Manufacturing Method of Sodium Sulfite
I. Introduction
Sodium sulfite is an important inorganic salt, which is widely used in the fields of chemical industry, light industry, textile, printing and dyeing, papermaking, medicine and so on. It has the properties of reducing, bleaching and antiseptic, and can be used as bleaching agent, antiseptic, antioxidant and so on. Therefore, it is of great significance to study the manufacturing method of sodium sulfite for improving product quality, reducing production cost and promoting industrial development.
II. Properties and Uses of Sodium Sulfite
Sodium sulfite is a white crystalline powder, easily soluble in water, slightly soluble in alcohol. It has strong reducing properties and can be used as bleaching agent in textile, printing and dyeing, paper making and other industries. In addition, sodium sulfite also has antiseptic and antioxidant properties, can be used as food additives and chemical raw materials.
III. Manufacturing method of sodium sulfite
1. Absorption method
The absorption method is to pass the sulfur dioxide gas into the absorbing liquid, so that it reacts with the alkali absorber in the absorbing liquid to generate sulfite, and then go through the process of crystallization, separation, drying and other processes to produce sodium sulfite. Commonly used absorbents are sodium hydroxide, sodium carbonate and so on. This method has the advantages of simple process, convenient operation and low cost, but the generated sodium sulfite has lower purity and contains more impurities.
2. Sulphurized alkali method
Sulphurized alkali method is to react sulphurized alkali with sulphuric acid to generate sodium sulphite and sodium hydrosulphide, and then produce sodium sulphite through crystallization, separation, drying and other processes. This method has the advantages of high product purity and good quality, but the production cost is higher and the equipment corrosion is more serious.
3. Reduction method
Reduction method is the method of reducing sodium sulfate to sodium sulfite, and the commonly used reducing agents are sulfur, sodium bisulfite, etc. This method has the advantages of high purity and good quality, but the production cost is higher, and the equipment corrosion is more serious. This method has the advantages of high product purity and high yield, but the operation is more complicated and requires strict control of the reduction conditions.
Four, the manufacturing process of sodium sulfite
1. Absorption process
Absorption process mainly includes absorption, crystallization, separation, drying and other processes. The specific process is as follows: pass the sulfur dioxide gas into the absorption liquid containing sodium hydroxide or sodium carbonate, the reaction generates sodium sulfite, and the finished product is obtained after crystallization, separation, drying and other processes. The process of alkali sulfide method mainly includes reaction, crystallization, separation, drying and other processes. The specific process is as follows: Sodium sulfite and sodium hydrosulfide are generated by reacting alkali sulfide with sulfuric acid, and the finished products are obtained after crystallization, separation, drying and other processes. Reduction process
3. Reduction process
Reduction process mainly includes dosing, reduction, crystallization, separation, drying and other processes. The specific process is as follows: mix sodium sulfate with reducing agent, carry out reduction reaction at a certain temperature to generate sodium sulfite, and get the finished product after crystallization, separation, drying and other processes.
V. Precautions for the manufacture of sodium sulfite
1. Strictly control the quality of raw materials to ensure the purity of the product;
2. Strengthen the maintenance and upkeep of the equipment to reduce the equipment failure;
3. Strictly carry out the operating procedures to ensure the safety of the production;
4. Strengthen the management of the production environment to prevent pollution.
VI.CONCLUSION
Sodium sulfite, as an important chemical raw material, is widely used in various fields. It is of great significance to study its manufacturing method to improve product quality, reduce production cost and promote industrial development. In the actual production process, suitable manufacturing methods and processes should be selected according to specific conditions, and the operating conditions and product quality of each link should be strictly controlled to ensure the production of sodium sulfite products that meet the requirements.
