Dissolution Behavior of Lime with Different Properties into Converter Slag

China’s 2022 crude steel production soared to an impressive 1.018 billion tons, and steel slag constituted approximately 10% to 15% of this massive output. However, a notable hindrance to the comprehensive utilization of steel slag arises from the fact that it contains 10% to 20% of free calcium oxi...

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Main Authors: Mengxu Zhang, Jianli Li, Cao Jia, Yue Yu
Format: Article
Language:English
Published: MDPI AG 2023-09-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/16/19/6487
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author Mengxu Zhang
Jianli Li
Cao Jia
Yue Yu
author_facet Mengxu Zhang
Jianli Li
Cao Jia
Yue Yu
author_sort Mengxu Zhang
collection DOAJ
description China’s 2022 crude steel production soared to an impressive 1.018 billion tons, and steel slag constituted approximately 10% to 15% of this massive output. However, a notable hindrance to the comprehensive utilization of steel slag arises from the fact that it contains 10% to 20% of free calcium oxide (f-CaO), resulting in volume instability. To address this challenge, our study delved into the dynamic transformation of the interface between lime and slag, as well as the fluctuations in the dissolution rate of lime. An Electron Probe Micro Analyzer, equipped with an energy-dispersive spectrometer, was employed for the analysis. Our findings revealed that the configuration of the reaction interface between quicklime and slag underwent alterations throughout various phases of converter smelting. At a temperature of 1400 °C, several significant transformations occurred, including the formation of a CaO-FeO solid solution, (Ca, Mg, Fe) olivine, and low-melting point (Ca, Mg) silicate minerals. With the gradual reduction in FeO content, a robust and high-melting 2CaO·SiO<sub>2</sub> layer emerged, generated through the interaction between CaO and (Ca, Mg, Fe) olivine. Furthermore, for lime with a particle size of 20 mm and a calcination rate of 0%, the thickest layer of 2CaO·SiO<sub>2</sub> was observed after 120 s of dissolution in slag A2 at 1400 °C. Overall, the dissolution rates of lime with different particle sizes in slag A1 to A4 showed a gradual increase. On the other hand, the dissolution rates of lime with different calcination rates in slag A1 to A4 exhibited an initial increase, followed by a decrease, and then another increase. The formation of a high-melting point and continuous dense 2CaO·SiO<sub>2</sub> layer during the dissolution process hindered the mass transfer between lime and slag.
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spelling doaj.art-e24fa46ec7af432e91dcf4713af4f8192023-11-19T14:40:32ZengMDPI AGMaterials1996-19442023-09-011619648710.3390/ma16196487Dissolution Behavior of Lime with Different Properties into Converter SlagMengxu Zhang0Jianli Li1Cao Jia2Yue Yu3The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, ChinaThe State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, ChinaThe State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, ChinaThe State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, ChinaChina’s 2022 crude steel production soared to an impressive 1.018 billion tons, and steel slag constituted approximately 10% to 15% of this massive output. However, a notable hindrance to the comprehensive utilization of steel slag arises from the fact that it contains 10% to 20% of free calcium oxide (f-CaO), resulting in volume instability. To address this challenge, our study delved into the dynamic transformation of the interface between lime and slag, as well as the fluctuations in the dissolution rate of lime. An Electron Probe Micro Analyzer, equipped with an energy-dispersive spectrometer, was employed for the analysis. Our findings revealed that the configuration of the reaction interface between quicklime and slag underwent alterations throughout various phases of converter smelting. At a temperature of 1400 °C, several significant transformations occurred, including the formation of a CaO-FeO solid solution, (Ca, Mg, Fe) olivine, and low-melting point (Ca, Mg) silicate minerals. With the gradual reduction in FeO content, a robust and high-melting 2CaO·SiO<sub>2</sub> layer emerged, generated through the interaction between CaO and (Ca, Mg, Fe) olivine. Furthermore, for lime with a particle size of 20 mm and a calcination rate of 0%, the thickest layer of 2CaO·SiO<sub>2</sub> was observed after 120 s of dissolution in slag A2 at 1400 °C. Overall, the dissolution rates of lime with different particle sizes in slag A1 to A4 showed a gradual increase. On the other hand, the dissolution rates of lime with different calcination rates in slag A1 to A4 exhibited an initial increase, followed by a decrease, and then another increase. The formation of a high-melting point and continuous dense 2CaO·SiO<sub>2</sub> layer during the dissolution process hindered the mass transfer between lime and slag.https://www.mdpi.com/1996-1944/16/19/6487properties of quicklimereaction interface2CaO·SiO<sub>2</sub>dissolution ratemass transfer
spellingShingle Mengxu Zhang
Jianli Li
Cao Jia
Yue Yu
Dissolution Behavior of Lime with Different Properties into Converter Slag
Materials
properties of quicklime
reaction interface
2CaO·SiO<sub>2</sub>
dissolution rate
mass transfer
title Dissolution Behavior of Lime with Different Properties into Converter Slag
title_full Dissolution Behavior of Lime with Different Properties into Converter Slag
title_fullStr Dissolution Behavior of Lime with Different Properties into Converter Slag
title_full_unstemmed Dissolution Behavior of Lime with Different Properties into Converter Slag
title_short Dissolution Behavior of Lime with Different Properties into Converter Slag
title_sort dissolution behavior of lime with different properties into converter slag
topic properties of quicklime
reaction interface
2CaO·SiO<sub>2</sub>
dissolution rate
mass transfer
url https://www.mdpi.com/1996-1944/16/19/6487
work_keys_str_mv AT mengxuzhang dissolutionbehavioroflimewithdifferentpropertiesintoconverterslag
AT jianlili dissolutionbehavioroflimewithdifferentpropertiesintoconverterslag
AT caojia dissolutionbehavioroflimewithdifferentpropertiesintoconverterslag
AT yueyu dissolutionbehavioroflimewithdifferentpropertiesintoconverterslag