Recycling of Metals
AimsBefore you startIntroductionWhat metals can be recycled?Processing before recyclingPhysical sorting – The Eddy current separation method Tin can processing Copper in motorsRecycling processes and issuesContaminants in aluminium alloysThe Ellingham diagram in removal of contaminantsAutomobile recyclingSummaryQuestionsGoing furtherTLP creditsTLP contentsShow all contentViewing and downloading resourcesAbout the TLPsTerms of useFeedbackCredits Print this page
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Processing before recycling
Metals are used in a wide variety of applications. They will therefore be in a wide variety of states when they are sent for recycling.
Sorting and processing of metal scrap is essential, because when melted, mixtures of metals may become alloys. Without careful separation the quality of the final product will be reduced. This issue is explored and explained later in this TLP.
In this section, four examples of sorting and processing are investigated:–
- the Eddy current separation method (electromagnetic induction)
- the leaching and electrolysis of tin from steel cans (electrochemistry)
- the theoretical cryogenic separation of copper from steel motors (ductile-brittle transition)
- the chemical oxidation of tramp elements from molten steel scrap (Ellingham diagram)
Phase diagrams are also used to illustrate the problems that can occur when not all contaminants are removed.