XRD and Morphologic Analysis of α-Cristobalite Produced from Silica Mine Waste under Lower Calcination Temperature

Abstract:

This paper describes a new method developed to produce α-cristobalite from silica mine waste under lower-than-usual temperature, and presents XRD (X-ray diffraction) and morphologic analysis of the produced α-cristobalite. In the method, silica mine waste with average grain volume of 87.3 µm is firstly refined and processed to have a whiteness of 83.5 and a chemical composition of SiO₂ of 99.87%, Al₂O₃ of 0.15%, and Fe₂O₃ of 0.015% (by weight), before calcinating the processed samples. The experiment results demonstrate that, under oxidizing condition, addition of mineralizer and occurrence of iron oxides as impurity in the mine waste, facilitate lowering both crystallization temperature of amorphous silica and calcination temperature of cristobalite from 1470°C to 1100-1250°C, shortening formation time of cristobalite to 3 hours, raising transformation rate up to 93.7%-99.7%, and increasing whiteness up to 92.3%-96.7%.

• Periodical: Materials Science Forum (Volume 686)
• Pages: 692-695
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.686.692
• Online since: June 2011
• Authors: Nan Chun Chen, Wen Hui Wu, Zhao Li, Ai Ping Deng
• Keywords: Morpholoy, Silica Mine Waste, Transformation Rates, X-Ray Diffraction (XRD), α-Cristobalite

References

[1] K.Y. He, Silicate Physical-Chemistry[M] (1997), p.76.

[2] T.C. Chen, S.M. Zhou and G. Yang, Non-metallic Mines (2005)Vol. 28(5), p.37~38.

[3] H.R. Wen, Y. Zhang and J.X. Wang, Jiansu Chemical Industry(1993) Vol. 21(3), p.17~18.

[4] G.L. Yu, N. Li and J.L. Xu, Journal of Wuhan Yejin University of Science and Technology (2005)Vol. 28(3), p.225~227.

[5] M.Y. Chen and Z.D. Li, Foundry (1993), p.9~13.

[6] W.S. Xiao, J.Y. Chen. Journal of Mineralogy and Petrology (2003)Vol. 23(4), p.5~10.

[7] J.S. Wang, J. Wang and W.C. Li, China Ceramics (1992) (6), p.1~4.

[8] W.L. Guo, Nation Defence Industry Press (1982), p.73~74.