Sodium metabisulfite production method

Abstract

The present invention relates to the field of production of chemical products, and in particular relates to a sodium metabisulfite production method which is as follows: sulfur is sent by compressed air into a combustion furnace for combustion at 600-800 DEG C, air addition amount is about 2 times of the theoretical amount, gas SO2 concentration is 10%-13%, after cooling dust removal and filtration, sublimed sulfur and other impurities are removed, gas temperature is reduced to about 50 DEG C, the gas is introduced into a tandem reaction barrel, mother liquor and sodium carbonate are added slowly into a pulp storage barrel, a sodium sulfite suspension generated from the sodium carbonate is dissolved, and a sodium metabisulfite crystal can be produced by successively passing through a third, a second and a first reactor for absorption reaction with SO2; sodium metabisulfite prepared by the method is high in purity, utilization rate of raw materials is high, the production process is simple and easy to operate, the mother liquor and energy can be repeatedly recycled, invalid consumption of the production process can be reduced, the purpose of energy conservation and emission reduction can be achieved, production cost is reduced, and economic benefits are improved significantly.

Description

technical field [0001] The invention relates to the field of chemical product production, in particular to a production method of sodium metabisulfite. Background technique [0002] Sodium metabisulfite (Na 2 S 2 o 5 ) is an important sulfite, which can be used as an antioxidant in food and medicine, a bleaching agent for fibers and their products, a raw material for sulfite pulp, a raw material for organic synthesis, and a reducing agent in chemical reactions. Sulfur dioxide is used for the production of sodium metabisulfite one of the main raw materials. [0003] Our country is short of sulfur and pyrite resources for sulfuric acid production. In order to meet the demand for sulfuric acid in various industries, a large amount of sulfuric acid is imported every year. The low-concentration sulfur dioxide gas produced by the decomposition of raw gypsum contains too much impurity gas with oxidizing properties, and it is easy to produce sodium sulfate by side reaction in th...

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Problems solved by technology

[0003] Our country is short of sulfur and pyrite resources for sulfuric acid production. In order to meet the demand for sulfuric acid in various industries, a large amount of sulfuric acid is imported every year. The low-concentration sulfur dioxide gas produced by the decomposition of raw gypsum contains too much impurity gas with oxidizing properties, and it is easy to produce sodium sulfate by side reaction in the production process of sodium pyrosulfite, so that the content of sodium pyrosulfite produced is low and loses economic value.