In order to use different environments of magnesium sulfate, many varieties of products are constantly innovated and developed. As a commonly used chemical product, do you know the specific production method? Let us understand together:
1. Add sulfuric acid to natural magnesium carbonate (magnesite), remove carbon dioxide, and recrystallize. It is obtained by dissolving magnesium magnesium vanadium in hot water and recrystallizing. It is prepared from seawater.
2. (Sea salt salting bittern method): The salt salt of seawater is bitter brine, and after evaporation by the brine method, high temperature salt is produced. Its composition is MgSO4> 30%, NaCI <35%, MgCl2 is about 7%, KCl About 0.5%. Bittern can be immersed in 200g / L MgCl2 solution at 48 ℃, NaCl is less soluble, and MgSO4 is more soluble. After separation, the immersion solution was cooled to 10 ° C to precipitate crude MgSO4 · 7H2O, and the product was obtained through secondary recrystallization.
3. (Sulfuric acid method): In the neutralization tank, first add the bitter soil slowly to the water and mother liquor, then neutralize with sulfuric acid, until the color changes from soil color to red, control the pH = 5, and the relative density 1.37 —1.38 (39-40 ° Bé). Filter the neutralization solution at 80 ° C, then adjust the pH to 4 with sulfuric acid, add an appropriate amount of seeds, and cool to 30 ° C for crystallization. After separation, the product is dried at 50-55 ° C, and the mother liquor is returned to the neutralization tank. It is also possible to use a low concentration of sulfuric acid and 65% of magnesium oxide to neutralize the bitter soil. After filtration, precipitation, concentration, crystallization, centrifugation, and drying, magnesium sulfate monohydrate is prepared.
镁 Magnesium sulfate monohydrate is mostly used in fertilizers, feeds, and other industries. In general production, we need to ensure the purity of the product under the guarantee of product quality, so as to improve the utilization rate.