Waste liquid treatment method of aluminum-air battery

Abstract

The invention discloses a waste liquid treatment method of an aluminum-air battery, which comprises the following steps: S1, after the discharge of the aluminum-air battery is finished, changing electrolyte into strong alkali waste liquid containing aluminum hydroxide precipitate and metaaluminate; s2, performing primary precipitation and filtration to obtain a primary solid phase and a primary filtrate; s3, washing the primary solid phase with water to obtain primary aluminum hydroxide particles, diluting the primary filtrate with a water washing solution, precipitating and filtering again to obtain a secondary solid phase and a secondary filtrate, and washing the secondary solid phase with water; and S4, adding an aluminum salt into the secondary filtrate, adjusting the pH value to be neutral, carrying out tertiary precipitation and filtration to obtain a tertiary solid phase and a tertiary filtrate, drying the tertiary solid phase to obtain secondary aluminum hydroxide particles which can be directly used as a raw material or calcined to obtain an aluminum oxide product, and drying and crystallizing the tertiary filtrate to obtain an inorganic salt product. According to the aluminum-air battery waste liquid treatment method, harmless treatment of waste liquid can be achieved, graded recycling of high-value aluminum hydroxide is achieved, and meanwhile by-products of inorganic salt products are obtained.

Description

technical field [0001] The invention relates to the technical field of metal-air batteries, in particular to a method for treating waste liquid of aluminum-air batteries. Background technique [0002] Metal-air batteries, also known as metal-air fuel cells or metal fuel cells, metal-air batteries use high-purity aluminum, magnesium and other metals as negative electrodes, oxygen as positive electrodes, and potassium hydroxide solution, sodium hydroxide solution or sodium chloride solution, etc. It is a power generation / energy storage device that directly converts chemical energy fueled by light metals such as magnesium and aluminum into electrical energy as an electrolyte. It has the advantages of high specific energy density, low cost, high safety, low thermal radiation, low noise, long storage time, long discharge life, wide adaptable temperature range, rich resources, green and pollution-free; it has huge commercial application prospects . [0003] However, the electrol...

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Problems solved by technology

[0004] In view of the above deficiencies in the prior art, the present invention provides a waste liquid treatment method for aluminum-air batteries to solve the problems that aluminum ions in the waste liquid of existing metal-air batteries cannot be completely recovered or have low recycling value.

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