Removal of Iron from Aluminum: A Review


Kawatra, S. K.


In this paper, the Fe-rich phases in and their detrimental effect on aluminum alloys are summarized. The existence of brittle platelet β-Fe-rich phases lowers the mechanical properties of aluminum alloys. The methods to neutralize the detrimental effect of iron are discussed. The use of high cooling rate, solution heat treatment, and addition of elements such as Mn, Cr, Be, Co, Mo, Ni, V, W, Cu, Sr, or the rare earth elements Y, Nd, La, and Ce are reported to modify the platelet Fe-rich phases in aluminum alloys. The mechanism of the modification is briefly described. Technologies to remove iron from aluminum are reviewed extensively. The precipitation and removal of Fe-rich phases (sludge) are discussed. The dense phases can be removed by methods such as gravitational separation, electromagnetic (EM) separation, and centrifuge. Other methods include electrolysis, electro-slag refining, fractional solidification, and fluxing refining. The expensive three-layer cell electrolysis process is the most successful technique to remove iron from aluminum so far.


Materials Science and Engineering

Keywords and Phrases

alloys; aluminum; modification; Centrifugation; Cerium alloys; Electrolysis; Iron alloys; Iron removal (water treatment); Manganese; Mechanical properties; Platelets; Rare earth elements; Refining; Slags; Strontium

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


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© 2012 Taylor & Francis, All rights reserved.

Publication Date

01 Jan 2012