TY - JOUR
T1 - Contribution of mineralogical phases on alkaline dissolution behavior of steelmaking slag
AU - Zhu, Zuoqiao
AU - Gao, Xu
AU - Ueda, Shigeru
AU - Kitamura, Shin ya
N1 - Funding Information:
The authors appreciate the financial support by the Iron & Steel Institute of Japan (ISIJ) from the research group on “The control of solidification structure of steelmaking slag for suppressing alkaline elution”, and from the 27th ISIJ Research Promotion Grant.
Publisher Copyright:
© 2019 ISIJ
PY - 2019
Y1 - 2019
N2 - To suppress alkaline elution from steelmaking slag through microstructure control, in this study, several mineralogical phases identified in industrial steelmaking slag were synthesized, and their dissolution behaviors were investigated. The results indicated that in addition to free CaO and free MgO, 2CaO·SiO2-3CaO·P2O5 (C2S–C3P) is another reason for alkaline elution from steelmaking. To suppress the amount of C2S–C3P in steelmaking slag, reducing the slag basicity by the compositional modification of slag at the hot stage was considered. To determine the optimum composition, the contribution of newly formed primary crystalline phases must be clarified. Some primary crystalline phases in the CaO–SiO2–FeOx–MgO–Al2O3 system were synthesized, and their dissolution behaviors were evaluated. The results indicated that the formation of α-CaO·SiO2 (α-CS), β-CaO·SiO2 (β-CS), 3CaO·2SiO2 (C3S2), 2CaO·MgO·2SiO2 (C2MS2), and 3CaO·MgO·2SiO2 (C3MS2) must be restrained in slag modification. Based on the results, a slag with multiple components and low basicity was synthesized, and the suppression of alkaline elution by reduction of slag basicity and microstructure control was confirmed. Moreover, a method to predict Ca dissolution and pH change during the dissolution of slag by the combination of each crystal phase was proposed.
AB - To suppress alkaline elution from steelmaking slag through microstructure control, in this study, several mineralogical phases identified in industrial steelmaking slag were synthesized, and their dissolution behaviors were investigated. The results indicated that in addition to free CaO and free MgO, 2CaO·SiO2-3CaO·P2O5 (C2S–C3P) is another reason for alkaline elution from steelmaking. To suppress the amount of C2S–C3P in steelmaking slag, reducing the slag basicity by the compositional modification of slag at the hot stage was considered. To determine the optimum composition, the contribution of newly formed primary crystalline phases must be clarified. Some primary crystalline phases in the CaO–SiO2–FeOx–MgO–Al2O3 system were synthesized, and their dissolution behaviors were evaluated. The results indicated that the formation of α-CaO·SiO2 (α-CS), β-CaO·SiO2 (β-CS), 3CaO·2SiO2 (C3S2), 2CaO·MgO·2SiO2 (C2MS2), and 3CaO·MgO·2SiO2 (C3MS2) must be restrained in slag modification. Based on the results, a slag with multiple components and low basicity was synthesized, and the suppression of alkaline elution by reduction of slag basicity and microstructure control was confirmed. Moreover, a method to predict Ca dissolution and pH change during the dissolution of slag by the combination of each crystal phase was proposed.
KW - Alkaline elution
KW - Mineralogical phase
KW - PH
KW - Primary crystal phase
KW - Steelmaking slag
UR - http://www.scopus.com/inward/record.url?scp=85075112001&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85075112001&partnerID=8YFLogxK
U2 - 10.2355/isijinternational.ISIJINT-2019-049
DO - 10.2355/isijinternational.ISIJINT-2019-049
M3 - Article
AN - SCOPUS:85075112001
SN - 0915-1559
VL - 59
SP - 1908
EP - 1916
JO - Transactions of the Iron and Steel Institute of Japan
JF - Transactions of the Iron and Steel Institute of Japan
IS - 10
ER -