Tianya Chemical is the leading manufacturer and supplier of Sodium Metabisulfite products in China, we supply excellent quality Sodium Metabisulfite with over 20 years production and development experience.

Wet process of sodium metabisulfite using sulfur as raw material is as follows:

1. Crush the sulfur into powder and send it into the combustion furnace with compressed air for self ignition at 600-800℃. The amount of air added is about twice the theoretical amount, generating sulfur dioxide gas with a concentration of 10-13%. After cooling, dust removal, and filtration, sublimated sulfur and other impurities are removed, and the gas temperature is reduced to about 50 ℃, which is then introduced into a series reaction kettle.

2. Add sodium carbonate and water to the reaction kettle, stir to dissolve, and introduce sulfur dioxide gas for reaction until Ph is 4.1 to generate sodium bisulfite solution. The reaction formula is as follows:


Production Process of Sodium Metabisulfite

3. Add the mother liquor of sodium bisulfite to the third stage reactor, and then add soda ash solution dissolved in water for neutralization reaction until the pH is 7-8 to generate sodium sulfite solution. The reaction formula is as follows: Na2CO3+2NaHSO3=2NaSO3+CO2↑+H2O

4. The generated sodium sulfite suspension is sequentially passed through the second and first stage reactors to absorb and react with sulfur dioxide until the pH is 4.1, generating sodium bisulfite solution. When the content of sodium bisulfite in the solution reaches saturation concentration, sodium metabisulfite crystals are precipitated, and the reaction formula is as follows: Na2SO3+SO2+H2O=2NaHO3 2NaHO3→Na2SO5+H2O

The reaction is an exothermic reaction, and the reaction temperature is controlled at about 45 ℃.

5. Sodium metabisulfite crystal slurry transferred from the first stage reactor is transferred to a centrifuge for centrifugation. The mother liquor after centrifugation returns to the reaction kettle in step 2, and wet sodium metabisulfite is sent to a dryer. After drying at 160 ℃, it is the finished product. The reaction exhaust gas is absorbed by alkaline solution and then vented.