Kinetics Analysis on Mixing Calcination Process of Fly Ash and Ammonium Sulfate

doi:10.1016/j.cjche.2014.06.033

Abstract

Abstract: The further development of the extraction of alumina that is produced in the calcination process of ammonium sulfate mixed with fly ash was limited because of the lack of systematic theoretical study. In order to aggrandize the research of the calcination process, the kinetics and reaction mechanism of the calcinationswere studied. The result suggests that there are two stages in the calcination process, and the alumina extraction rate increases swiftly in the initial stage, but slows down increasing in the later stage. The apparent activation energy of the initial and later stages equals to 13.31 and 35.65 kJ·mol^-1, respectively. In the initial stage, ammonium sulfate reacts directly with mullite in the fly ash to form ammonium aluminum sulfate, while in the later stage, aluminum sulfate is formed by the reaction between ammonium aluminum sulfate and ammonium sulfate.

Key words: Mixing calcinations, Kinetics, Activation energy, Reaction mechanism

摘要： The further development of the extraction of alumina that is produced in the calcination process of ammonium sulfate mixed with fly ash was limited because of the lack of systematic theoretical study. In order to aggrandize the research of the calcination process, the kinetics and reaction mechanism of the calcinationswere studied. The result suggests that there are two stages in the calcination process, and the alumina extraction rate increases swiftly in the initial stage, but slows down increasing in the later stage. The apparent activation energy of the initial and later stages equals to 13.31 and 35.65 kJ·mol^-1, respectively. In the initial stage, ammonium sulfate reacts directly with mullite in the fly ash to form ammonium aluminum sulfate, while in the later stage, aluminum sulfate is formed by the reaction between ammonium aluminum sulfate and ammonium sulfate.

关键词: Mixing calcinations, Kinetics, Activation energy, Reaction mechanism

Peng Wang, Laishi Li, DezhouWei. Kinetics Analysis on Mixing Calcination Process of Fly Ash and Ammonium Sulfate[J]. , 2014, 22(9): 1027-1032.

References

[1] J.D.Wang, Y.C. Zhai, X.Y. Shen, Alumina extraction from de-silicate fly ash with lime sintering process, Light Met. 6 (2009) 14-16.
[2] L.S. Li, Y.Y. Liu, Y.C. Zhai, Y.Wu, J.D.Wang, Alumina extraction from fly ash by sulfuric acid calcinations, J. North. Univ. 30 (S2) (2009) 169-172.
[3] K. Gborphlip, S.J. Hooque, Q. Charles, Dissolution behavior of Fe, Co, and Ni from non-ferrous smelter slag in aqueous sulphurdioxide, Hydrometallurgy 81 (2006) 130-141.
[4] G.H. Bai, Y.H. Qiao, B. Shen, S.L. Chen, Thermal decomposition of coal fly ash by concentrated sulfuric acid and alumina extraction process based on it, Fuel Process. Technol. 92 (2011) 1213-1219.
[5] H. Liu, V.G. Papanglak, Thermodynamic equilibrium of the O2-ZnSO4-H₂SO4-H₂O system from 25 to 250℃, Fluid Phase Equilib. 234 (2005) 122-130.
[6] R.L. Fang, S. Lu, X.B. Xie, The study of high-purity super-fine alumina powder preparation with fly ash, Environ. Eng. 5 (2003) 40-42.
[7] H. Zhao, S. Lu, The study of high-purity super-fine alumina powder preparation with fly ash, Compr. Util. Fly Ash 6 (2002) 8-10.
[8] S. Lu, R.L. Fang, H. Zhao, The study of high-purity super-fine alumina powder recovered from fly ash by lime sintering self-powder method, Fly Ash 1 (2003) 15-17.
[9] Y.R. Ren, Z.K. Zhu, D.L. Xu, P.X. Fu, The study of high-purity alumina preparation by thermal decomposition of aluminum ammonium sulfate, Inorg. Chem. Ind. 6 (1991) 21-25.
[10] C. Chen, L.B. Evans, A local composition model for the excess Gibbs energy of aqueous electrolyte systems, AIChE J. 32 (1986) 444-454.
[11] H.C. Park, Y.J. Park, R. Stevens, Synthesis of alumina from purity alum derived from coal fly ash, Mater. Sci. Eng. 367 (2004) 166-170.
[12] L.S. Li, Y.C. Zhai, J.G. Qin, Y.Wu, Y.Y. Liu, Extracting high-purity alumina from fly ash, J. Chem. Ind. Eng. 57 (9) (2006) 2189-2193 (in Chinese).
[13] X.L. Jin, T. j Peng, H.J. Sun, Mineral composition and variation rule of calcinations products of ammonia sulfate and fly ash, Acta Mieralogica Sinica 33 (2) (2013) 147-151.
[14] C.S. Fu, Non-ferrous Metal Principle, Metallurgical Industry Press, Beijing, 1993.
[15] K. Sun, Macro reaction Kinetics and Its Analytic Method, Metallurgical Industry Press, Beijing, 1998.
[16] A.M. Ginstling, B.I. Brounshtein, Diffusion kinetics of reaction in spherical particles, Russ. J. Appl. Chem. 23 (12) (1950) 1327-1338.
[17] D.S. Abrams, J.M. Prausnitz, Statistical thermodynamics of liquid mixtures: A new expression for the excess Gibbs energy of partly or completely miscible systems, AIChE J. 21 (1975) 116-128.
[18] H.G. Li, The Principle of Metallurgy, Science Press, Beijing, 2005.
[19] Z.Y. Zhang, J.H. Peng, Z.B. Zhang, Leaching zinc fromspent catalyst: Process optimization using response surface methodology, J. Hazard. Mater. 176 (2010) 1113-1117.
[20] A. Haghtalab, V.G. Papanglakis, X. Zhu, The electrolyte NRTL model and speciation approach as applied to multicomponent aqueous solutions of H₂SO4, Fe2(SO4)3, MgSO4 and Al2(SO4)3 at 230-270℃, Fluid Phase Equilib. 220 (2004) 199-209.
[21] K. Thomsen, P. Rasmussen, R. Gani, Correlation and prediction of thermal properties and phase behavior for a class of aqueous electrolyte systems, Chem. Eng. Sci. 51 (1996) 3675-3683.
[22] S.J.Wu, X. Yu, Z.H.Hu, L.L. Zhang, Optimizing aerobic biodegradationof dichloromethane using response surface methodology, J. Environ. Sci. 21 (9) (2009) 1276-1283.
[23] H. Liu, V.G. Papangelakis, Chemical modeling of high temperature aqueous processes, Hydrometallurgy 79 (2005) 48-61.
[24] K. Ravikumar, K. Pakshirajan, T. Swaminathan, K. Balu, Optimization of batch process parameters using response surface methodology for dye removal by a novel adsorbent, Chem. Eng. 105 (2005) 131-138.
[25] L.S. Li, Y.Y. Liu, Thermodynamics of extracting alumina from fly ash by ammonium sulfate calcinations process, Light Met. 9 (2009) 12-14.