Which analytical solutions exist for aluminium recycling?

A comprehensive report about aluminium analysis by optical emission spectrometry

Aluminium, a versatile metal with a wide range of industrial applications, has become an indispensable commodity in today's world. As the demand for this metal continues to soar, the importance of aluminium recycling has never been more critical, given its economic, environmental, and energy benefits. However, the production of specialised aluminium alloys, developed for specific applications in the aviation, transportation, medical, piping, defence, communications, and automotive sectors, poses a significant challenge due to the scarcity and high prices of their alloying elements, such as magnesium.

To address this challenge and ensure the quality and consistency of recycled aluminium alloys, advanced analytical solutions have become indispensable. These solutions provide an easy and reliable method of determining the elemental composition of incoming scrap streams, in-process grades, and finished products. By doing so, they help recyclers, refiners/remelters, producers, and end-users to make informed decisions and maintain the required specifications of their products.

In this article, we delve into the world of cutting-edge analytical solutions for aluminium recycling, with a particular focus on the revolutionary optical emission spectrometry (OES) technique. OES is a game-changing technology that offers unrivalled accuracy and speed in determining the elemental composition of aluminium and its alloys. We will explore the principles of OES, its remarkable advantages, its few limitations, and the practical applications of this groundbreaking technique in the context of aluminium recycling. By the end of this article, readers will have gained a comprehensive understanding of the latest and most advanced analytical solutions available for aluminium recycling, emphasising the unparalleled power of OES.

Types of analytical solutions

When it comes to analysing alloys in aluminium recycling, three instrumental categories reign supreme: XRF handhelds, OES mobiles, and OES stationary analysers.

XRF Handhelds

The XRF handheld is a portable X-ray fluorescence elemental analyser used for high throughput testing and spectrochemical analysis on the job site. It is a reliable, user-friendly tool that can analyse most alloys in only 2 seconds and identify alloys with challenging light elements such as aluminium, magnesium, and silicon in 7 seconds. The standard calibration captures alloys and precious metals for 16 matrices with 46 elements.

OES Mobile Metal Analysers (MMAs)

The battery-powered OES mobile metal analyser is a portable metal analyser that uses advanced optical emissions spectrometry technology. It can analyse elements such as carbon, sulphur, phosphorus, nitrogen, and boron as fast as an XRF, with many analyses taking only a few seconds.

SPECTROPORT

When handheld XRF instruments aren’t enough, this battery-powered portable metal analyser

applies more advanced optical emissions spectrometry (OES) technology — in a small, light unit as easy to use as a handheld. It accurately analyses elements such as carbon (C), sulfur (S), phosphorus (P), nitrogen (N) and boron (B). It’s as fast as an XRF, with many analyses taking only a few seconds. SPECTROPORT enables effortless point-and-shoot performance, to minimise operator intervention and decision-making. 

SPECTROTEST

The SPECTROTEST is an arc/spark OES mobile metal analyser that provides precise analysis without compromise. Its high-resolution optical system offers the industry's widest element range, including lithium and sodium, for a complete metal analysis on the spot. Users can choose from various quick-change sample probes for flexible point-and-shoot analysis, and it operates on battery power for up to 800 measurements on a single charge.

 OES Stationary Metal Analysers (SMAs)

SPECTROMAXx

The SPECTROMAXx is an arc/spark OES analyser that is the industry's best-selling and provides ultra-reliable metals analysis performance. It is ideal for both routine and precise elemental analyses from incoming materials to in-process testing to final inspection for outgoing quality.

 SPECTROLAB 

Spectrolab is SPECTRO's flagship instrument for metal analysis and provides superior OES performance for next-generation metal analysis. It offers ultimate elemental flexibility, covering 15 matrices, 68 methods, 65 elements, and 210 lines, with the quick installation of added elements and methods.

The choice of instrument depends on the specific application. It is necessary to consider the analytical tasks that the analyser needs to perform, the elements that need to be verified, detected, and/or measured, and the required accuracy levels. Additionally, it is important to evaluate the advantages and limitations of each instrument to determine which one is best suited for the job.

Rough sorting: handhelds.

Handheld XRF instruments are suitable for rough sorting tasks such as grouping and grading incoming aluminium scrap samples. They offer fast, accurate, and user-friendly solutions. For instance, the SPECTRO xSORT handheld analysers, weighing only 1.64 kilograms, have been specifically designed for on-site analysis without causing fatigue. They deliver timely and reliable results for most grades of aluminium and aluminium alloys, including wrought and cast alloys.

High-accuracy pre-sorting/sorting: MMAs.

For high-accuracy pre-sorting and sorting tasks in aluminium recycling, mobile metal analysers (MMAs) with sensitive OES technology offer better precision than handheld XRF units. These models are larger but still field deployable. For example, the SPECTROPORT analyser, weighing 19.8 kg, provides higher precision while maintaining on-site mobility.

XRF handhelds cannot detect lithium, but the SPECTROPORT MMA with OES optical technology can identify its presence in relatively high concentrations, like in 8000 series aluminium, for easy scrap sorting. For alloys containing trace amounts of lithium, the SPECTROTEST mobile metal analyser, weighing 33 kg, delivers near-laboratory-precision results on-site using OES optical technology.

Detection of impurities/production process monitoring: SMAs. 

Laboratory-level analysis is necessary for the most advanced analysis of incoming and outgoing materials in aluminium recycling, including impurity detection and process/melt monitoring. This can be achieved with a benchtop stationary metal analyser (SMA). To obtain analytical results of the highest quality, SPECTRO offers two SMAs: the popular high-performance stationary OES, SPECTROMAXx, and the even more powerful flagship stationary OES, SPECTROLAB. These SMAs provide low detection limits, high accuracy, and fast analysis.

Controlling Impurities

Controlling impurities is a critical aspect of aluminium recycling and production processes. Even a tiny amount of impurity in recycled aluminium can accumulate over time and harm the final product's quality. This is why ultra-precise analysis is necessary to detect impurities and prevent them from contaminating the newly produced alloys.

SPECTRO SMAs can measure tramp elements such as phosphorus, calcium, bismuth, and antimony, even at concentrations as low as parts per million (ppm). This means that users can ensure that impurities never exceed the 120-ppm total required for new alloy production. By implementing such precise analysis, manufacturers can guarantee that their products meet industry standards and are free from harmful contaminants.

Moreover, avoiding impurities is critical to ensuring the final product has the desired properties, such as good corrosion resistance and welding characteristics. These properties are vital for many applications, particularly in the aerospace and automotive industries, where the safety and reliability of the materials are paramount.

The importance of controlling impurities cannot be overstated, as it is critical to maintaining the quality and performance of aluminium alloys. SPECTRO's SMAs offer a reliable and precise solution for detecting impurities, thereby enabling manufacturers to produce high-quality alloys that meet the strictest industry standards. This ensures that the final product is of the highest quality, safe, and reliable, meeting the needs of the most demanding applications.

Optimising Aluminium Recycling with Advanced Analytical Equipment

Aluminium recycling is essential for sustainable manufacturing in the face of rising energy costs and environmental concerns. Accurate and reliable measurements of elemental concentrations are crucial for the effective recycling of aluminium. Whether using handheld, mobile, or stationary metal analysers, aluminium processors and end-users can ensure that impurities are kept at acceptable levels and that the resulting alloys meet the required specifications. With the right analytical tools, manufacturers can increase efficiency and add value to their products.

The use of SPECTRO’s range of XRF, OES handhelds, mobile metal analysers, and benchtop stationary metal analysers offers practical solutions to these challenges. These instruments help optimise processes, enhance product quality, and meet industry regulations by providing fast, precise, and reliable elemental analysis. The investment in advanced analytical equipment, coupled with process improvements, will help ensure the continued success of aluminium recycling, both economically and environmentally.

Interested in learning more about how SPECTRO's range of metal analysers can help improve your aluminium recycling process? Contact us today to speak with one of our experts and discover how our instruments can help you achieve your analytical goals. We look forward to hearing from you!