Method for preparing white carbon black with polyaluminum ferric sulfate as byproduct from fly ash

The invention provides a method for preparing white carbon black with polyaluminum ferric sulfate as a byproduct from fly ash, and belongs to the field of chemical engineering. Microwave decomposition of the fly ash is carried out to extract silicon for preparing white carbon black and extract ferro-aluminum for preparing polyaluminum ferric sulfate. Unique properties of microwaves are used and directly act on substance molecules to realize mutual friction between the molecules and generate a large amount of heat, so the implementation of the reaction is promoted, so the reaction time of the microwave reaction mode is greatly shortened to 1/6 of original reaction time, a steam boiler, a heat conduction oil furnace and other heating devices are saved, and the cost and the energy consumption are reduced; and a material obtained after the microwave reaction is easy to separate, so the requirements of a separation device are reduced, the recovery rate of valuable elements in the fly ash reaches above 98%, and the high efficiency and low energy comprehensive utilization effects of the fly ash are truly reached.