Magnesium Sulfate Heptahydrate

Brief Overview

Magnesium sulfate is an inorganic salt with the chemical formula MgSO₄. It occurs in two forms, monohydrate and heptahydrate. The heptahydrate form is MgSO₄.7H₂O and is commonly called Epsom salt. The monohydrate is MgSO₄.H₂O and is present in the form of a mineral called kieserite.

Manufacturing Process

Magnesium sulfate is often obtained from natural sources, such as minerals in geological environments. They occur by the supergene process, that is, their enrichment occurs relatively near the surface. Magnesium sulfate is an important constituent of evaporitic potassium-magnesium salt deposits. Magnesium sulfate heptahydrate occurs naturally as the mineral epsomite. Another mineral called alpersite contains copper and the heptahydrate form of magnesium sulfate.

Food Industry

Magnesium sulfate is used as a dough conditioner in baked goods. It can improve the texture and appearance of bread, cakes, and other baked products.

Medical Industry

Epsom salt is a common pharmaceutical preparation of magnesium and is used both externally and internally. Epsom salt is given orally as a saline laxative or osmotic purgative. It is the main preparation of intravenous magnesium. It is used in replacement therapy for hypomagnesemia, as an antiarrhythmic agent in cardiac arrest, and as a bronchodilator in severe asthma exacerbations. It is also given as first aid for barium chloride poisoning.

Cosmetic Industry     

Magnesium sulfate is used in bath salts and to prepare foot baths to soothe sore feet. The addition of Epsom salt increases the ionic strength and prevents temporary skin wrinkling. It also gets absorbed into the skin and reduces inflammation. It is also used in floatation therapy, where a high concentration of Epsom salt raises the bath water's specific gravity and makes the body buoyant.

Other Applications

Magnesium sulfate is used to maintain the magnesium concentration in marine aquaria, which consists of large quantities of stony corals, to stabilize the calcium ions depleted by the calcification process.