- Shandong Yifengtuo Chemical Co.,ltd
NEWS
Shandong Yifengtuo Chemical Co.,ltd
Preparation method of magnesium sulfate heptahydrate
Date：
2023-01-11 13:39
Method 1
Add sulfuric acid into natural magnesium carbonate (magnesite), remove carbon dioxide, and then recrystallize it. Dissolve Kieserite, MgSO4 · H2O in hot water and recrystallize it, and make it from seawater.
Method 2 (Seawater sunning salt bittern method)
Bittern is obtained by drying salt in sea water. After evaporation by mixing brine, high temperature salt is produced. Its composition is MgSO4>30%, NaCI<35%, MgCl2 about 7%, and KCl about 0.5%. Bittern can be dissolved in 200g/L MgCl2 solution at 48 ℃, NaCl is less dissolved, and MgSO4 is more dissolved. After separation, the leaching solution is cooled to 10 ℃, and coarse MgSO4 · 7H2O is precipitated, and the finished product is obtained through secondary recrystallization.
Method III (sulfuric acid method)
In the neutralization tank, slowly add the bitter clay into the water and mother liquor, and then neutralize it with sulfuric acid until the color changes from earth to red. Control pH=5, and the relative density is 1.37~1.38 (39~40 ° B é). Filter the neutralization solution at 80 ℃, adjust the pH value to 4 with sulfuric acid, add proper amount of crystal seeds, and cool to 30 ℃ for crystallization. After separation, the finished product is dried at 50~55 ℃, and the mother liquor is returned to the neutralization tank. Magnesium sulfate heptahydrate can also be prepared by neutralizing reaction of low concentration sulfuric acid with bitter clay containing 65% magnesium oxide, and then filtering, precipitation, concentration, crystallization, centrifugation and drying.
Reaction chemical equation: MgO+H2SO4+6H2O → MgSO4 · 7H2O
ADD:Room 02, Building 28, Community Jiaoyuan, Shengcheng street, Shouguang City.
Email: susan@yifengtuochemical.com
Susan Liu
