The invention relates to a method for preparing superfine
aluminium silicate by
bentonite, which takes the mineral
powder of the
bentonite as a
raw material and comprises the steps of
pickling, purifying, alkaline leaching, synthesizing, washing and
drying. In the
pickling step, acid liquor is added according to the weight ratio of 1:2.5 to 5.5 of the mineral
powder of the
bentonite to the acid liquor, and the mineral
powder of the bentonite and the acid liquor react for 2 to 6 hours at the temperature of 80 to 105 DEG C; in the purifying step,
potassium permanganate and
manganese sulfate which have the weight ratio of 0.7:1 are added after the pH value of
pickling filtrate is regulated to 3 to 4 by using a
sodium hydroxide solution, the adding quantity of the
potassium permanganate and the
manganese sulfate is 1 to 3 percent of the weight of the pickling filtrate, and an
aluminium salt solution is obtained by
processing; and in the alkaline leaching step, the
sodium hydroxide solution is added into a pickling
filter cake according to the weight ratio of 1:2.5 to 5.0 of the pickling
filter cake to the
sodium hydroxide solution, and the pickling
filter cake and the
sodium hydroxide solution react below the boiling temperature to obtain water glass. In the synthesizing step, the
aluminium salt solution and a water glass solution react to obtain the superfine
aluminium silicate by separating, washing and
drying. The invention has the characteristics of low production cost, low
energy consumption and good economic benefit.