Thermal oxidation of SiAlON powders synthesized from coal gangue

Abstract

The oxidation behavior of different SiAlON phases (β-SiAlON, X-phase SiAlON and 12H powders) synthesized from coal gangue in air atmosphere was investigated using isothermal thermogravimetry (TG) and field-emission scanning electron microscopy (FE-SEM). The effect of ferric oxide impurities in coal gangue was studied. The results show that ferric oxide contributes to the growth of SiAlON crystalline during the synthesis process. In the oxidation experiment, the existence of ferric oxide decreases the oxidation resistance of SiAlON. The reason is that the impurity causes the formation of a liquid phase at a higher temperature. At 1423–1623 K, the oxidation of SiAlON powders is diffusion controlled and it can be described by Chou’s model. A fair agreement is found between theoretical calculations and the experimental data.

Keywords

oxidation / kinetics / silicon compounds / powders / coal

References

[1] Oyama Y., Kamigaito K. Solid solubility of some oxides in Si₃N₄. Jpn. J. Appl. Phys., 1971, 10, 1637.

[2] Jack K.H. Solid solubility of alumina in silicon nitride. Trans. J. Br. Ceram. Soc., 1973, 72, 376.

[3] Jack K.H., Wilson W.I. Ceramics based on the Si-Al-O-N and related systems. Nat. Phys. Sci., 1972, 238, 28.

[4] Mazzoni A.D., Aglietti E.F. Mechanism of the carbonitriding reactions of SiO₂-Al₂O₃ minerals in the Si-Al-O-N system. Appl. Clay Sci., 1998, 12, 447.

[5] Li F.J., Wakihara T., Tatami J., et al. Elucidation of the formation mechanism of β-SiAlON from a zeolite. J. Am. Ceram. Soc., 2007, 90, 1541.

[6] Wang J., Li N., Shi C.C., et al. β-SiAlON produced by carbon thermal nitriding reaction of bauxite. J. Univ. Sci. Technol. Beijing, 2000, 7(3): 209.

[7] Wang X.D., Bao H., Li W.C. Oxidation of O′-SiAlON-ZrO₂ composite ceramics. J. Univ. Sci. Technol. Beijing, 2001, 8(1): 43.

[8] Nordberg L.O., Nygren M., Käll P.O., et al. Stability and oxidation properties of RE-α-Sialon ceramics (RE=Y, Nd, Sm,Yb). J. Am. Ceram. Soc., 1998, 81, 1461.

[9] Ramesh R., Byrne P., Hampshire S., et al. Kinetics of weight changes and morphological developments during oxidation of pressureless sintered β-SIALONS. J. Eur. Ceram. Soc., 1997, 17, 1901.

[10] Lewis M.H., Barnard P. Oxidation mechanisms in Si-Al-O-N ceramics. J. Mater. Sci., 1980, 15, 443.

[11] Ramesh R., Byrne P., Pomeroy M.J. Oxidation studies of a high Al substituted β-Sialon. J. Mater. Process. Technol., 1996, 56, 600.

[12] MacKenzie K.J.D., Shimada S.S., Aoki T. Thermal oxidation of carbothermal β′-sialon powder: Reaction sequence and kinetics. J. Mater. Chem., 1997, 7, 527.

[13] MacKenzie K.J.D., Sheppard C.M., Barris G.C., et al. Kinetics and mechanism of thermal oxidation of sialon ceramic powders. Thermochim. Acta, 1998, 318, 91.

[14] Chou K.C. A kinetics model for oxidation of Si-Al-O-N materials. J. Am. Ceram. Soc., 2006, 89, 1568.

[15] Chou K.C., Hou X.M. Kinetics of high temperature oxidation of inorganic non-metallic materials. J. Am. Ceram. Soc., 2009, 92, 585.

[16] Hou X.M., Chou K.C., Hu X.J., et al. A new measurement and treatment for kinetics of isothermal oxidation of Si₃N₄. J. Alloys. Compd., 2008, 459, 123.

[17] Hou X.M., Chou K.C., Zhong X.C., Seetharaman S. Oxidation kinetics of aluminum nitride at different oxidizing atmosphere. J. Alloys Compd., 2008, 465, 90.

[18] Hou X.M., Zhang G.H., Chou K.C. A comparison of oxidation kinetics of O′-SiAlON and β-SiAlON powders synthesized from bauxite. Int. J. Appl. Ceram. Technol., 2008, 5, 529.

[19] Ge T.Z., Liang Y.H., Zhong X.C. Preparation, property and microstructure of bauxite-based fused corundum-zirconia and mullite-zirconia materials. Refractories, 2005, 39, 101.

[20] Li S.P. Effect of Impurities of Fe₂O₃ and TiO₂ on SiAlON Synthesis from Bauxite, 2004 Zhengzhou, Zhengzhou University, 53.

[21] Jander W. Reactions in solid states at room temperature I: Announcement the rate of reaction in endothermic conversions. Z. Anorg. U. Allgem. Chem., 1927, 163, 1.

[22] Hou X.M., Chou K.C. Comparison of the diffusion control models for isothermal oxidation of SiAlON powders. J. Am. Ceram. Soc., 2008, 91, 3315.