Analysis on Reductive Kinetics of SSI Reduced by Hydrogen

Abstract:

Spherical sponge iron (SSI) with high activity and intension could be prepared through direct reduction by hydrogen. To optimize the reduction technology, reductive kinetics of SSI was analyzed on the basement of unreacted core model. In the light of the single reaction surface theory, the ratio of internal diffusion resistance fI and chemical reaction resistance fR was calculated according to the weight loss curve of SSI reduction. Under different temperature, both fI and fR increased with the reaction time, especially the radium of unreacted core was small after a period of reaction time. Compared the ratio of fI and fR, it concluded that SSI reduced by hydrogen was controlled by the chemical reaction, combination of chemical reaction and the internal diffusion, the internal diffusion under the temperature being lower than T3, from T3 to T4, more than T5, respectively.

• Periodical: Advanced Materials Research (Volumes 450-451)
• Pages: 174-178
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.450-451.174
• Online since: January 2012
• Authors: Jun Guo Li, Shou Zhang Li, Wei Tian
• Keywords: Chemical Reaction Resistance, Internal Diffusion Resistance, Reduction Temperature, Spherical Sponge Iron (SSI), Unreacted Core Model

References

[1] M. Kumar, S. Chakraborty, Chemical denitrification of water by zero-valent magnesium powder. J Hazard. Mater., B135(2006), p.112.

[2] G. C. C. Yang, H. L. Lee, Chemical reduction of nitrate by nanosized iron: kinetics and pathways. Water Res., 39(2005), p.884.

DOI: 10.1016/j.watres.2004.11.030

[3] Y. P. Feng, J. G. Li, N. Bi, X. L. Yan, Static experimental research on nitrate reduction removal from water by spherical sponge iron. Environ. Sci. and Technol., 6(2008), p.14.

[4] S. Choe, H. M. Liljestrand, J. Khim, Nitrate reduction by zero-valent iron under different pH regimes. Applied Geochem., 19(2004), p.335.

DOI: 10.1016/j.apgeochem.2003.08.001

[5] A. Yazdankhah, S. E. Moradi, S. Amirmahmoodi, M. Abbasian, S. E. Shoja, Enhanced sorption of cadmium ion on highly ordered nanoporous carbon by using different surfactant modification. Microporous and Mesoporous Mater., 1(2010), p.35.

DOI: 10.1016/j.micromeso.2010.04.012

[6] S. M. Ponder, J. G. Darab, T. E. Mallouk, Remediation of Cr(VI) and Pb(II) aqueous solutions using supported, nanoscale zero-valent iron. Environ. Sci. Technol., 12 (2000) 2564-2569.

DOI: 10.1021/es9911420

[7] J. G. Li, J. Li, Y. G. Li, Cadmium removal from wastewater by sponge iron sphere prepared by charcoal direct reduction. J. Environ. Sci. suppl (2009), p.60.

DOI: 10.1016/s1001-0742(09)60038-3

[8] J. G. Li, L. H. Wei, Y. G. Li, N. Bi, F. F. Song, Cadmium removal from wastewater by sponge iron sphere prepared by hydrogen reduction. J. Environ. Sci. suppl.(2011), p.114.

DOI: 10.1016/s1001-0742(11)61090-5

[9] Y. R. Wang, J. G. Li, G. J. Zhao, L. X. Xu, Y. T. Li, In situ observations of microstructural and morphological changes of the reduction product of magnetite in H2/Ar gas mixtures. Acta Metall. Sinica. 6 (1998), p.571.