• PDF / 924,797 Bytes
• 20 Pages / 593.972 x 792 pts Page_size
• 56 Downloads / 234 Views

DOWNLOAD

REPORT

---

metal pretreatments such as desiliconization, dephosphorization, and desulfurization are the indispensable operations for refining low or ultra-low

XUE-MIN YANG, Research Professor, is with the State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P.R. China. Contact e-mail: [email protected] JIN-YAN LI, Ph.D. Candidate and Joint-Training Student, is with the School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, P.R. China, and also with the Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, P.R. China. MENG ZHANG, formerly Master Degree Student, with the Institute of Process Engineering, Chinese Academy of Sciences, Beijing, is now with the Beijing Metallurgical Equipment Research & Design Institute Company Limited, China Metallurgical Group Corporation, Beijing 100029, P.R. China. GUO-MIN CHAI, formerly Ph.D. Candidate with the Institute of Process Engineering, Chinese Academy of Sciences, Beijing, is now with the Shanxi Taigang Stainless Steel Corporation Limited, No. 2 Steelmaking Plant, Taiyuan 030003, P.R. China. JIAN ZHANG, Professor Emeritus, is with the School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing. Manuscript submitted January 26, 2014. Article published online July 24, 2014. 2118—VOLUME 45B, DECEMBER 2014

phosphorus and sulfur steel products with high performances. Numerous studies[1–26] on simultaneous dephosphorization and desulfurization process of ironbased melts have been carried out all over the world since the 1970s. However, the study on its thermodynamics[5,18,20–22] is scarce compared with tremendous focus on kinetics.[1–4,6–17,19,23] It has been recognized[24,25] that controlling a reasonable oxygen potential at interface between the injected fluxes or added slags and iron-based melts is one of the key measures to ideally realize the aim of simultaneous dephosphorization and desulfurization of iron-based melts. The proposed ion and molecule coexistence theory (IMCT)[27–38] on metallurgical slags by Zhang[38] can be applied to elucidate the reaction mechanism of simultaneous dephosphorization and desulfurization process of iron-based melts because the defined mass action concentration Ni of structural units or ion couples in slags from the IMCT[27–38] can reliably be applied to represent reaction ability of components, like the traditionally applied activity aR,i of components relative to pure liquid or solid matters as standard state in classically metallurgical physicochemistry. The CaOFetO-Al2O3 type slag system was recommended by Banya et al.[20] to apply in simultaneous dephosphorization METALLURGICAL AND MATERIALS TRANSACTIONS B

and desulfurization process of iron-based melts. The distribution equilibria of oxygen, phosphorus, and sulfur between CaO-FeO-Fe2O3-Al2O3-P2O5 and liquid iron were experimentally measured by Ban-ya et al.[20] The slag system used by Ban-ya et