Magnesium sulfate heptahydrate Property

Melting point:

1124°C

Density 

2.66

vapor density 

<0.01 (vs air)

vapor pressure 

<0.1 mm Hg ( 20 °C)

storage temp. 

Store at +5°C to +30°C.

solubility 

H₂O: 1 M at 20 °C, clear, colorless

form 

Solid

Specific Gravity

1.68

color 

White

PH

5.0-8.0 (25℃, 50mg/mL in H2O)

Water Solubility 

Soluble in in water and acid. Slightly soluble in alcohol and glycerol.

λmax

λ: 260 nm Amax: 0.010
λ: 280 nm Amax: 0.010

Merck 

14,5691

Dielectric constant

8.2（Ambient）

Stability:

Stable. Non-flammable. May slowly deteriorate in contact with air.

InChIKey

WRUGWIBCXHJTDG-UHFFFAOYSA-L

LogP

-1.031 (est)

CAS DataBase Reference

10034-99-8(CAS DataBase Reference)

NIST Chemistry Reference

magnesium sulfate heptahydrate(10034-99-8)

EPA Substance Registry System

Magnesium sulfate heptahydrate (10034-99-8)

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

24/25-36-26

WGK Germany 

1

RTECS 

OM4508000

TSCA 

Yes

HS Code 

28332100

Toxicity

man,TDLo,oral,183mg/kg/4H-I (183mg/kg),GASTROINTESTINAL: "HYPERMOTILITY, DIARRHEA",Journal of Toxicology, Clinical Toxicology. Vol. 20, Pg. 107, 1983.

Hazard and Precautionary Statements (GHS)

Magnesium sulfate heptahydrate Chemical Properties,Usage,Production

Overview

Magnesium sulfate heptahydrate (MgSO4 7H2O) appears as white or colorless needle-like or inclined columnar crystal, being odorless, cool and slightly bitter with a molecular weight of 246.47, specific gravity 1.68, being easily soluble in water and slightly soluble in ethanol and glycerol. In 67.5 °C, it is soluble in its own crystal water. It can be subject to thermal decomposition with loss of four molecules of crystal water molecules at 70, 80 °C. It will lose all the crystalline water at 200 °C to become anhydrous product. In the air (dry), it is easy to be weathered into powder with heating gradually removing the crystal water molecules to become anhydrous magnesium sulfate. This product does not contain any toxic impurities. Magnesium sulfate heptahydrate is difficult to dissolve and thus being easier to weigh than anhydrous magnesium sulphate for being convenient for quantitative control in industry. It is mainly used for the manufacture of fertilizer, tanning, printing and dyeing, catalyst, papermaking, plastic, porcelain, pigments, matches, explosives and fireproof materials. It can be used for printing fine cotton, silk, as the weighting agent of cotton yarn and the filler of kapok products; as Epsom salt of medicine.

Agricultural application

Magnesium is the core element of chlorophyll, being able to enhance the reduction process of plants and improve the disease resistance. It is essential for photosynthesis. Magnesium is the activator of many enzymes, can promote carbohydrate metabolism, nucleic acid synthesis, phosphate conversion. Magnesium sulfate is a very important fertilizer, because it can provide the crop with rich nutrition. Magnesium can help crop growth and yield. Sulfur is the main component of proteins and enzymes in plants, which can promote root growth, enhance metabolism and redox in plants, and thus promote the growth of crops and increase the yield. Magnesium sulfate is a good fertilizer, it can not only provide magnesium and sulfur elements, and can also make the compacted soil be loose and strong, well-developed root system and enable full absorption of nutrients so that plants can become lusher. Magnesium and other 15 elements are considered to be plant growth and high-yielding nutrients. The nutritional components and fertilizers of the plants, the nutrients (nitrogen, phosphorus and potassium) contained in traditional fertilizers are clearly insufficient to increase agricultural yields while moderate nutrient (calcium, magnesium and sulfur) and micronutrients (zinc, copper, iron, manganese, boron, molybdenum and chlorine) become less in the soil, and the lack of these nutrients can result in reduced crop yields. Magnesium has been proven to be an important source of increased productivity and agricultural production, and must be replenished in a timely manner since the excessively extraction of magnesium from the soil is the major source of this widespread disease. It can be mixed with nitrogen, phosphorus and potassium into compound fertilizer or mixed fertilizer according to different needs, and can be mixed with one or more elements into various fertilizers and photosynthetic fertilizers respectively. After the contrast practical fertilization experiment of  treatment of nine crops including rubber trees, fruit trees, tobacco leaves, potatoes and cereals, magnesium-containing compound fertilizer can make the crop grow 15-50% better than magnesium-free fertilizer.

Feed aspects

Feed grade magnesium sulfate heptahydrate can be used as a magnesium supplement in the processing of feed. Magnesium is an indispensable factor in the process and muscle contraction of livestock and poultry. It is the activator of various enzymes in livestock and poultry, and plays an extremely important role in animal metabolism and nerve function. If the animal body undergoes magnesium deficiency, it will lead to material metabolism and neurological disorders, supply disorders, affecting the growth and development of livestock and poultry, and even lead to death.

Refer to quality standards

Magnesium sulfate heptahydrate (industrial grade)
Appearance: colorless small particles of crystals
Main content: ≥ 99.5%
PH (5W/V% Sol): 5-8
Iron content (Fe): ≤ 0.0015%
Chlorine content (cL): ≤ 0.02%
Heavy metal (Pb): ≤0.001%
Arsenic content (As): ≤ 0.0002%
Water insoluble matter: ≤ 0.01%
Loss on Ignition: 48-52%
Magnesium sulfate heptahydrate (pharmaceutical grade)
Appearance: colorless small particles of crystals
Main content: ≥ 99.5%
PH (5W/V% Sol): 5-8
Iron content (Fe): ≤ 0.0015%
Chlorine content (cL): ≤ 0.01%
Heavy metal (Pb): ≤0.001%
Arsenic content (As): ≤ 0.0002%
Water insoluble matter: ≤ 0.01%
Loss on Ignition: 48-52%
Magnesium sulfate heptahydrate (food grade)
Appearance: colorless small particles of crystals
Main content: ≥ 99.5%
PH (5W/V% Sol): 5-8
Iron content (Fe): ≤ 0.0015%
Chlorine content (cL): ≤ 0.01%
Heavy metal (Pb): ≤0.001%
Arsenic content (As): ≤0.0002%
Water insoluble matter: ≤ 0.01%
Loss on Ignition: 48-52%
Magnesium sulfate heptahydrate (feed grade)
Appearance: colorless small particles of crystals
Main content: ≥ 99.5%
PH (5W/V% Sol): 5-8
Iron content (Fe): ≤ 0.0015%
Chlorine content (cL): ≤ 0.015%
Heavy metal (Pb): ≤0.001%
Arsenic content (As): ≤ 0.0002%
Water insoluble matter: ≤ 0.01%
Weight loss on Ignition: 48-52%

Toxicity

Magnesium sulfate can be taken as an internally administrated laxative. As a result of slow absorption and rapid discharge, it generally does not show toxic effects. Oral administration of large doses can cause nerve, muscle paralysis, heart failure, sometimes can cause skin diseases.

Chemical properties

Industrial magnesium sulfate generally refers to heptahydrate, appearing as colorless needle-like or inclined columnar crystal, being odorless and of bitter taste. It is easily soluble in water and slightly soluble in ethanol and glycerol.

Uses

1.    It can be used for catharsis with its saturated solution subject to topical administration.   It has anti-inflammatory, detumescence, detoxification, analgesic effect, and can inhibit the effect of central nervous system, anti-traction and antispasmodic; used as the weighing agent of printing fine cotton, cotton, silk and the filler for kapok products; it can be used for the manufacturing of grass, fertilizers, porcelain, pigments, matches, explosives and fireproof materials; can be used as the medium component in the microbial industry; supplying the magnesium for brewing additives; used as filler to enhance the thermal resistance in the leather industry; used for the production of fresh yeast, monosodium glutamate and the stabilizer of dicalcium phosphate used in toothpaste production; can also be used in cement coagulant; pulp industry, rayon and silk industry, etc. Product containing a small amount of crystal water or no crystal water can be used for the synthesis of product that contains low water content and mixed ingredients. In organic chemical industry, it can be used for desiccant and dehydrating agent for printing thin cotton, silk, as the aggravating agent of cotton and filler of kapok products.
2.    It can be used for leather industry, fertilizer, porcelain, matches, explosives, printing and dyeing, pharmaceutical and other industries
3.    It can be used for steelmaking and ironmaking
4.    Magnesium sulfate is a feed nutrition enhancer.
5.    It can be used as laxative, cholagogue, for cathartic and duodenal diversion
6.    It can be used as analysis reagents and mordant
7.    It can be used as food fortifier. China provides that it can be used for dairy products with the usage amount of 3~7 g/kg; usage amount in the beverages and milk beverages is 1.4~2.8g/kg; the maximum dose in mineral drinks should be 0.05g/kg.
8.    It can be used as nutritional supplements, curing agents, flavor enhancers, processing aids. Brewing additives for supplement the magnesium of brewing water; as a source of nutrients during fermentation to enhance the fermentation capacity; improve the flavor of synthetic wine (usage amount of 0.002%). Adjust the water hardness. In Europe for the production of "Bolton" type of beer.
9.    It is often used in combination with the calcium salt for the yeast-purpose water. Addition of 4.4g/100 water being able to increase the hardness of 1 degree with multi-use producing bitter and producing hydrogen sulfide odor.
10.    This product can be used as tanning filler. In the printing and dyeing industry, it can be used as the aggravating agent of the thin cotton. Used as paper sizing agent.
11.    Used as medicine, food, feed additives, fermentation, industry, engineering plastics, agricultural fertilizers, household chemicals, and other fields.

Production method

Sulfuric acid method: this method takes dolomite, serpentine and magnesite as raw material. Add water or mother liquor to the neutralization reactor, and then add the mixture of sulfuric acid and the bitter earth powder containing more than 85 percent of magnesium oxide in a certain proportion to the reactor for carrying out neutralization reaction, control the Ph of 5 with the concentration of 39-40 ° Bé. Stir for 30 min for thorough reaction. Its
MgO + H2SO4 + 6H2O → MgSO4 • 7H2O
The neutralization liquid is kept at 80 °C and the filtered filtrate is sent into a crystallizer, and then added with proper seed crystal, and then cooled, filtered and centrifuged. The obtained filtrate is dried at 50-55 °C to obtain magnesium sulphate. The mother liquor is returned for ingredient use.
Recrystallization: the bitter brine obtained in the salt lake is subject to natural evaporation to be condensed into crude magnesium (crude magnesium sulfate). The crude magnesium is taken as raw material, and is dissolved in water at 80-90 °C, then is clarified at 60-70 °C, cooled and crystallized at 20-25 °C, and centrifuged and dried to obtain industrial magnesium sulfate product.
Industrial magnesium sulfate is immersed in distilled water. The Ph value is adjusted with sulfuric acid. It is subject to centrifugal separation, drying dehydration and further recrystallization, made of magnesium sulfate for medical use.
Sea salt bittern method
Sea salt is subject to sunshine to obtain bittern with evaporation obtaining high-temperature salt. The composition is MgSO4> 30%, NaCI <35%, MgCl2 about 7%, KCl is about 0.5%. Bittern can be immersed in 200g/L MgCl2 solution at 48 ℃ with NaCl being dissolved less while MgSO4 being dissolved more. After separation, the immersed liquid was cooled to 10 ° C to precipitate crude MgSO4•7H2O with secondary recrystallization obtaining the finished product.
Sulfuric acid method
In the neutralization tank, the magnesia was slowly added into water and mother liquor, then neutralized with sulfuric acid, and the color changed from soil color to red. Control the Ph at 5 with the relative density being 1.37~1.38 (39~40 ° Bé). The neutralized solution was filtered at 80 °C and then the pH was adjusted to 4 with sulfuric acid. Appropriate seed crystals were added and the crystals were cooled to 30 °C. After separation, the product is dried at 50 to 55 °C, and the mother liquor is returned to the neutralization tank. We can also use low concentration of sulfuric acid for neutralization with bitter soil containing 65% of magnesium oxide content. Undergo filtration, precipitation, concentration, crystallization, centrifugal separation, drying and preparation to obtain magnesium sulfate heptahydrate.
MgO + H2SO4 + 6H2O → MgSO4 • 7H2O

Description

In addition to its use in foods as a flavor enhancer, nutrient supplement and processing aid, magnesium sulfate (as Epsom salt) is employed in over-the-counter preparations as a laxative. As a legend (prescription drug) it has been used as an anticonvulsant and electrolyte replenisher.

Chemical Properties

White or almost white, crystalline powder or brilliant, colourless crystals.

Uses

Used in preparation of magnesium standard solutions

Uses

Magnesium Sulfate is a nutrient and dietary supplement. It is soluble in water and its solutions are neutral. It exists as crystals with a cooling, saline, bitter taste. It is also termed epsom salt.

Uses

Magnesium sulfate heptahydrate has been used:

• as a component in Kreb′s Ringer buffer
• as a component in minimal medium to culture Ralstonia solanacearum
• in the preparation of maceration solution for Lamb′s lettuce cell isolation and isotonic glucose buffer

Definition

Epsomite: a mineral form of magnesiumsulphate heptahydrate,MgSO₄.7H₂O.

General Description

Magnesium sulfate heptahydrate is hydroscopic and is vulnerable to warm temperatures.

Agricultural Uses

Epsomite (MgSO₄·7H₂O), a naturally occurring mineral, has needle-like, orthorhombic crystals. It may be found in the saline efflorescence of the surface of some soils of arid regions. It is soluble in water, which makes magnesium easily available to plants. It is used as a source of magnesium in many chemical industries like paper, sugar refining, etc.
Epsom salt, MgSO₄·7H₂O(rhombic), is the commonest hydrate of magnesium sulphate. Used as a plant nutrient to overcome magnesium deficiency, epsom salt finds application in fertilizer manufacture besides being used in fireproofing cotton and in tanning leather. Epsom salt is also known to be a laxative.

Biochem/physiol Actions

Magnesium sulfate heptahydrate is used as a source of magnesium in foliar application of fertilizers to plants.