The iron ore tailings were mixed with NaOH-NaNO3 and calcined at 500℃ for 3 h to produce soluble sodium silicate.The iron ore tailings and NaOH were used as raw materials

and NaNO3 was used as molten salt.The precipitated silica particle was prepared by using sodium silicate as a source of silicon by the chemical precipitation method.The composition

morphology and structure of the synthesized particles were characterized by X-ray diffraction (XRD)

FTIR analysis

transmission electron microscopy (TEM) analysis

and X-ray fluorescence analysis (XRF).The SiO2 purity in the precipitated silica product was 99.3% by XRF.The chemical structure of precipitated silica was hydrated silicon oxide by FTIR analysis.The structure of precipitated silica was amorphous by XRD analysis.The TEM micrograph showed that the shape of precipitated silica particles was nearly spherical

and the average grain diameter was about 100 nm.The specific surface area was 152 m2 8226;g-1 by the BET method.