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A method for recovering nitric acid from nitric acid waste liquid

A nitric acid and waste liquid technology, applied in the direction of nitric acid, nitrogen oxides/oxyacids, etc., can solve the problems of large corrosion risk, corrosion, low purity, etc., achieve good economic and social benefits, increase concentration, and reduce corrosion. Effect

Active Publication Date: 2021-11-26
GO HIGHER ENVIRONMENT GRP CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, nitric acid waste liquid is highly corrosive
Therefore, the equipment used in the recycling process of nitric acid waste liquid will be severely corroded due to the strong corrosion of nitric acid waste liquid, which will affect the service life of the equipment and increase the recovery cost of nitric acid waste liquid
Even if you choose equipment made of graphite, there is still a great risk of corrosion; when you choose other equipment with better corrosion resistance, it will increase the cost of recycling and reusing nitric acid waste liquid
In addition, the nitric acid waste liquid is directly rectified, and the recovered nitric acid solution contains more impurity ions and has a lower purity.

Method used

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  • A method for recovering nitric acid from nitric acid waste liquid
  • A method for recovering nitric acid from nitric acid waste liquid
  • A method for recovering nitric acid from nitric acid waste liquid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1-9

[0086] Embodiments 1-9 respectively provide a method for recovering nitric acid from nitric acid waste liquid, the difference lies in the different parameters in the stripping step.

Embodiment 1

[0087] The method that embodiment 1 provides from nitric acid waste liquid reclaims nitric acid, specifically comprises the following steps:

[0088] (1) Blow off:

[0089] A. 100L of the waste nitric acid liquid to be treated is passed into the stripping tower from 1 / 2 of the vertical height of the stripping tower; the concentration of nitric acid in the waste nitric acid liquid to be treated is 95%;

[0090] Near the bottom of the stripping tower, there are two sets of air inlets for the stripping gas, which are respectively the first group of air inlets and the second group of air inlets. And the position of the second group of air inlets is higher than that of the first group of air inlets.

[0091] The first group of air inlets is located near the bottom of the stripping tower, and the distance from the first group of air inlets to the bottom of the stripping tower is 1 / 18 of the vertical height of the stripping tower. The two air inlets in the first group of air inlets...

Embodiment 10-16

[0127] Embodiments 10-16 respectively provide a method for recovering nitric acid from nitric acid waste liquid, which is different from Embodiment 3 in that the parameters in the rectification step are different. The parameters of the method for recovering nitric acid from nitric acid waste liquid provided by embodiment 3 and embodiments 10-16 respectively are shown in table 4.

[0128] Every parameter in the method that table 4 embodiment 3 and embodiment 10-16 provide

[0129]

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Abstract

The application relates to the technical field of industrial waste acid treatment, and specifically discloses a method for recovering nitric acid from nitric acid waste liquid. It specifically includes: passing the waste nitric acid liquid to be treated into the stripping tower; then controlling the stripping gas to pass from the bottom of the stripping tower from bottom to top, and the stripping gas passes through and strips off the waste nitric acid liquid to be treated to obtain the treated nitric acid waste liquid; the gas produced by stripping is passed into the neutralized aqueous solution; the nitric acid waste liquid obtained above is passed into the rectification tower, and a dehydrating agent is added to the treated nitric acid waste liquid to carry out rectification reaction; The gas generated by the distillation reaction is passed into the condensation tower, condensed and recovered to obtain a concentrated nitric acid solution and the remaining gas; the remaining gas is passed into the spray tower, and pure water is passed into the spray tower to obtain a dilute nitric acid solution, which is absorbed by the tail gas system for exhaust gas treatment. The method provided by the present application can effectively remove fluoride ions in nitric acid waste liquid, and can effectively increase the concentration of recovered concentrated nitric acid solution at the same time.

Description

technical field [0001] The application relates to the technical field of industrial waste acid treatment, more specifically, it relates to a method for recovering nitric acid from nitric acid waste liquid. Background technique [0002] With the development of the solar energy industry and the semiconductor industry, the amount of acid waste liquid generated is increasing rapidly, and nitric acid waste liquid is one of the more common acid waste liquids. However, since the nitric acid waste liquid contains a large amount of unreacted nitric acid, if it is directly discharged, it will not only cause serious environmental pollution, but also cause a great waste of a large amount of unreacted nitric acid in the nitric acid waste liquid. The recycling and reuse of nitric acid waste liquid can effectively reduce the production cost of the enterprise, and at the same time minimize the subsequent environmental pollution, which has great economic and social benefits. [0003] Howeve...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B21/46
CPCC01B21/46
Inventor 陈福泰杨艳王琼
Owner GO HIGHER ENVIRONMENT GRP CO LTD