The invention relates to a preparation method of pseudo-
boehmite, which comprises the following steps: (1) dissolving inorganic aluminum salt and
polyaluminum chloride in water to prepare an aluminum
salt solution; (2) dissolving meta-
aluminate in water, and then adding a composite pore-enlarging agent to prepare a meta-
aluminate composite solution; (3) dropwise adding the meta-
aluminate composite solution into the aluminum
salt solution to form gel, stirring while dropwise adding, and controlling the
gel forming temperature to be 60-70 DEG C; (4) adjusting the pH value of the reaction liquid to 9.0 by using
ammonia water, controlling the temperature at 85-90 DEG C, and stirring and aging for 1-2 hours; (5) after aging is completed, collecting a product, filtering and washing with water; and (6)
drying by adopting a gradient heating mode. The inorganic aluminum salt and the
polyaluminum chloride are combined, the
ammonium bicarbonate, the
urea and the PEG600-800 are compounded to serve as a pore-enlarging agent, and gradient heating is adopted for
drying, so that the specific surface area of the pseudo-
boehmite can be effectively increased, the peptizing index is improved, the pseudo-
boehmite has good compounding performance, the specific surface area is 445.8-475.2 m < 2 > / g, and the peptizing index is 98.2-99.6%.