Do you know how the crystallization of magnesium sulfate heptahydrate is extracted?
Method for crystallizing magnesium sulfate heptahydrate: Adding sulfuric acid to natural magnesium carbonate (magnesite), removing carbon dioxide, recrystallizing, and dissolving sulfur magnesium vanadium (Kieserite, MgSO4·H2O) in hot water to recrystallize , made from sea water.
Method for crystallizing magnesium sulfate heptahydrate (sea salt and bitter brine method): bitter brine is obtained from seawater, and after evaporation by halogen method, high temperature salt is produced, and its composition is MgSO4>30%, NaCI<35%, MgCl2 It is about 7% and KCl is about 0.5%.
The bitter brine can be immersed in a solution of 200 g/L of MgCl 2 at 48 ° C. The dissolution of NaCl is less, and the dissolution of MgSO 4 is more. After separation, the immersion liquid was cooled to 10 ° C to precipitate crude MgSO 4 · 7H 2 O, and the product was recrystallized twice to obtain a finished product.
Crystallization method of magnesium sulfate heptahydrate three (sulfuric acid method): In the neutralization tank, the rhubarb soil is slowly added to water and mother liquor, and then neutralized with sulfuric acid, the color changes from earth color to red, and the pH is controlled to 5 The relative density is 1.37 to 1.38 (39 to 40 ° Bé).
The neutralized liquid was filtered at 80 ° C, then the pH was adjusted to 4 with sulfuric acid, an appropriate amount of seed crystals was added, and the crystals were cooled to 30 ° C. After separation, the product is dried at 50-55 ° C, and the mother liquor is returned to the neutralization tank.
It can also be neutralized by a low concentration of sulfuric acid and a bituminous earth having a magnesium oxide content of 65%, filtered, precipitated, concentrated, crystallized, centrifuged, and dried to obtain magnesium sulfate heptahydrate.
Reaction chemical equation for the crystallization of magnesium sulfate heptahydrate: MgO+H2SO4+6H2O→MgSO4·7H2O
