Magnesium sulfate heptahydrate, also known as sulphobitter, bitter salt, cathartic salt, Epsom salt, chemical formula MgSO4·7H2O), is white or colorless acicular or oblique columnar crystals, odorless, cool and slightly bitter. After heat decomposition, the crystalline water is gradually removed to anhydrous magnesium sulfate. It is mainly used in the manufacture of fertilizer, leather, printing and dyeing, catalyst, papermaking, plastics, porcelain, pigments, matches, explosives and fireproof materials. It can be used for printing and dyeing thin cotton cloth and silk, as a weight agent for cotton silk and filler for kapok products, and used as Epsom salt in medicine.
Physical properties:
Appearance and properties: belongs to rhombic crystal system, for four corners granular or rhombic crystal, colorless, transparent, aggregate for white, rose or green glass luster. The shape is fibrous, acicular, granular or powder. Odorless, bitter taste.
Solubility: Easily soluble in water, slightly soluble in ethanol and glycerol.
Chemical properties:
Stability: Stable in the humid air below 48.1 ° C. It is easy to accommodate in the warm and dry air. When it is higher than 48.1 ° C, it loses a crystalline water and becomes magic sulfate. At the same time, a magnesium sulfate is precipitated. At 70-80 ° C, it loses 4 crystal water, loses 5 crystal water at 100 ° C, and lost 6 crystal water at 150 ° C. At 200 ° C Magnesium -like water sulfate, dehydrated material is placed in a humid air to re -absorb water. In the saturated solution of magnesium sulfate, the water-combined crystalline with 1, 2, 3, 4, 5, 6, and 12 water can be crystal. In -1.8 ~ 48.18 ° C saturated aqueous solution, magnesium sulfate is precipitated, and in the saturated water solution of 48.1 to 67.5 ° C, magnesium sulfate is precipitated. When it is higher than 67.5 ° C, a magnesium sulfate is precipitated. Alien melting between ° C and magnesium sulfate of five or four water sulfate were generated. Magnesium sulfate was transformed into magnesium sulfate at 106 ° C. Magnesium sulfate was transformed into magnesium sulfate at 122-124 ° C. Magnesium sulfate converts into stable magnesium sulfate at 161 ～ 169 ℃.
Toxicity: Poisonous
PH value: 7, Neutral
Main Application:
1) Food field
As a food reinforcement agent. my country’s regulations can be used for dairy products, with a amount of 3 to 7g/kg; the amount of use in drinking fluids and milk beverages is 1.4 ～ 2.8g/kg; the maximum usage in mineral beverages is 0.05g/kg.
2) Industrial field
It is mostly used with calcium salt for wine mother water. Adding to 4.4g/100L water can increase the hardness by 1 degree. When used, it can produce bitterness and produce hydrogen sulfide odor.
Used as a tone, explosives, papermaking, porcelain, fertilizer, and medical oral laxes, etc., mineral water additives.
3) Agricultural field
Magnesium sulfate is used in a fertilizer in agriculture because magnesium is one of the main components of chlorophyll. Crops of potted plants or magnesium are usually used, such as tomatoes, potatoes, roses, etc. Magnesium sulfate has a high degree of solubility compared to other fertilizers. Magnesium sulfate is also used as bath salt.
Preparation method:
1) Method 1:
Sulfuric acid is added to natural magnesium carbonate (magnesite), carbon dioxide is removed, recrystallized, Kieserite (MgSO4·H2O) is dissolved in hot water and recrystallized, made from sea water.
2) Method 2 (Seawater leaching method)
After the brine is evaporated by the brine method, the high temperature salt is produced, and its composition is MgSO4>. 30 percent. 35%, MgCl2 about 7%, KCl about 0.5%. The bittern can be leached with MgCl2 solution of 200g/L at 48℃, with less NaCl solution and more MgSO4 solution. After separation, the crude MgSO4·7H2O was precipitated by cooling at 10℃, and the finished product was obtained by secondary recrystallization.
3) Method 3 (Sulfuric acid method)
In the neutralization tank, the rhombotrite was slowly added into the water and mother liquor, and then neutralized with sulfuric acid. The color changed from earth color to red. The pH was controlled to Be 5, and the relative density was 1.37 ~ 1.38(39 ~ 40° Be). The neutralization solution was filtered at 80℃, then pH was adjusted to 4 with sulfuric acid, appropriate seed crystals were added, and cooled 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 65% magnesia in momorrhea through filtration, precipitation, concentration, crystallization, centrifugal separation and dryness,it is made of magnesium sulfate.
Reaction chemical equation: MgO+H2SO4+6H2O→MgSO4·7H2O.
Transportation precautions: The packaging should be complete when transporting, and the loading should be safe. During transportation, ensure that the container should not leak, collapse, fall, or damage. It is strictly forbidden to mix with acids and edible chemicals. During transportation,it should be protected from sun exposure, rain and high temperature. The vehicle should be thoroughly cleaned after transportation.
Operation precautions: Closed operation and strengthen ventilation. The operator must strictly abide by the operating procedures after special training. It is recommended that operators wear self -suction filter dust masks, chemical safety protective glasses, wearing anti -poison penetration work clothes, and rubber gloves. Avoid dust. Avoid contact with acids. Light and lightly remove the packaging to prevent the packaging from being damaged. Equipped with leak emergency treatment equipment. Empty containers may be harmful residues. When the dust concentration in the air exceeds the standard, we must wear a self -suction filter dust mask. When emergency rescue or evacuation, wearing anti -virus masks should be worn.
Storage precautions: Stored in a cool, ventilated warehouse. Stay away from fire and heat. Store separately from acid and avoid mixed storage. The storage area should be equipped with suitable materials to contain the leakage.
Packing: 25KG/BAG
Post time: Apr-10-2023