Technique for decomposing potassium aluminate solution seed crystal to produce aluminum hydroxide

Abstract

The invention relates to the field of alkaline medium wet metallurgy and particularly discloses a technique for decomposing potassium aluminate solution seed crystal to produce aluminum hydroxide. The technique comprises the steps of (A) pouring a potassium aluminate solution to a reactor, controlling the alkali concentration to be 200-280g / L and the caustic ratio of the solution to be 1.35-1.75, starting water bath circulating and stirring, controlling an initial temperature of decomposition to be 60-90 DEG C; (B) adding aluminum hydroxide seed crystal to a system, and stirring for decomposing, wherein the seed crystal coefficient is 0.5-4.0 and the stirring rate is 100-500rpm; and (C) cooling the decomposition system to 40-50 DEG C, after seed crystal decomposition reaction is terminated, stopping water bath circulating and stirring, and filtering and separating to obtain a seed pregnant solution and an aluminum hydroxide product. According to the method, the decomposition rate can reach 70% under an operation condition, and is much higher than 55% seed crystal decomposition efficiency of a traditional sodium aluminate system; and meanwhile, the product is high in purity, good in shape and form and large in particle size.

Description

technical field [0001] The invention relates to the field of alumina production in alkaline medium hydrometallurgy, in particular to a process for producing aluminum hydroxide by decomposing potassium aluminate solution seed crystals. Background technique [0002] Potassium resources can be divided into water-soluble potassium resources and water-insoluble potassium resources. The world's proven industrial reserves of water-soluble potassium resources are 20 billion tons K 2 More than O, but the distribution is very uneven. More than 90% of the reserves are mainly distributed in Canada, Russia, Belarus, France, Germany, the United States, Israel, Jordan and other countries, and the grade is relatively high. However, in most developing countries and regions such as Asia and Latin America, the potash reserves are very small and the grade is low. Relatively speaking, water-insoluble potassium mineral resources are very rich and widely distributed. Various types of potassium-be...

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Problems solved by technology

The above studies are all based on sodium aluminate solutions, so further research is needed on the decomposition of potassium aluminate solution seeds

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