Thanks to TOMRA’s new X-TRACT ™ unit

An aluminium recycling company and extrusion specialist, is the first company in the world to reap the benefits of X-TRACT™, the new sensor-based sorting solution from TOMRA Recycling Sorting. The X-TRACT™, TOMRA’s most advanced x-ray metals sorting unit, has enabled it to achieve 99% pure aluminium for use in secondary aluminium production. 

The new X-TRACT™ unit was installed in March 2021 at Alutrade’s Oldbury recycling plant in Birmingham which processes 42,000 tonnes of waste annually. The plant’s infeed material comprises metal extrusions from different types of post-consumer construction waste, such as windows and doors, as well as aluminium cans.

A combination of mechanical and sensor-based sorting 

When the infeed material arrives at the recycler's plant it is initially pre-shredded into smaller pieces of around one to two meters in length before being further shredded by a hammer mill. Magnets and eddy current separators are then used to separate the metals into ferrous and non-ferrous metals, removing any contaminants in preparation for the next sorting stage. 

Following magnetic separation, a combination of TOMRA sensor-based sorting units is used to process, sort and recover the target fraction of aluminium. Two of the earlier edition TOMRA X-TRACT™ units – which were installed in 2017 and 2018 respectively – are programmed to capture a larger aluminium fraction of >30mm and the new machine targets a smaller 10-30mm aluminium fraction, removing any heavy metal content from the aluminium. Both the earlier and new edition X-TRACT™ units sort metals based on the difference in atomic density, separating out any heavy metals.    

Meeting industry demand for premium recycled aluminium

Alutrade’s customers are remelts based all over the world who demand the highest purity grade of aluminium product for their remelting process as any heavy metal content affects the melt specifications.

Andrew Powell, Director at Alutrade LTD, explains: “Over the past five years, we have worked closely with TOMRA and our main customer, and have undertaken a lot of research to achieve this milestone of recovering an aluminium end fraction that meets the exceptionally high purity levels required to go straight into the remelt process. The smaller 10-30mm grain size captured by the new machine is 99% pure aluminium which means we can sell it on at a much higher price to our customers for use in the production of new aluminium products. What’s more, the new version of X-TRACT™ has opened up new international market opportunities for Alutrade as we can now source different infeed material, as well as sell on the ejected heavy metal products.”

The new X-TRACT™ – a superior solution 

Although the two earlier edition TOMRA X-TRACT™ units at the Oldbury plant allowed the recycler to capture the >30mm aluminium fraction, there were some restrictions on smaller fractions. However, thanks to a new x-ray sensor design, the new X-TRACT™ can separate fractions down to 5mm at even higher purity levels.

TOMRA’s new X-TRACT™ uses the same process of separating metals by atomic density as the earlier edition but offers far superior x-ray capabilities. The software-based solution can guarantee premium remelt quality recycled aluminium by ejecting the heavy metal contaminants.

The new generation X-TRACT™ unit boasts a number of new innovative features, including much faster sorting (up to 3.8 meters per second) and an increased capacity per meter width. A new high-acutance XRT sensor ensures sharper detection and shorter integration times for higher throughout, while a high-power (up to 1,000w) x-ray source is capable of processing multiple applications and grain sizes. An extended separation chamber reduces material loss by improving the trajectory of sorted objects and a new catcher hood ensures safer access and faster maintenance.

The recycler's X-TRACT™ unit is connected to TOMRA Insight, TOMRA’s secure, nearly real-time and on-demand cloud-based data monitoring platform. The platform enables customers to turn their sorters into connected devices and to transform sorting from an operational process into a strategic management tool. Generating high value data, TOMRA Insight helps to maximise plant throughput, boost sorting performance and optimise output quality.

Terence Keyworth, Segment Manager Metal Recycling North/East Europe, adds: “TOMRA and Alutrade have worked together for more than ten years so Alutrade’s Oldbury plant was an ideal plant for us to test and prove the capabilities of our new X-TRACT™. As the first prototype of this unit in an industrialised environment, it has been a very exciting project. We’re delighted that Alutrade has been so impressed with the sorting capabilities of this new technology and look forward to rolling out further installations over the coming months.”

A video case study of this project can be found on TOMRA’s YouTube channel here.