A kind of treatment method of aluminum-containing nitric acid wastewater

Abstract

The invention relates to a treatment method for aluminum-containing nitric acid wastewater, comprising the steps of: performing multi-effect evaporation treatment on the aluminum-containing nitric acid wastewater to obtain a concentrated solution; performing cooling and crystallization treatment on the concentrated solution to obtain a crystallization solution; and performing solid-liquid separation on the crystallization solution , to obtain the filtrate and crystal aluminum nitrate; recycle the filtrate, dissolve the crystal aluminum nitrate, and add sulfuric acid for replacement treatment to obtain nitric acid and aluminum sulfate; 11mol / L nitric acid, the volume ratio of added nitric acid to concentrate is (1.3~1.5):1. The invention effectively reduces the concentration of nitrogen and ammonia nitrogen ions in wastewater by organically combining steps such as evaporation concentration, cooling crystallization, solid-liquid separation, filtrate recovery, and sulfuric acid replacement, and solves the problem of ammonia nitrogen and total nitrogen exceeding the standard in wastewater discharge, and saves nitric acid, The cost of phosphoric acid, the aluminum sulfate obtained by replacement can also produce certain economic benefits.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a method for treating aluminum-containing nitric acid wastewater. Background technique [0002] The corrosion process in the electrode foil production process requires a large amount of mixed acid, which produces a large amount of strong acid wastewater. One of the main wastewater is aluminum-containing nitric acid wastewater. The general treatment method is to discharge it directly after neutralization. Although it can greatly reduce acidity, but There is a lot of NO 3 , NH 4 If it still exists in the ion state, it will cause the total nitrogen and ammonia nitrogen to exceed the standard seriously, which does not meet the environmental protection requirements. Contents of the invention [0003] Based on this, the purpose of the present invention is to provide a treatment method for aluminum-containing nitric acid wastewater, which can solve the problem of excess...

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Problems solved by technology

[0002] The corrosion process in the electrode foil production process requires a large amount of mixed acid, which produces a large amount of strong acid wastewater. One of the main wastewater is aluminum-containing nitric acid wastewater. The general treatment method is to discharge it directly after neutralization. Although it can greatly reduce acidity, but There is a lot of NO 3 , NH 4 It still exists in an ion state, which will cause serious excess of total nitrogen and ammonia nitrogen, which does not meet environmental protection requirements

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