Method for efficiently recycling valuable element in aluminum ash

Abstract

The invention discloses a method for efficiently recycling valuable elements in aluminum ash. The method comprises the following steps: carrying out wet grinding on aluminum ash and water or sig water, adjusting the pH value of slurry to be neutral, and carrying out solid-liquid separation so as to respectively obtain desalting deamination aluminum ash and a salt solution; carrying out evaporationcrystallization treatment on the salt solution so as to obtain an electrolyte salt product, adding the desalting deamination aluminum ash and an alkali liquid into a high-pressure reaction kettle according to a certain liquid-solid ratio, and carrying out a hydrothermal reaction, wherein a certain amount of hydrogen is generated in the reaction process; carrying out solid-liquid separation on theobtained slurry, so as to obtain a sodium aluminate solution and dissolved residues, wherein the sodium aluminate solution can be adopted to product an aluminum oxide or aluminum hydroxide product, and the residues can be used as a construction raw material. Due to desalting deamination treatment on the aluminum ash, nitrogen and electrolyte salt components in the aluminum ash can be sufficientlyrecycled, an inert aluminum oxide component in the aluminum ash can be efficiently dissolved in a high-pressure dissolution mode, efficient recycling of valuable elements in the aluminum ash is achieved, and a novel way is created for recycling of solid wastes such as the aluminum ash generated in industries such as electrolyte aluminum and aluminum processing.

Description

technical field [0001] The invention relates to the technical field of recycling and utilization of aluminum ash produced in electrolytic aluminum and aluminum processing technology, in particular to a method for separating and recovering ammonia, electrolyte salt and alumina from aluminum ash. Background technique [0002] Aluminum ash is a solid waste produced during the production of electrolytic aluminum or aluminum processing and smelting. It is mainly composed of cooled metal aluminum, oxides produced during high temperature processes, fluxes, and electrolyte salts. According to reports, about 20-40kg of aluminum ash is produced for every 1 ton of metal aluminum produced; about 100-250kg of aluminum ash is produced for every 1 ton of waste aluminum recycled. As the world's largest electrolytic aluminum and aluminum processing country, my country's annual output of aluminum ash is more than 3 million tons, plus the stockpile over the years, the amount reaches tens of mi...

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Problems solved by technology

The patent only proposes a theoretical treatment method, but does not fully consider many problems existing in actual production, such as: (1) the mutual coating and embedding of different phases between aluminum ash particles, and the problem that chlorine salt is not easy to elute ; (2) Al(OH) produced by aluminum nitride in aluminum ash during hydrolysis 3 Products such as AlOOH and AlOOH will wrap the raw materials and inhibit their hydrolysis process, resulting in incomplete separation of chloride salts and ammonia; (3) Due to incomplete separation of chloride salts and aluminum nitride, more impurities enter the alumina extraction process, thereby affecting Product quality; (4) Recycling and utilization of ammonia and hydrogen

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