Properties and Overview of Magnesium

Overview:

Magnesium (Mg) is a chemical element with the symbol Mg and atomic number 12. It is the eighth most abundant element in the Earth's crust and is found naturally in various minerals, including magnesite and dolomite. Discovered in 1755 by Joseph Black and isolated by Sir Humphry Davy in 1808, magnesium plays a crucial role in both industrial applications and biological processes. Physically, magnesium is a shiny, silvery-white metal that is both light and strong. Its density is about 1.74g/cm³, making it one of the lightest structural metals available. Magnesium has a relatively low melting point of 650°C and a boiling point of approximately 1,090°C. Due to its lightweight nature, magnesium is often used in applications where weight reduction is critical. The metal is also known for its good thermal and electrical conductivity.
Chemically, magnesium is highly reactive, especially when finely divided or in powdered form. It readily oxidizes in air, forming a thin layer of magnesium oxide that protects the underlying metal from further corrosion. However, if this oxide layer is breached, magnesium can burn with a bright white flame, a characteristic that makes it useful in pyrotechnics and flares. In water, magnesium reacts slowly at room temperature, but the reaction becomes more vigorous with increasing temperature, producing magnesium hydroxide and hydrogen gas. Magnesium is also a potent reducing agent commonly used to extract other metals from their ores.
Safety considerations for magnesium primarily concern its reactivity, especially in powdered form. Magnesium dust can pose a fire and explosion hazard if it becomes airborne and is exposed to an ignition source. Therefore, handling magnesium in powder form requires precautions such as proper ventilation, using non-sparking tools, and avoiding open flames. Magnesium fires are difficult to extinguish using water or standard fire extinguishers because water can intensify the fire by producing hydrogen gas. Instead, dry sand, special class D fire extinguishers, or other inert materials are used to smother magnesium fires.

Production:

The production of magnesium primarily involves extracting from seawater or minerals such as magnesite and dolomite. Seawater extraction is one of the most common methods, where magnesium is precipitated as magnesium hydroxide by adding lime. The hydroxide is then converted to magnesium chloride, which is subsequently electrolyzed to produce metallic magnesium. Alternatively, magnesium can be produced from magnesite and dolomite through a thermal reduction process involving silicon or ferrosilicon. China is the largest producer of magnesium, followed by countries like Russia, Israel, and Kazakhstan.

Applications:

Magnesium has many applications due to its unique lightness, strength, and reactivity combination. Magnesium alloys are prized for their strength-to-weight ratio in the aerospace and automotive industries, making them ideal for components such as engine parts, gearboxes, and wheels. These alloys help reduce the overall weight of vehicles and aircraft, improving fuel efficiency. Magnesium is also used to manufacture portable electronic devices, such as laptops and cameras, where its light weight contributes to the overall portability of the devices. Additionally, magnesium is a critical component in producing aluminum alloys, enhancing strength and corrosion resistance.
In the chemical industry, magnesium compounds like magnesium oxide are used as refractory materials due to their high melting points and stability under extreme conditions. Magnesium sulfate, commonly known as Epsom salt, is widely used in agriculture to correct magnesium-deficient soils and as a therapeutic agent in medicine for its laxative and anti-inflammatory properties. However, perhaps the most significant role of magnesium is in energy production. It is essential for human health, playing a critical role in over 300 enzymatic reactions, including those involved in energy production, DNA synthesis, and muscle function. This vital component of chlorophyll in plants, which is necessary for photosynthesis, underscores the significance of magnesium in our daily lives.

Summary:

Magnesium is a versatile metal, offering a unique combination of lightness, strength, and reactivity. Its diverse applications in industry, technology, and medicine make it an intriguing element. Whether it's used in the automotive industry for its strength-to-weight ratio, in agriculture to correct magnesium-deficient soils, or in medicine for its therapeutic properties, magnesium's versatility is truly remarkable. However, its reactivity necessitates careful handling to ensure safety, particularly in industrial settings.

See a comprehensive list of atomic, electrical, mechanical, physical and thermal properties for magnesium below: