Microstructural Study and Thermal Behavior of Sodium Silicofluoride

Year 2020, Volume: 12 Issue: 1, 113 - 117, 31.01.2020

Aslı Çakır Arianpour , Farzin Arianpour , Behnam Ali

https://doi.org/10.29137/umagd.572978

Abstract

Sodium
silicofluoride, with the chemical formula of Na₂SiF₆, is
an inorganic synthetic material which recently found lots of applications in
various industries such as ceramic, metallurgy and chemical engineering. One of
the main important usages of this powder is in the production of opal
glass-ceramics, glazes and frits. Despite the expansion of its applications,
the properties of this material were not investigated deeply elsewhere. In this
research, a commercial sodium silicofluoride powder was studied and
characterized in terms of thermal behavior and microstructure. The thermal
analysis was investigated according to the differential thermal and thermo
gravimetry curves by heating the material up to 900 °C in air. The microstructural
analyses were also performed using scanning and transmission electron
microscopies to study the grain size and morphology of the particles. The
results showed that this commercial sodium silicofluoride material is
decomposed in the temperature range of 430-600 °C in air by an accompanied endothermic
reaction. The microstructural characterizations were also clarified the granular
morphology of the studied SSF powder, existence of the hexagonal shaped prisms and
associated pores.

Keywords

Sodium silicoflouride, Characterization, Thermal analysis, , Electron microscopy

Supporting Institution

KASTAMONU ÜNİVERSİTESİ

Project Number

KU-BAP01/2018-46

Thanks

The authors would like to thank Research and Application Center (MERLAB, Kastamonu University, Kastamonu, Turkey) for experimental tests. This research was granted by KU-BAP01/2018-46 project of Kastamonu University, Kastamonu, Turkey.

Sodyum Silikoflorürün Mikroyapı ve Isıl Davranışlarının İncelenmesi

Abstract

Sodyum
silikoflorür, Na₂SiF₆'nın kimyasal formülü ile son
zamanlarda seramik, metalurji ve kimya mühendisliği gibi çeşitli endüstrilerde
birçok uygulama alanı bulan inorganik sentetik bir malzemedir. Bu tozun en
önemli kullanımlarından bazıları opal cam-seramik, sırlar ve fritlerdir.
Uygulama alanlarının gün geçtikçe artmasına karşı, literatürde sodium
silikoflorür (SSF) ile ilgili sınırlı sayıda kaynak mevcuttur. Bu araştırmada,
ticari bir sodyum silikoflorür tozunun ısıl davranış ve mikroyapı açısından
karakterize edilmiştir. Termal analiz, hava atmosferinde 900 °C’de diferansiyel
termal ve termo gravimetri eğrilerine göre araştırılmıştır. Mikroyapısal
analizler, taneciklerin tane büyüklüğü ve morfolojisini incelemek için taramalı
ve geçirimli elektron mikroskopları kullanılarak yapılmıştır. Sonuçlar, ticari
sodyum silikoflorür malzemesinin, eşlik eden bir endotermik reaksiyonla havada
430-600 °C sıcaklık aralığında çözündüğünü göstermiştir. Mikroyapısal
karakterizasyonlarla, incelenen SSF tozunun granüler morfolojisi, altıgen
şekilli prizmaların ve ilgili gözeneklerin varlığına da açıklık getirmiştir.

Keywords

Sodyum silicoflorür, Karakterizasyon, Termal analiz, Elektron mikroskobu

Project Number

KU-BAP01/2018-46

References

• Andreeva, V. & Fekeldjiev, G. (1986) Use of nonconventional raw materials in ceramic production. Ceramics International, 12, 229-235.
• Arai, T. & Adachi, S. (2011) Mn-activated Na2SiF6 red and yellowish-green phosphors: A comparative study. Journal of Applied Physics, 110, 063514.
• Ciavatta, L., Iijliano, M. & Porto, R. (1988) Fluorosilicate equilibria in acid solution, Polyhedron, 7 (18), 1773-1779.
• Coyle, G. J., Tsang, T. & Adler, I. (1981) XPS studies of surface damages of transition metal fluorosilicates under argon ion bombardment. Surface Science, 112, 197-205.
• Hattab, F. N. (1987) Direct determination of fluoride in selected dental materials. Dent. Mater., 3, 67-70.
• Jeong, H. L. & Huh, Y.D. (2010) Synthesis of hexagonal prisms and hexagonal plates of Na2SiF6 microcrystals. Materials Letters, 64, 1816-1818.
• Khan, M. S., Shahzadi, P., Alam, S., Javed, K., Shaheen, F., Naqvi, J. & Shahnaz, A. (2015) Development of heat resistant borosilicate glass doped with sodium silico fluoride compound. Journal of Chemistry and Materials Research, 4, 1, 13-18.
• Kumar, M., Nani Babu, M., Mankhand, T.R. & Pandey, B.D. (2010) Precipitation of sodium silicofluoride (Na2SiF6) and cryolite (Na3AlF6) from HF/HCl leach liquors of alumino-silicates, Hydrometallurgy, 104, 304-307.
• Smith, G. E. (1985) Toxicity of fluoride-containing dental preparations: A review. The Science of the Total Environment, 43, 41-61.
• Toure, A. O., Keinde, D., Sambe, F. M., Joseph, M. & Diop C. G. M. (2017) Use of a fluoride waste in the raw mix for clinker manufacturing. American-Eurasian Journal of Scientific Research, 12, 1, 1-6.
• Vanka, M. & Vachuska, J. (1980) Thermal decomposition of sodium hexafluorosilicate. Thermochimica Acta, 36, 387-391.
• Yeo, B. E., Cho, Y. S.& Huh, Y. D. (2016) Synthesis and photoluminescence properties of a red-emitting phosphor K2SiF6:Mn4+ for use in three-band white LED applications, Optical Materials, 51, 50-55.