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2011-Sustainable Industrial Processing Summit
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| Editors: | Florian K |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2012 |
| Pages: | 828 pages |
| ISBN: | 978-0-9879917-0-6 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
Structural Analysis Around Boron And Phosphorous In The CaO-SiO2 Based Slag By MAS-NMR
Motohiro Sakamoto1; Yutaka Yanaba2; Kazuki Morita1;1THE UNIVERSITY OF TOKYO, Tokyo, Japan; 2INSTITUTE OF INDUSTRIAL SCIENCE, THE UNIVERSITY OF, Tokyo, Japan;
Type of Paper: Regular
Id Paper: 395
Topic: 4
Abstract:
CaO-SiO2 based slag is commonly employed in the steel making industry and is also a candidate for refining molten silicon. In order to understand the mechanism of impurity removal from metal phase to slag phase at the slag/metal interface, it is important to elucidate the local structure and behavior of the impurities in molten slag.In the present paper, the local structure of 11B in the CaO-SiO2-BO1.5 system and 31P and 29Si in the CaO-SiO2-PO2.5 system were observed using the Magic Angle Spinning – Nuclear Magnetic Resonance (MAS-NMR) and their composition and basicity dependences have been investigated.In the CaO-SiO2-BO1.5 system, the boron existed as trigonal boron species (BO3 groups, denoted here as [3]B) as well as tetrahedral boron species (BO4 groups, [4]B). In the studied composition, the fraction of [4]B to total boron species decreased with increasing the basicity. On the other hand, in the CaO-SiO2-PO2.5 slag system, phosphorous existed as monophosphate ion, (PO43-), and this phosphate ion structure was independent of the slag composition and basicity. However, the number of bridging oxygen around silicon increased with the increase in the PO2.5 concentration.