The invention belongs to a resourceful, economic and fine utilization method of
coal ash, and relates to a method for producing superfine white
carbon black,
ferric hydroxide and aluminum
oxide by using
coal ash. The method comprises the following steps of: with the
coal ash as a
raw material and a
sulfuric acid and caustic soda solution as a
solvent,
grinding the coal ash, heating to assist in dissolving the coal ash, carrying out acid leaching on the coal ash, and then, filtering and cleaning the coal ash to obtain a filtrate, wherein the filtrate is used for preparing the
ferric hydroxide and the aluminum
oxide, a
filter cake obtained through leaching and filtering is used for preparing the superfine white
carbon black, and a
fluoride-contained gas generated through leaching is used for absorbing and preparing an AlF3 product. By using the method, the problem that the industrial application can not be realized because the traditional coal ash leaching way is low in useful substance
leaching rate is better solved fundamentally, and the total useful substance
dissolution rate of the coal ash can be increased from 15-20% to 75-85%, so that resourceful utilization, economic and fine utilization, product diversification and higher additional value of the coal ash can be realized.