Preparation of amorphous silica from coal-based kaolin

A novel preparation method for amorphous silica from coal-based kaolin was developed. The properties of the sample were extensively investigated by changing the addition amount and concentration of acid, reaction time, calcination temperature and so on. The surface area and pore distribution, phase structure, morphology, particle size distribution, the amount of Si and Al of samples were respectively characterized by methods of N\-2-adsorption, X-ray diffraction, scan electron microscope and laser particle analyzer. The results show that the surface area of amorphous silica is far larger than that of traditional method. The amorphous silica bears the developed mid pore structure, villiform pattern and uniform particle size. The quality of amorphous silica obtained by novel method is superior to the state quality standard.