Effect of Na2O on the sintering and melting behavior of CaO-SiO2-CaF2 slag

Funian Han; Liang Yu; Guanghua Wen; Jun Guo; Chunhua Ran; Shaopeng Gu

Journal of Materials Research and Technology (Jul 2022)

Effect of Na2O on the sintering and melting behavior of CaO-SiO2-CaF2 slag

Funian Han,
Liang Yu,
Guanghua Wen,
Jun Guo,
Chunhua Ran,
Shaopeng Gu

Affiliations

Funian Han: College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, China; Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials, Chongqing University, Chongqing, 400044, China
Liang Yu: College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, China; Electron Microscopy Center of Chongqing University, Chongqing University, Chongqing, 400044, China; Corresponding author.
Guanghua Wen: College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, China; Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials, Chongqing University, Chongqing, 400044, China
Jun Guo: College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, China; Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials, Chongqing University, Chongqing, 400044, China
Chunhua Ran: College of Materials Science and Engineering, Chongqing University, Chongqing, 400044, China; Electron Microscopy Center of Chongqing University, Chongqing University, Chongqing, 400044, China
Shaopeng Gu: College of Metallurgy and Energy, North China University of Science and Technology, Tangshan, 063210, China; Corresponding author.

Journal volume & issue: Vol. 19
pp. 866 – 876

Abstract

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In this study, the effect of Na2O on the sintering and melting behavior of representative CaO-SiO2-CaF2 slag were synthetically investigated by TG-DSC, DIL, XRD, SEM, XPS, and BET. As expected, most shrinkage of CaO-SiO2-CaF2 slags with and without Na2O during the sintering process originated from solid-phase sintering, and the formation temperature of cuspidine as the sintering phase was reduced by Na2O to 550 °C. While Na2O also transformed Ca4Si2O7F2 to Ca2NaSiO4F at 650 °C–880 °C and caused unexpected volume expansion, owing to increased cell volume and corresponding pore expansion. Moreover, Na2O reduced the melting point of CaO-SiO2-CaF2 slag and promoted the volatilization of fluoride by changing the final phase before melting.

Published in Journal of Materials Research and Technology

ISSN: 2238-7854 (Print); 2214-0697 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.journals.elsevier.com/journal-of-materials-research-and-technology/

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