It has been 5 years since the official announcement of the success of Austin AI and Hydro joint research work that resulted in the installation of a pilot scale LIBS (Laser Induced Breakdown Spectroscopy) sensor sorter at Hydro´s R&D center in Bonn, Germany.

Short after the pilot system, the first production unit was installed in 2019, in Sweden and more followed in early 2020. Then, for known reason of the pandemic our business had slowed down for nearly two years.

Thanks to our presence at many international Shows in 2022 like ISRI, IFAT, IARC, Aluminium (Düsseldorf) our sales records have boosted up within the last few months. Another lesson that we learned when meeting with aluminium experts at the shows is that although the value of our LIBS Sensor Sorters are known, these experts are reluctant to add costs. This, in spite of our advertising claiming a fully loaded cost of under 2 cents per pound processed.

Let’s see some basics first. It is known that chemical composition is a key characteristic of aluminium products. Regarding the laboratory routine, spark optical emission spectrometry (EN14726) is the dedicated standard method for the accurate determination of the chemical composition of aluminium and its alloys. LIBS is an analogous analytical chemistry method having better precision and accuracy toward light elements. Also, due to its laser based generated signal, easier to implement into industrial process design.

At this juncture there is no surprise that with Austin AI’s LIBS sensor sorter one can achieve such a low detection limit as being able to pull a specific alloy, such as 6063. Moreover we have proven to a client an application where 6063 A2/A3/A4 are separated. Creating the sortation program for 6063, one can not only set a single alloying element but even all the eight (possible) together with their related (or any desired) concentration level. For example:

• 0.4% < Mg <0.9%,
• 0.2% < Si <0.6%,
• <0.1% Mn,
• <0.1% Zn,
• <0.35% Fe
• <0.1% Cu,

With the help of such a unique feature users can be confident about >95% purity of the extracted fraction that can even direct to smelters with no additional blending. This is a true green way to avert primary aluminium consumption to adjust scrap composition before its load into smelter.

We often have the question from recyclers: ‘Do we need XRT or XRF if we run a LIBS sensor sorter?’ XRT (X-ray Transmission), XRF (X-ray Fluorescence) and LIBS technology-based sensor sorters have their unique applications and advantages. Thus, the answer depends on the material what recyclers want to sort 

If one starts from Zorba, XRT is an ideal, fast and efficient technique to start with. XRT sorters are just like medical X-rays, sortation is based on a physical parameter, namely the density differences. Although, LIBS works well, XRT is the best way to separate ‘lights’ from ‘heavies’. Further step to gain distinguished groups from heavies can be XRF.

LIBS is a great choice when sortation begins with the ‘lights’ infeed. LIBS especially if stepwise silicon content is an issue and/or magnesium based alloys are of interest. 

The specialty of Austin AI LIBS is the either wrought or cast aluminium main groups to start with, the sorter can provide alloy specific sortation of both groups. Low concentration differences are well detected, like low Cu and Fe (<0.1%) cast aluminium alloy are already working applications.

Aerospace and car industry as well tend to dominate more and more lightweight magnesium based alloys we more often meet requests for magnesium based alloy sortation. This is another one of the key applications that we traditionally have been able to perform.

Finally, a brief overview Austin AI LIBS sensor sorter. The system is a patented LIBS based sensor sorter with the following advantages: 

1. There are no moving or wear parts outside of the air-jet diverter valves and the feeders. The system has the lowest cost of operation. 
2. The material is forced, by proprietary -shoot from below- engineering design, through a laser focal point to ensure each piece is subject to the LIBS analytical process. 
3. Each system is designed to a capacity of 6 process lanes—each lane capable of handling a single stream of material at nearly 3 m/sec. Each lane can be easily populated with a LIBS sensor module, giving a single system the capacity of 6 times normal single stream systems. Small footprint.
4. The laser used for the excitation process is fully solid state and of a class of laser used for metal cutting purposes. At a rep rate of 50,000 Hz, the system is capable of “burning” through most painted, oxidized, and otherwise contaminated scrap material. 
5. The proprietary, industrial spectrometer is designed for high performance in terms of alloy sorting. Achieving sub-class alloy sorting at reasonable purities and efficiencies are possible. 
6. Outstanding analytical performance. With our high performance, newly developed Gen#2 LIBS modules we can sort most of the critical alloying elements with as low threshold as 0.1%.

Available models: 

• The flagship model is the 6-Lane/6-Sensor design, offering high capacity and high-efficiency alloy-specific scrap sorting for secondary smelters and the recycling industry.
• A new, Single Lane LIBS-based sensor sorting system is ideal for R&D purposes and/or low capacity needs.
• Our LIBS technology-based WheelSorter system can assess large car parts, such as wheels with a throughput capacity of >10 TPH. No shredder processing is required! 

Across the entire aluminium industry, investing in recycling has currently become the preferred initiative to reduced carbon emissions in the smelting process. When you are aiming towards carbon neutrality, sustainability, green aluminium production, etc. consider Austin AI innovative LIBS technology as the final key. Truly, only melt the alloy that you wish to cast. It saves fuel and increases furnace turns per day. Given a fully loaded cost of under 2 cents a lb, it is true winner.