Abstract: White carbon black is the general term of all the white powdered amorphous silica and silicates， which can be used widely in multiple fields.The acid-leached residue of coal gangue getting from the aluminum extraction process contains 80%~90% SiO2（mass fraction），which is a main raw material of white carbon black.In this study，acid-leached residue reacted with sodium carbonate in the molten state at 750~850 ℃，then sodium silicate solution was obtained under high water pressure at 200 ℃.White carbon black was finally prepared through carbonization process.The optimized process conditions were obtained be as follows: sodium/silicate ratio was 1.5（amount-of-substance ratio of Na2O to SiO2），mass concentration of sodium silicate was 1.07 g/cm3，additives of ethanol concentration was 4 mol/L，PEG concentration was 1.11×10-5 mol/L， and CTAB concentration was 9×10-4 mol/L.Results showed the white carbon black performed best prepared under the optimal conditions.

Key words: coal gangue, acid-leached residue, sodium silicate, carbonization, white carbon black