Method for continuously producing pseudoboehmite by using ejector

Abstract

The invention discloses a method for continuously producing pseudoboehmite by using an ejector, belonging to the technical field of boehmite preparation. The method comprises the following steps: continuously adding a sodium metaaluminate solution into the ejector, and introducing an air-carbon dioxide gas mixture into the ejector, and forming a strong liquid flow of the sodium metaaluminate solution to be thoroughly mixed with the carbon dioxide gas; controlling the flow rates of the gas mixture and the sodium metaaluminate solution to control the temperature of the slurry generated by reaction at 25-55 DEG C and the pH value at 9.5-11; and aging the slurry, filtering, washing with water to a neutral state, and drying to obtain the pseudoboehmite. The pseudoboehmite prepared by the method has the characteristics of large specific area and pore volume, reasonable peptization, continuous production, simple technique, high production efficiency, stable product quality, low equipment investment, low energy consumption, low labor intensity and the like, is reliable in operation, is convenient to operate and maintain, and is especially suitable for producing common pseudoboehmite, superfine aluminum hydroxide or aluminum oxide.

Description

technical field [0001] The invention relates to the technical field of bauxite preparation, in particular to a method for continuously producing pseudo-boehmite by using an ejector. Background technique [0002] Pseudoboehmite, also known as monohydrate alumina, pseudo boehmite, is non-toxic, tasteless, odorless, white colloidal (wet product) or powder (dry product), with high crystal phase purity and good peptization performance , strong cohesiveness, high specific surface area, large pore volume, etc., and its water-containing state is a thixotropic gel. [0003] There are many production methods of pseudo-boehmite: Alcohol Alcohol method is often used in foreign countries at present, the product quality is high and the pore structure is easy to control, but the production cost is high and there is environmental pollution; currently the most economical and widely used in China is acid method or alkaline method. Industrial pseudo-boehmite production methods mainly include...

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Problems solved by technology

[0012] In order to solve the intermittent production of pseudo-boehmite prepared by the existing carbonization method, the problems of high labor intensity, low productivity, and large fluctuations in product quality, etc., the invention provides a method for continuously producing pseudo-boehmite by using an ejector, Including: continuously adding sodium metaaluminate solution into the ejector, and feeding the mixed gas of air and carbon dioxide into the ejector, so that the sodium metaaluminate solution forms a strong liquid flow and fully mixes with carbon dioxide gas ; Control the flow rate of the mixed gas and sodium metaaluminate solution, so that the temperature of the slurry generated by the reaction is 25-55 ° C, and the pH value is 9.5-11; the slurry is aged, filtered, washed to neutrality and dried to obtain Pseudoboehmite

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