes to gain an advantage over the competition, which still may be limited to analysis methods such as chemical spot testing and spark testing that require prolonged measurement times and provide less specific identification of the exact alloy grade.
Hand-held analyzers provide a rapid identification of metals in the field, improving on the time-consuming and costly process of larger analysis systems.
With the current slump in metal prices, accurate and fast identification is important to gain an advantage in the market. There are, however, challenges with many of the hand-held analyzers currently available on the Canadian market. For example, a number of analyzers are unable to rapidly identify light metal alloys such as magnesium and aluminum, or they only can do so after extended measurement times.
Moreover, not all of these hand-held analyzers are rugged enough to withstand harsh environments.
Finally, some analyzers require annual licensing fees, contributing to higher operating costs.
Some hand-held analyzers use laser-induced breakdown spectroscopy (LIBS) to identify light and heavy elements in a solid, liquid, or gas. Aluminum, magnesium, and beryllium all are examples of elements that can be identified using LIBS. Hand-held X-ray fluorescence (XRF) analyzers often have a problem with these materials.
The LIBS process works by creating a plasma plume at a high temperature using a laser source, which ablates a sample mass. As the sample cools, it emits light frequencies that are collected by a detector and transmitted for analysis and material identification.
Each element on the periodic table has a number of unique LIBS spectral peaks. These peaks are used to calculate the concentration of elements, such as metal alloy composition. Because LIBS is very sensitive to light atomic number elements and matrices, it can measure and identify light elements and metal alloys. Though traditionally a lab-based technique, LIBS now can be used in hand-held form with the development of compact spectrometers and solid-state microlasers.
An identification algorithm helps determine the alloy grade through comparisons with its library, displaying the result with the percentages of each element found within a material.
Hand-held LIBS also eliminates the emission of ionizing radiation found in XRF systems.
With manufacturers and scrap metal sorters constantly looking for new ways to profit in a crowded market where metal prices are currently low, new technologies can be a key differentiator for them. It is essential that higher returns be achieved to help build strong markets.Jen Lynch is marketing director, Rigaku Analytical Devices, 781-328-1024, www.rigakuanalytical.com.