Physical and Adsorptive Characterization of Precipitated Magnesium Silicate from Rice Hull Ash Silica

SAYAN P., Titiz-Sargut S., Ozgul-Yucel S., Kiran B.

CHEMICAL ENGINEERING & TECHNOLOGY, vol.34, no.9, pp.1497-1506, 2011 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 34 Issue: 9
  • Publication Date: 2011
  • Doi Number: 10.1002/ceat.201000478
  • Journal Name: CHEMICAL ENGINEERING & TECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1497-1506
  • Yıldız Technical University Affiliated: Yes

Abstract

Precipitation of magnesium silicate from sodium silicate and MgCl2 and MgSO4 solutions was investigated at four different reactant feed rates and two temperatures (25 degrees C and 50 degrees C). Sodium silicate solutions were produced from rice hull ash silica. The final product was characterized by scanning electron microscopy, X-ray diffraction, thermogravimetric analysis/differential thermal analysis, crystal size distribution, and filtration rate measurements. Physical characteristics of the studied magnesium silicates were determined by the Brauner-Emmett-Teller method and their adsorption capacities were compared to commercial magnesium silicate (Florisil). The adsorption was spontaneous and endothermic. The best fit of the kinetic results was achieved by a pseudo-second-order equation. The equilibrium data were found to be well represented by the Freundlich isotherm equation.