System and method for producing high-purity aluminum oxide by recycling fly ash

The invention relates to a system and a method for producing high-purity aluminum oxide by recycling fly ash. The system comprises a grinding machine, a pre-desiliconization reactor, an activation calcination reactor, an acid leaching reactor, a ferric hydroxide purification reactor, a neutralization reactor and a high-temperature calcination reactor which are sequentially connected along the aluminum oxide extraction direction, wherein the pre-desiliconization reactor is further connected with a pre-desiliconization agent doser, the activation calcination reactor is further connected with an activating agent doser, the acid leaching reactor is further connected with an acid leaching liquid doser, the ferric hydroxide purification reactor is further connected with a ferric hydroxide purifying agent doser, and the neutralization reactor is further connected with a neutralizer doser. Compared with the prior art, the system and method have the advantages that the comprehensive utilization of the fly ash is reali