Abstract: The demineralization of waste coke was investigated by using different leaching agents and an alkali-acid leaching process was determined as final.The relation between leaching temperature and the degree of demineralization was studied.The contents and phases of Fe, Al, Ca, and Si in the coke power ash were analyzed by the methods of spectroscopy, X-ray diffraction and chemical analysis.According to XRD characterization of raw material and product, the reactions occurred in the processes of alkali leaching and acid leaching were discussed.After the leaching, the ash reduced from 28.6% to 3.85%, and the demineralization rate was up to 86.5%.