Acid leaching of alloys within the quaternary system Fe-Si-Ca-Al

• Author(s): Margarido, F. ; Figueiredo, M.O. ; Queiroz, A.M. ; Martins, J.P.
• Date: 1997
• Persistent ID: http://hdl.handle.net/10198/1858
• Origin: Biblioteca Digital do IPB
• Subject(s): Acid leaching refining; Synthesised alloys
• Document Type: Article
• Language: English

Description

Silicon with high purity and fine particle size can be produced by acid leaching of Fe-Si industrial alloys under the condition that they have adequate chemical composition and structural constitution. Such alloys contain phases that fall within the system Fe-Si-Ca-Al, where the quaternary phase Caalsifer, with aproximate formula (Fe0.8Al0.1 0.1) (Si0.8Ca0.2)2, is found along with several binary and ternary phases (Fe-Si, Ca-Si, Al-Fe-Si, Ca-Al-Si). With the purpose of optimizing the phase, constitution alloys were synthesized within the system Fe-Si-Ca-Al. The results of leaching experiments performed using HCl (150 and 220g/L) at constant temperature (T=102 1 C) and ordinary atmosphere indicate that the Caalsifer plus Al-Fe-Si phases should be maximized whereas the FeSi2 phases should be minimized, by controlling Al/Ca and Fe/Si concentration ratios in the synthesis process.