TY - JOUR
T1 - Crystallization control for remediation of an FetO-rich CaO-SiO2-Al2O3-MgO EAF waste slag
AU - Jung, Sung Suk
AU - Sohn, Il
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/2/4
Y1 - 2014/2/4
N2 - In this work, the crystallization behavior of synthesized Fe tO-rich electric arc furnace (EAF) waste slags with a basicity range of 0.7 to 1.08 was investigated. Crystal growth in the melts was observed in situ using a confocal laser scanning microscope, and a delayed crystallization for higher-basicity samples was observed in the continuous cooling transformation and time temperature transformation diagrams. This result is likely due to the polymerization of the melt structure as a result of the increased number of network-forming FeO4 and AlO4 units, as suggested by Raman analysis. The complex incorporation of Al and Fe ions in the form of AlO4 and FeO4 tetrahedral units dominant in the melt structure at a higher basicity constrained the precipitation of a magnetic, nonstoichiometric, and Fe-rich MgAlFeO4 primary phase. The growth of this spinel phase caused a clear compositional separation from amorphous phase during isothermal cooling at 1473 K leading to a clear separation between the primary and amorphous phases, allowing an efficient magnetic separation of Fe compounds from the slag for effective remediation and recycling of synthesized EAF waste slags for use in higher value-added ordinary Portland cement.
AB - In this work, the crystallization behavior of synthesized Fe tO-rich electric arc furnace (EAF) waste slags with a basicity range of 0.7 to 1.08 was investigated. Crystal growth in the melts was observed in situ using a confocal laser scanning microscope, and a delayed crystallization for higher-basicity samples was observed in the continuous cooling transformation and time temperature transformation diagrams. This result is likely due to the polymerization of the melt structure as a result of the increased number of network-forming FeO4 and AlO4 units, as suggested by Raman analysis. The complex incorporation of Al and Fe ions in the form of AlO4 and FeO4 tetrahedral units dominant in the melt structure at a higher basicity constrained the precipitation of a magnetic, nonstoichiometric, and Fe-rich MgAlFeO4 primary phase. The growth of this spinel phase caused a clear compositional separation from amorphous phase during isothermal cooling at 1473 K leading to a clear separation between the primary and amorphous phases, allowing an efficient magnetic separation of Fe compounds from the slag for effective remediation and recycling of synthesized EAF waste slags for use in higher value-added ordinary Portland cement.
UR - http://www.scopus.com/inward/record.url?scp=84893615390&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84893615390&partnerID=8YFLogxK
U2 - 10.1021/es404277w
DO - 10.1021/es404277w
M3 - Article
C2 - 24410350
AN - SCOPUS:84893615390
VL - 48
SP - 1886
EP - 1892
JO - Environmental Science & Technology
JF - Environmental Science & Technology
SN - 0013-936X
IS - 3
ER -