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Preparation method of sodium sulfite

A technology of sodium sulfite and sodium bisulfite, applied in the field of industrial chemical industry, can solve the problems of high cost, easy to produce by-products, low purity of sodium sulfite, etc., and achieve the effect of ensuring absorption

Active Publication Date: 2021-06-11
宣城市楷昂化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] Although the traditional preparation method of sodium sulfite has simple raw materials and skilled technology, the cost is very high, and a large amount of carbon dioxide waste gas will be generated. In addition, the intermediate product NaHSO 3 The reaction with sodium hydroxide, the amount of sodium hydroxide is not easy to control accurately, and part of NaHSO will be mixed in the final product solution 3 , the reaction with sodium hydroxide The traditional preparation method of sodium sulfite will produce a large amount of waste gas in the production process, and it is easy to produce by-products
In the prior art, when sulfur dioxide waste gas is used to prepare sodium sulfite, sodium sulfate is often mixed in the preparation process of other sodium sulfite, and the purity of sodium sulfite is low

Method used

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  • Preparation method of sodium sulfite

Examples

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Effect test

Embodiment 1

[0027] A preparation method of sodium sulfite, comprising the following steps:

[0028] (1) Use an absorption tower to collect flue gas from sulfuric acid production, and then fill the collected flue gas into sodium hydroxide solution to obtain the first mixed liquid. The temperature of the sodium hydroxide solution is 30°C, and the first mixed liquid The Ph value is 7.5, (the temperature of the sodium hydroxide solution is limited mainly to improve the dissolution rate of sulfur trioxide in sodium hydroxide. At room temperature, sulfur trioxide is liquid and sulfur dioxide is gaseous, so it can be guaranteed The sulfur trioxide contained in the sulfur dioxide is completely absorbed), the sodium hydroxide solution is to remove the iron oxide dust particles that may be contained in the flue gas, generate iron hydroxide precipitation, and at the same time make the sulfur dioxide and sulfur trioxide absorbed by the sodium hydroxide solution;

[0029] (2) Filter the first mixed li...

Embodiment 2

[0038] A preparation method of sodium sulfite, comprising the following steps:

[0039] (1) Use an absorption tower to collect flue gas from sulfuric acid production, and then fill the collected flue gas into sodium hydroxide solution to obtain the first mixed solution. The temperature of the sodium hydroxide solution is 35°C, and the first mixed solution The pH value is 9.5, and the sodium hydroxide solution is used to remove iron oxide dust particles that may be included in the flue gas, to form iron hydroxide precipitation, and to make sulfur dioxide and sulfur trioxide be absorbed by the sodium hydroxide solution;

[0040] (2) Filter the first mixed liquid, and obtain the second mixed liquid after solid-liquid separation;

[0041] (3) Put the second mixed solution into a reaction vessel with an air guide tube, then add sulfuric acid until no more gas is generated, and collect the sulfur dioxide gas generated by the reaction;

[0042] (3) Weighing the mass of the collected...

Embodiment 3

[0046] A preparation method of sodium sulfite, comprising the following steps:

[0047] (1) Use an absorption tower to collect flue gas from sulfuric acid production, and then fill the collected flue gas into sodium hydroxide solution to obtain the first mixed solution. The temperature of the sodium hydroxide solution is 32°C, and the first mixed solution Ph value is 8.5;

[0048] (2) Filter the first mixed liquid, and obtain the second mixed liquid after solid-liquid separation;

[0049] (3) Put the second mixed solution into a reaction vessel with an air guide tube, then add sulfuric acid until no more gas is generated, and collect the sulfur dioxide gas generated by the reaction;

[0050] (3) Weighing the mass of the collected sulfur dioxide, washing the sulfur dioxide into the first sodium carbonate solution to obtain a sodium bisulfite solution;

[0051] (4) add the second sodium carbonate solution in the sodium bisulfite solution described in step (3), obtain sodium su...

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Abstract

The invention provides a preparation method of sodium sulfite, and relates to the technical field of industrial chemical engineering. The preparation method of sodium sulfite comprises the following steps: (1) collecting flue gas for preparing sulfuric acid, and then filling the collected flue gas into a sodium hydroxide solution to obtain a first mixed solution; (2) filtering the first mixed solution, and performing solid-liquid separation to obtain a second mixed solution; (3) putting the second mixed solution into a reaction container with a gas guide tube, and then adding sulfuric acid to react to generate sulfur dioxide; (3) weighing the mass of the collected sulfur dioxide, and adding the sulfur dioxide into the first sodium carbonate solution to obtain a sodium hydrogen sulfite solution; (4) adding a second sodium carbonate solution into the sodium hydrogen sulfite solution in the step (3), and completely reacting to obtain a sodium sulfite solution; and (5) carrying out evaporative crystallization on the sodium sulfite solution to obtain sodium sulfite crystals. Sodium sulfite with the purity of 97.6% or above can be obtained, and no complex intermediate product is generated in the whole process.

Description

technical field [0001] The invention relates to the field of industrial chemical technology, in particular to a preparation method of sodium sulfite. Background technique [0002] Sodium sulfite is a relatively mature inorganic chemical product in the inorganic salt industry, and is widely used in many industries: as a deoxidizer and bleaching agent in the printing and dyeing industry; as a developer in the photosensitive industry; as a developer in the organic chemical industry [0003] As a reducing agent; used as a preservative and loosening agent in the food industry; used as a reducing agent in the inorganic chemical industry; used as a wood removal agent in the paper industry, and also used in the electronics industry, electroplating industry, and spice industry The traditional industrial production methods of sodium sulfite mainly adopt methods such as soda ash absorption of sulfur dioxide, cold crystallization and the like. In recent years, with the shortage of soda...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01D5/14
CPCC01D5/14C01P2006/80
Inventor 汪伟国张维帮
Owner 宣城市楷昂化工有限公司
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