Magnesium sulfate heptahydrate (MgSO₄·7H₂O) is a common magnesium salt compound, commonly known as Epsom salt. Due to its diverse chemical and physical properties, it is widely used in industry, agriculture, medicine, food, and other fields. The following are its main applications:
1. Agricultural Uses
- Fertilizer: Supplies magnesium and sulfur, correcting magnesium deficiency (e.g., yellowing leaves) and promoting photosynthesis.
- Foliar Spray: Quickly delivers nutrients when sprayed on plant leaves.
- Soil Amendment: Helps neutralize acidic soils and improves crop growth conditions.
2. Medical & Health Application
- Laxative: Orally administered to relieve constipation by drawing water into the intestines (must be used as directed).
- Anticonvulsant: Intravenous (IV) magnesium sulfate treats eclampsia, preeclampsia, and hypomagnesemia.
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Topical Treatments:
- Soothes muscle pain, sprains, and inflammation (e.g., Epsom salt baths).
- It helps with minor skin conditions like acne and eczema.
3. Industrial Uses
- Textile Dyeing: Acts as a mordant, improving dye fixation on fabrics.
- Chemical Production: Used to manufacture other magnesium compounds (e.g., magnesium oxide).
- Fire Retardant: Added to flame-resistant materials.
- Leather Tanning: Assists in hide processing and hair removal.
4. Food Additive
- Nutrient Supplement: Fortifies foods with magnesium (must meet food-grade standards).
- Coagulant: Used in tofu production as an alternative to nigari or gypsum.
- Brewing Aid: Balances mineral content in fermentation.
5. Laboratory Applications
- Drying Agent: Anhydrous form absorbs moisture in organic chemistry experiments.
- Buffer Solution: Used in biochemical preparations.
6. Other Uses
- Aquarium Care: Adjusts magnesium levels for coral and aquatic plant health.
- Personal Care: Found in bath salts for muscle relaxation.
Safety Notes
- Medical use requires strict dosing to avoid side effects (e.g., diarrhea or electrolyte imbalance).
- Industrial-grade and food/pharmaceutical-grade must not be interchanged.