Method for recovering sodium nitrate from waste nitric acid

Abstract

The invention discloses a method for recovering sodium nitrate from waste nitric acid, and relates to the technical field of waste nitric acid treatment. The method comprises the following steps: S1,preprocessing the waste nitric acid: cooling the collected waste nitric acid to 22-26 DEG C, carrying out filter pressing on the waste nitric acid through a filter press to separate out solid organicmatters in the waste nitric acid, carrying out solid-liquid separation to obtain liquid-phase waste nitric acid water and solid-phase organic matter impurities, and recycling the organic matter impurities. The invention discloses a method for recovering sodium nitrate from waste nitric acid. The filter pressing, solid-liquid separation, standing and filtering operations of the collected waste nitric acid can effectively remove the organic matter impurities, then high-concentration sodium bicarbonate obtained after pulping and washing is mixed and reacted with the waste nitric acid solution, and substances generated in the reaction are few, only are carbon dioxide and water, and are easy to treat, so the utilization rate of the waste nitric acid reaches the maximum; and the price of the sodium bicarbonate is lower than that of sodium carbonate and other substances, so the recovery cost of the waste nitric acid is reduced.

Description

technical field [0001] The invention relates to the technical field of waste nitric acid treatment, in particular to a method for recovering sodium nitrate from waste nitric acid. Background technique [0002] Sodium nitrate is a kind of inorganic salt, the chemical formula is NaNO3, white solid powder, also known as Chilean saltpeter or Peruvian saltpeter (less common), the largest sodium nitrate mine in the world is located in the Atacama Desert of Chile, and can be synthesized by the following chemical formula: NaOH(aq)+HNO3(aq)→NaNO3(aq)+H2O(l) Sodium nitrate is heated to 380°C and decomposed to produce sodium nitrite and oxygen. Sodium nitrate is oxidizing and can react with lead to produce sodium nitrite and Lead oxide, also oxidize hydroiodic acid into iodine element at room temperature and form nitric oxide: After introducing hydrogen ions into sodium nitrate solution, it will show the characteristics of nitric acid: sodium nitrate is one of the components of picklin...

AI Technical Summary

Problems solved by technology

[0006] In view of the deficiencies in the prior art, the present invention provides a method for recovering sodium nitrate from waste nitric acid, which solves the problem that most of the existing waste nitric acid treatment methods are directly neutralized by soda ash, and the sodium nitrate produced is not only low in concentration , and it contains a large amount of impurities, which cannot achieve good industrial value

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