Synthesis of magadiite using a natural diatomite material

BACKGROUND: This study investigated the synthesis of magadiite from a natural diatomite material. The influence of key reaction parameters, including reaction time, temperature and molar ratios of Na 2 O/SiO 2 and H 2 O/Na 2 O, on the formation of magadiite were investigated. The as‐synthesized magadiite was characterized by X‐ray powder diffraction, scanning electron microscopy, infrared spectroscopy, thermogravimetry and differential thermal analysis. RESULTS: The well crystallized magadiite with a rosette like morphology was prepared from a dispersion with the molar ratio H 2 O/Na 2 O = 28.15 and Na 2 O/SiO 2 = 0.15 by heating at 160 °C for 42 h. The basal space of the synthesized magadiite is 15.5 Å and the stretching and bending frequencies of the SiO 4 units making up the magadiite layer were recorded. The layered structure was destroyed when the temperature rose above 250 °C, and combining the results of thermogravimetry and differential thermal analysis suggested the structural alteration may be due to the condensation of silanol groups. CONCLUSION: Diatomite has been used to synthesize magadiite with a high purity and well crystallized. The cost of synthesis has been reduced allowing its use in conventional industrial applications, thus expanding the commercial utilization of diatomite. Copyright © 2009 Society of Chemical Industry