The principle of magnesium sulfate monohydrate production is direct reaction of concentrated sulfuric acid with light burnt powder (bitter soil powder) or crushed magnesite ore, that is, fertilizer grade magnesium sulfate monohydrate.
First, the sulfuric acid and magnesium oxide-containing mineral powder (dolomite, rhododendron, serpentine) or its calcined powder are metered in proportion; water or washing water, mother liquor is added to the neutralization tank, and the mineral powder is slowly added under stirring. Second, sulfuric acid was added to carry out the neutralization reaction, and the pH of the slurry was controlled to be 5, and the density was 1.370 to 1.384 g/cm3. Third, the neutralizing solution is maintained at 80 degrees for a certain period of time, filtered through a blade filter, and the clear liquid is driven into the crystallizer. The mixture is cooled to 30 degrees or less, centrifuged (water can be washed in a centrifuge), and the wet material is sent to a dehydration dryer to be dehydrated and dried at 200 degrees or more to obtain magnesium sulfate monohydrate.