Abstract:A new process to extract alumina from high alumina fly ash by pre-desilication sintering process was proposed to solve the technical problem of comprehensive utilization of high alumina fly ash. The new process cancelled carbonation decomposition of sodium aluminate solution and applied whole seed decomposition process. By optimizing the synthesis technology and using high caustic ratio synthesis technology, 4A zeolite for washing can be produced from spent liquor and sodium silicate solution. In production process, by supplementing a small amount of sodium silicate for adjusting output of aluminum hydroxide and 4A zeolite, material balance of production system can be better guaranteed. The new process eliminated lime furnace, alumina baking furnace, sodium aluminate solution carbonation decomposition and deep desilication process, which reduces energy consumption, waste residue emission and carbon emission. The production process of this technology is relatively simple, technical feasibility, good economy and has strong competitiveness.