Abstract:Oil shale residue as a raw material of producing precipitated silica was firstly calcined for 4 h at 950℃ and treated by NaOH solution with 3.30 mol/L for 4 h, and then acidified by HCl until the pH value of solution was up to 8~9, the leaching rate of SiO2 in the residue reached 75.8%. The SiO2 purity in the precipitated silica product was 91.8% by X-ray fluorescence analysis. The chemical structure of precipitated silica was hydrated silicon oxide through FT-IR 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 less than 50 nm. The specific surface area of precipitated silica was 114 m2/g, pH was 5.5~6.0, heating loss was 5.82%, loss on ignition at 1000℃ was 6.16%. The product could be comparable with the requirements of HG/T 3061-1999 industrial product standard.