Method for stably preparing pseudo-boehmite under mild condition

Abstract

The invention discloses a method for stably preparing pseudo-boehmite under a mild condition. The method mainly comprises the following steps: adding ethylene glycol into an aqueous solution of sodium aluminate, uniformly stirring to obtain a clear mixed solution, putting the mixed solution into a reaction kettle, carrying out hydrothermal reaction, centrifuging, washing and drying to obtain the pseudo-boehmite. According to the invention, the preparation process of the single-phase pseudo-boehmite is expanded to a low-temperature environment system, the reaction condition is mild, the reaction time is short, and the reaction product can be more stably separated out, that is, the product is still the single-phase boehmite along with the prolonging of the reaction time. The specific surface area of the prepared pseudo-boehmite is 234.6-449.8 m < 2 > / g, the pore volume is 0.13-0.36 cm < 3 > / g, the average pore size is 2.2-4.0 nm, the pseudo-boehmite can be used as a binder and a vaccine adjuvant of aluminum silicate refractory fibers, and the roasted product gamma-Al2O3 of the pseudo-boehmite can be applied to the fields of catalysis and adsorption.

Description

technical field [0001] The invention belongs to the technical field of chemical alumina preparation, and in particular relates to a method for stably preparing pseudo-boehmite under mild conditions. Background technique [0002] Pseudoboehmite (γ-AlOOH·nH 2 O) also known as gel boehmite, boehmite colloid, pseudo-boehmite, it has excellent characteristics such as high Gibbs free energy, large porosity and high specific surface area, Widely used as catalytic materials, adsorbents, binders and vaccine auxiliaries -842.] etc., and its roasted product γ-Al 2 o 3 As a catalyst carrier, it is widely used in the field of petrochemical industry. [0003] The methods for preparing pseudo-boehmite mainly include hydrothermal method, aluminum alcohol hydrolysis method, acid-base method, sol-gel method, carbonization method, etc., among which hydrothermal aluminum alcohol method, hydrothermal aluminum salt method and hydrothermal crystallization The hydrothermal synthesis method suc...

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Problems solved by technology

The disadvantage of this method is that the pseudo-boehmite prepared at room temperature cannot exist stably, and it will change to other phases when the reaction time is prolonged, and its precipitant formamide is slightly toxic

[0004] Although the above methods have prepared pseudo-boehmite under certain conditions, pH regulators are often required in the preparation process or carried out under high-temperature hydrothermal conditions, resulting in higher preparation costs.

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