Abstract: Provided a method for preparing metallurgical-grade alumina by using fluidized-bed fly ash, comprising: a) removing iron by wet magnetic separation after crushing the fly ash; b) reacting the fly ash after magnetic separation with hydrochloric acid to obtain a hydrochloric leachate; c) passing the hydrochloric leachate through macro-porous cationic resin to deeply remove iron to obtain a refined aluminum chloride solution; d) concentrating and crystallizing the refined aluminum chloride solution to obtain an aluminum chloride crystal; and e) calcining the aluminum chloride crystal to obtain the metallurgical-grade alumina. The method is simple, the procedure is easy to be controlled, the extraction efficiency of alumina is high, the production coast is low, and the product quality is steady.

Abstract: A vertical ring magnetic separator for de-ironing of coal ash comprises a rotating ring (101), an inductive medium (102), an upper iron yoke (103), a lower iron yoke (104), a magnetic exciting coil (105), a feeding opening (106), a tailing bucket (107) and a water washing device (109). The feeding opening (106) is used for feeding the coal ash to be de-ironed, and the tailing bucket (107) is used for discharging the non-magnetic particles after de-ironing. The upper iron yoke (103) and the lower iron yoke (104) are respectively arranged at the inner and outer sides of the lower portion of the rotating ring (101). The water washing device (109) is arranged above the rotating ring (101). The inductive medium (102) is arranged in the rotating ring (101).

Abstract: Provided a method for preparing metallurgical-grade alumina by using fluidized-bed fly ash, comprising: a) removing iron by wet magnetic separation after crushing the fly ash; b) reacting the fly ash after magnetic separation with hydrochloric acid to obtain a hydrochloric leachate; c) passing the hydrochloric leachate through macro-porous cationic resin to deeply remove iron to obtain a refined aluminum chloride solution; d) concentrating and crystallizing the refined aluminum chloride solution to obtain an aluminum chloride crystal; and e) calcining the aluminum chloride crystal to obtain the metallurgical-grade alumina. The method is simple, the procedure is easy to be controlled, the extraction efficiency of alumina is high, the production coast is low, and the product quality is steady.

Abstract: Disclosed is a method for extracting gallium from fly ash, which comprises the following steps: crushing the fly ash and removing Fe by magnetic separation; then dissolving it by using hydrochloride acid (2) to obtain hydrochloric acid leachate; adsorbing gallium in the hydrochloric acid leachate with macro-porous cationic resin, followed by eluting to obtain the eluent (5) containing gallium; adding sodium hydroxide (6) solution into the eluent containing gallium to react and obtaining sodium metaaluminate solution containing gallium (8); introducing CO2 into the sodium metaaluminate solution containing gallium (8) for carbonation, followed by separating gallium from aluminum and obtaining aluminum-gallium double salt (15) with the gallium to alumina mass ratio being more than 1:340; adding the aluminum-gallium double salt (15) into sodium hydroxide (17) to react, followed by alkalinity-adjustment concentration to obtain alkali solution containing gallium and aluminum; electrolyzing (10) the alkali solution

Abstract: A vertical ring magnetic separator for de-ironing of coal ash comprises a rotating ring (101), an inductive medium (102), an upper iron yoke (103), a lower iron yoke (104), a magnetic exciting coil (105), a feeding opening (106), a tailing bucket (107) and a water washing device (109). The feeding opening (106) is used for feeding the coal ash to be de-ironed, and the tailing bucket (107) is used for discharging the non-magnetic particles after de-ironing. The upper iron yoke (103) and the lower iron yoke (104) are respectively arranged at the inner and outer sides of the lower portion of the rotating ring (101). The water washing device (109) is arranged above the rotating ring (101). The inductive medium (102) is arranged in the rotating ring (101).