Synthesis of Hydroxysodalite From Paper Sludge Ash Using NaOH-LiOH Mixtures

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Takaaki Wajima, (2017). Synthesis of Hydroxysodalite From Paper Sludge Ash Using NaOH-LiOH Mixtures. Mechanics, Materials Science & Engineering, Vol 9. doi:10.2412/mmse.40.5.622

Authors: Takaaki Wajima

ABSTRACT. Hydroxysodalite zeolite was synthesized at 90 oC from paper sludge ash, which is industrial wastes in paper manufacturing, using NaOH-LiOH mixed solution. Paper sludge ash was discharged from paper making plant as industrial wastes, and the amount is increasing annually. The new utilization of paper sludge ash is desired. Hydroxysodalite can be used to remove HCl gas at high temperature, and there are papers for hydroxysodalite synthesis from various ashes, for example, coal fly ash. In my previous study, hydroxysodalite can be synthesized from paper sludge ash. However, little information can be available on the synthesis of hydroxysodalite from paper sludge ash. Therefore, we attempted to examine the synthesis of hydroxysodalite from paper sludge ash using NaOH-LiOH mixtures. Hydroxysodalite [Na6Al6Si6O24‧8H2O] was obtained in the mixed solution with Li / (Li + Na) ratios smaller than 0.25, while katoite [Ca3Al2(SiO4)(OH)8] was formed in the mixed solutions with the other molar ratios, due to the dissolution of gehlenite [Ca2Al2SiO7]. The observed concentrations of Si and Al in the solution during the reaction explain the synthesis of reaction products, which depends on alkali species.

Keywords: Hydroxysodalite, Katoite, Gehlenite, Paper sludge ash, NaOH-LiOH mixture, Synthesis reaction

DOI 10.2412/mmse.40.5.622


[1] R.M. Barrer, Zeolites and Clay Minerals as Sorbents and Molecular Sieves, Academic Press, 1978.

[2] M. Singh, M. Garg, Cementitious binder from fly ash and other industrial wastes, Cem. Concr. Res., Vol. 29, 1999, 309-314. DOI: 10.2138/am.2007.2251

[3] R. Kikuhi, Recycling of municipal solid waste into cement clinker, Resour. Conserv. Recycl., Vol. 31, 2001, 137-147. DOI: 10.1016/S0921-3449(00)00077-X 

[4] T. Wajima, H. Ishimoto, K. Kuzawa, K. Ito, O. Tamada, M.E. Gunter, J.F. Rakovan, Material conversion from paper-sludge ash in NaOH, KOH, and LiOH solutions, Am. Mineral., Vol. 92, 2007, 1105-1111. DOI: 10.2138/am.2007.2251

[5] T. Wajima, Kinetics of the removal of hydrogen chloride gas using hydroxysodalite at high temperatures, Int. J. Chem. Eng. Appl., Vol. 7, 2016, 235-238. DOI: 10.18178/ijcea.2016.7.4.580

[6] J. Kragten, Atlas of Metal-ligand Equilibria in Aqueous Solution, Ellis Horwood Limited, 1978.

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