{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,2]],"date-time":"2026-05-02T16:20:47Z","timestamp":1777738847120,"version":"3.51.4"},"reference-count":29,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2023,9,12]],"date-time":"2023-09-12T00:00:00Z","timestamp":1694476800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"UK Engineering and Physical Sciences Research Council","award":["EP\/W021013\/1"],"award-info":[{"award-number":["EP\/W021013\/1"]}]},{"name":"UK Engineering and Physical Sciences Research Council","award":["72207"],"award-info":[{"award-number":["72207"]}]},{"DOI":"10.13039\/501100006041","name":"Innovate UK","doi-asserted-by":"publisher","award":["EP\/W021013\/1"],"award-info":[{"award-number":["EP\/W021013\/1"]}],"id":[{"id":"10.13039\/501100006041","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100006041","name":"Innovate UK","doi-asserted-by":"publisher","award":["72207"],"award-info":[{"award-number":["72207"]}],"id":[{"id":"10.13039\/501100006041","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Recycling aluminium is essential for a circular economy, reducing the energy required and greenhouse gas emissions compared to extraction from virgin ore. A \u2018Twitch\u2019 waste stream is a mix of shredded wrought and cast aluminium. Wrought must be separated before recycling to prevent contamination from the impurities present in the cast. In this paper, we demonstrate magnetic induction spectroscopy (MIS) to classify wrought from cast aluminium. MIS measures the scattering of an oscillating magnetic field to characterise a material. The conductivity difference between cast and wrought makes it a promising choice for MIS. We first show how wrought can be classified on a laboratory system with 89.66% recovery and 94.96% purity. We then implement the first industrial MIS material recovery solution for sorting Twitch, combining our sensors with a commercial-scale separator system. The industrial system did not reflect the laboratory results. The analysis found three areas of reduced performance: (1) metal pieces correctly classified by one sensor were misclassified by adjacent sensors that only captured part of the metal; (2) the metal surface facing the sensor can produce different classification results; and (3) the choice of machine learning algorithm is significant with artificial neural networks producing the best results on unseen data.<\/jats:p>","DOI":"10.3390\/s23187837","type":"journal-article","created":{"date-parts":[[2023,9,12]],"date-time":"2023-09-12T21:41:12Z","timestamp":1694554872000},"page":"7837","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Classification of Shredded Aluminium Scrap Metal Using Magnetic Induction Spectroscopy"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7064-5395","authenticated-orcid":false,"given":"Kane C.","family":"Williams","sequence":"first","affiliation":[{"name":"Department of Electrical and Electroninc Engeering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-0180-4962","authenticated-orcid":false,"given":"Michael J.","family":"Mallaburn","sequence":"additional","affiliation":[{"name":"Department of Electrical and Electroninc Engeering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-3630-7604","authenticated-orcid":false,"given":"Martin","family":"Gagola","sequence":"additional","affiliation":[{"name":"Magnapower Equipment Ltd., A1, Harris Business Park, Hanbury Rd., Stoke Prior, Bromsgrove B60 4FG, UK"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6397-7431","authenticated-orcid":false,"given":"Michael D.","family":"O\u2019Toole","sequence":"additional","affiliation":[{"name":"Department of Electrical and Electroninc Engeering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-3703-1765","authenticated-orcid":false,"given":"Rob","family":"Jones","sequence":"additional","affiliation":[{"name":"Magnapower Equipment Ltd., A1, Harris Business Park, Hanbury Rd., Stoke Prior, Bromsgrove B60 4FG, UK"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5740-348X","authenticated-orcid":false,"given":"Anthony J.","family":"Peyton","sequence":"additional","affiliation":[{"name":"Department of Electrical and Electroninc Engeering, The University of Manchester, Oxford Road, Manchester M13 9PL, UK"}]}],"member":"1968","published-online":{"date-parts":[[2023,9,12]]},"reference":[{"key":"ref_1","unstructured":"Enkvist, P.-A., and Klevn\u00e4s, P. 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