PREPARATION OF ALUMINA FROM RETORTING RESIDUE OF OIL SHALE

In this research, the leaching and preparation of [Al.sub.2][O.sub.3] from retorting residue of Fushun east open-pit oil shale in China were investigated. The optimum acid leaching conditions are the following: activation temperature is 850 °C, activation time is 1h, the particle size of the raw material is 0.074 mm, the concentration of acid is 12%, the liquid to solid ratio is 5:1, reaction temperature is 100 °C and reaction period is 1.5 h. The homogeneous chemical precipitation method was applied for the preparation of alumina. Optimum conditions for alumina preparation were determined and are as follows: reaction at 55 °C for 1.5 h, the concentration of sodium meta aluminate is 0.4 mol/L, the dose of surfactant is 0.3%. The product can be effectively purified by washing with 25% acetic acid, and then characterized by laser particle size distribution, X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results prove that the product is γ-[Al.sub.2][O.sub.3] with particle diameters in the range of 0.6-0.9 µm, and its degree of purity is 98.7%.