Magnesium Sulphate, Magnesium Sulfate Heptahydrate, Epsom Salt, Bitter Salt, 10034-99-8

Magnesium Sulphate, Magnesium Sulfate Heptahydrate, Epsom Salt, Bitter Salt, 10034-99-8

Magnesium Sulfate Heptahydrate 

1. Product Identity

2. Synonyms and Identifiers

Magnesium sulfate heptahydrate is known by various names across different industries and applications:

• Common Names: MgSO₄·7H₂O, Epsom salt, Bitter salt, Sulfuric acid magnesium salt heptahydrate

• Chemical Synonyms: Magnesium sulphate heptahydrate, Magnesium(II), sulfate, heptahydrate

• Grade-Specific Names:

  • MAGNESIUM SULFATE, HEPTAHYDRATE, REAGENT (ACS)

  • MAGNESIUM SULFATE, HEPTAHYDRATE, BIO-REFINED

  • MAG-BIND EQUIPURE LIBR

• Commercial Names: Crystalline magnesium sulfate, Magnesium sulfate 7H₂O XTL

• InChI: InChI=1/Mg.H2O4S.7H2O/c;1-5(2,3)4;;;;;;;/h;(H2,1,2,3,4);7*1H2/q+2;;;;;;;;/p-2

• InChI Key: WRUGWIBCXHJTDG-UHFFFAOYSA-L

3. Physicochemical Properties

4. Solubility Information

5. Thermal Behavior and Stability

Magnesium sulfate heptahydrate loses its water of crystallization progressively when heated:

• Below 47°C: Stable

• At 47°C: Begins to lose 1 molecule of crystal water

• At 70-80°C: Loses 4 molecules of crystal water

• At 100°C: Loses 5 molecules of crystal water

• At 120°C: Loses 6 molecules of crystal water

• Around 250°C: Transforms into anhydrous magnesium sulfate (MgSO₄).

• In Air: It effloresces in dry air, losing water and turning into a powder. It rapidly absorbs moisture in humid air (hygroscopic).

6. Production Methods

Magnesium sulfate heptahydrate can be produced through several methods:

1. Sulfuric Acid Method (with Magnesite/Magnesium Oxide):

• Magnesium oxide (MgO content ≥ 85%) or magnesite (magnesium carbonate) is placed in a neutralization reactor.

• Water and sulfuric acid (H₂SO₄) are added slowly under controlled conditions.

• Reaction: MgO + H₂SO₄ + 6H₂O → MgSO₄·7H₂O

• The pH is adjusted to 5, stirred, and filtered at 80°C.

• The filtrate is sent to a crystallizer, pH adjusted to 4, seed crystals are added, and it is cooled to 30°C for crystallization.

• Crystals are separated by centrifugation and dried at 50-55°C.

2. Bitter Halogen Method (from Seawater):

• Bitter halogen (bittern) obtained as a byproduct of seawater salt production is used.

• The bittern is dissolved in a MgCl₂ solution; impurities like NaCl are separated.

• The solution is cooled to precipitate crude MgSO₄·7H₂O, which is then purified by recrystallization.

3. Chemical Purification:

• Industrial-grade magnesium sulfate is dissolved in purified water.

• The pH is adjusted with sulfuric acid.

• Decolorization is performed using activated carbon.

• High-purity (pharmaceutical grade) product is obtained through filtration, crystallization, and drying.

7. Specifications and Quality Grades

Magnesium sulfate heptahydrate is produced in various grades to meet different industrial requirements:

8. Applications and Uses

Magnesium sulfate heptahydrate has an extremely wide range of applications:

1. Agriculture and Fertilizer:

• Magnesium Fertilizer: Magnesium is the core element of chlorophyll and essential for photosynthesis. It acts as an activator for enzymes involved in carbohydrate metabolism, nucleic acid synthesis, and phosphate conversion in plants.

• Sulfur Source: Sulfur is a major component of proteins and enzymes in plants, promoting root growth.

• Yield Increase: Fertilizers containing magnesium can increase crop yields by 15-50% compared to those without magnesium (based on trials with rubber trees, fruit trees, tobacco, legumes, potatoes, and cereals).

2. Animal Feed (Feed Additive):

• Used as a magnesium supplement in feed processing.

• Magnesium is essential for bone formation and muscle contraction in livestock and poultry.

• It is an activator of various enzymes and plays a critical role in material metabolism and neural function.

• Magnesium deficiency can lead to growth retardation, neurological disorders, and even death.

3. Medical and Pharmaceutical:

• Laxative: Used orally as a laxative (Epsom salt).

• Anti-inflammatory: Applied externally as a compress (saturated solution in warm water) to reduce inflammation, swelling, bruises, and pain.

• Antidote: Used as an antidote for barium salt poisoning.

• Other Effects: Has central nervous system depressant, anticonvulsant, and antispasmodic effects.

• Warning: Overdose (blood magnesium levels exceeding 20 mg/100g) can lead to deep anesthesia, drowsiness, coma, slowed heart rate, and low blood pressure. Acute poisoning is treated with calcium preparations.

4. Food Industry (Food Additive):

• Nutritional Supplement: As a source of magnesium.

• Firming Agent: For texture in canned vegetables.

• Flavor Enhancer: Improves flavor in some beverages.

• Processing Aid: Used in brewing (especially "Burton-type" beers) as a magnesium supplement during fermentation to improve yeast performance.

• Usage Limits (based on regulations):

  • Dairy products: 3-7 g/kg

  • Drinking liquids and milk beverages: 1.4-2.8 g/kg

  • Mineral waters: 0.05 g/kg

5. Industrial Applications:

• Leather Industry: Used as a filler in tanning to enhance heat resistance.

• Textile and Dyeing: Acts as an alkali-resistant agent for dyeing fine cotton cloth and silk; used as a weighting agent.

• Paper Industry: Used in paper sizing.

• Chemical Industry: Raw material for producing other magnesium salts (magnesium stearate, magnesium phosphate, magnesium oxide) and sulfates (potassium sulfate, sodium sulfate).

• Construction and Cement: Used as a coagulant aid for cement.

• Flame Retardants: Used as a flame retardant in plastics like acrylate resins, epoxy resins, polyesters, and polyurethane.

• Other: Used in manufacturing porcelain, matches, explosives, pigments, glass; as a conductive salt in electroplating; in industrial wastewater treatment.

6. Microbiology and Biotechnology:

• Component in microbial fermentation media.

• Additive in brewing (nutrient source for fermentation).

9. Toxicology and Safety

10. Upstream and Downstream Products

Raw Materials (Upstream):

• Sulfuric acid (H₂SO₄)

• Magnesium oxide (MgO) - from magnesite or bitter earth

• Magnesite (Magnesium carbonate)

Derived Products (Downstream):

• Magnesium Hydroxide

• Ammonium magnesium sulfate

• Magnesium trisilicate

• Bacillus thuringiensis (used in biopesticide production)

• Magnesium naphthenate

• Gentamicin solution (used in antibiotic production)

11. Storage and Handling

• Storage: Store in a cool, well-ventilated place. Warehouse temperature should not exceed 48°C. Protect from moisture (efflorescence and water loss can occur in air). Keep away from acids and strong oxidizing agents.

• Packaging: Lined with polyethylene plastic bag, outer plastic woven bag. Net weights are typically 25 kg, 40 kg, or 50 kg.

• Transport: Protect from rain and sun exposure during transport. Handle with care during loading and unloading to prevent package damage.

12. Reference Information

• Last Update: 2022-01-01 08:50:43 (based on source data)

• References: Merck 14,5691; RTECS OM4508000; HS Code 28332100

Magnesium Sulfate Heptahydrate 

• Epsom salt (most common traditional name)

• Bitter salt

• Magnesium sulfate 7H₂O

• MgSO₄·7H₂O

• Crystalline magnesium sulfate

• Magnesium sulphate heptahydrate

• Magnesium(II) sulfate heptahydrate

• Sulfuric acid magnesium salt heptahydrate

• Magnesium sulfate hydrate (1:1:7)

• Heptahydrate magnesium sulfate

Grade-Specific and Trade Names:

• MAGNESIUM SULFATE, HEPTAHYDRATE, REAGENT (ACS)

• MAGNESIUM SULFATE, HEPTAHYDRATE, BIO-REFINED

• MAG-BIND EQUIPURE LIBR

• Magnesium sulfate 7H₂O XTL (Crystal)

• Magnesium sulfate heptahydrate (USP/Pharm Grade)

• Magnesium sulfate heptahydrate (Food Grade)

• Magnesium sulfate heptahydrate (Feed Grade)

• Magnesium sulfate heptahydrate (Technical Grade)

Chemical Abbreviations and Codes:

• EINECS: 600-073-4

• RTECS: OM4508000

• HS Code: 28332100

• MDL: MFCD00149785

• Merck Index: 14,5691