Alumina – The Most Common Metal in the World

Aluminum is the most abundant nonferrous metal found in nature and widely used across industries ranging from soda cans to telescope mirrors.

Aluminium rarely exists as pure form; instead it forms compounds with other elements like oxygen and silicon that are found in igneous rocks; over time this weathering leads to soil formation and the creation of minerals such as bauxite.

History

Aluminum used to be one of the world’s most precious metals until around 1800 when it became rare and valuable enough to trade for gold. Now, aluminum has become one of the world’s most common non-ferrous metals produced and refined.

Aluminium would have remained hidden forever without electricity’s development. Although found naturally, aluminum rarely occurs as pure metal. Instead, it forms compounds such as alum and aluminum oxide (Al2O3) with other elements that were widely used from ancient times to industrial revolution, particularly as dyestuff and astringent agents.

Dane Hans Christian Oersted is widely recognized for being the first to successfully isolate elemental aluminum in 1825 using electrolysis. Oersted termed his discovery alumium; this name has since been changed in English-speaking countries to match other elements like sodium and potassium that end in “ium.” Two years later, German chemist Friedrich Wohler used similar processes to produce pure aluminum powder.

Aluminum was first discovered in the early 19th century, yet it took almost 40 years for its industrial production to become profitable due to a lack of affordable power sources. After reliable electric dynamos were introduced during the latter part of this century, electrolysis again became a viable method of breaking down compound materials into their constituent elements economically.

George Raver signed an agreement in December 1889 to supply 32.5 average annual megawatts of Columbia River hydropower to ALCOA at their first Vancouver smelter – marking its inaugural use and marking the beginning of modern aluminum production in the Northwest.

ALCOA’s success was built upon innovative engineering and scientific discoveries. Prior to discovering cryolite – an inexpensive mineral which dissolves alumina – aluminum production was very expensive; before its invention the industry could not even justify existing.

Properties

Alumina (or aluminum oxide) is one of the world’s most abundant metals, occurring naturally as an alloy with silicon and oxygen in bauxite mineral that is mined from earth to line furnaces. Alumina oxide also plays a key role in some of the finest abrasives – corundum and emery are among these hard, tough forms which are widely used to polish gemstones such as rubies and sapphires, respectively; additionally it serves as raw material for producing laser crystals made out of this raw material.

Pure aluminum metal doesn’t exist naturally and requires complex chemical processes to extract. Luckily, scientists have managed to make this process relatively efficient and economical; hence its widespread usage in everything from airplanes to utensils.

Bauxite, which contains compounds of aluminum, silicon, and iron compounds, is the most prevalent aluminar material. When exposed to moist air, these compounds oxidize into alumina. When in contact with water it reacts further with itself to form hydrates containing aluminum oxide; finally heat, pressure, and agitation is used to extract this aluminar from these hydrates for extraction purposes.

Once alumina has been refined to remove its impurities, it becomes metallic and can be processed into alloys with different properties. Alloys made with alumina may be strong or lightweight depending on its use, offering excellent conductivity of heat and electricity as well as being very durable against corrosion resistance.

Though aluminum has been around for millennia, commercial forms only began appearing commercially viable until the 1800s. Researchers perfected a chemical separation process which enabled researchers to produce industrial-grade alumina, producing nontoxic metallic aluminum which is completely safe for human exposure – it has no smell or taste and features face-centered cubic crystal structure. When combined with hydrogen and oxygen it creates aluminum hydroxide which deepens colors while adding shine on paints or powdered makeup applications; additionally it can be used as an abrasive or medicine treating heartburn, acid indigestion, ulcers and gas conditions.

Chemical Composition

Aluminum is the thirteenth element in the periodic table and does not naturally exist as pure metal; rather it occurs as compounds. Since pure aluminum forms easily bonds with other elements, its discovery was relatively recent – it occurred only after English chemist Humphry Davy decomposed bauxite using an electric arc in 1824 and produced pure aluminum metal; fifty years passed before scientists learned how to produce aluminum on an industrial scale.

Bauxite, a brown, red-brown or yellow mineral, is the main source of aluminum. Extracted using the Bayer process from underground deposits using explosives, this source yields alumina which in turn is used to produce all forms of this lightweight metal.

Pure aluminum is soft and weak; when alloyed with small amounts of magnesium, copper, silicon or manganese it becomes stronger with useful properties such as machinability and resistance to atmospheric corrosion. Because of this versatility aluminum has become an important material used in aircraft, rockets, automobiles, ships and bridges.

Because aluminum has an affinity for oxygen, its interaction with it yields various oxides of different types. These oxides are amphoteric – that is, they can react with acids and alkalis without dissociating further. When dispersed into solutions with water, aluminum (III) forms double salt aluminate [Al(SO4)2]3+ which forms when pH levels increase further causing it to hydrolyze into alumina.

Aluminum can be toxic to plants and animals in aquatic environments, leading to stomach upset and kidney damage from ingestion of its salts. Aluminium also penetrates through skin pores to the bloodstream where it interferes with hormone production in women, with high concentrations in water causing fish and birds that consume them to have thin egg shells and poor development in chicks.

Aluminate vapors exposed to sunlight produce highly reflective coatings that reflect both visible and infrared radiation, without degrading under normal circumstances. They are widely used for telescope mirrors as well as decorative paper packages and toys; solar cells in photovoltaic panels use them for protection from ultraviolet rays as well. Many methods exist for purifying aluminum for commercial applications including tensile hardness testing.

Applications

Aluminum is an essential material in many applications and industries, from soda cans and kitchen foil production to aircraft fuselage construction. Aluminum’s strength, ductility and corrosion-resistance make it suitable for soda cans, kitchen foil containers and aircraft fuselage construction; its lightweight properties and exceptional strength make it suitable for civilian and military protective equipment such as armored vehicles, body armor and bulletproof windows.

Alumina powder (commonly referred to as “aluminar”, aluminium oxide), also referred to as corundum is an integral component in manufacturing electronic components like circuit boards and microchips, providing safety and electrical efficiency. Corundum’s insulating properties prevent electric current from flowing between conductors ensuring safety and electrical efficiency; corundum forms also form precious gemstones like rubies and sapphires depending on trace levels of contaminants such as chromium titanium or iron which determine their hue. Aluminar can even reach level 9 of Mohs scale hardness).

Alumina’s ability to withstand high levels of heat makes it an invaluable material in ceramic production processes, such as silicate and nitride ceramics. Aluminar can also serve as a thermal barrier or shield, protecting components against thermal shock that might otherwise lead to their failure and cause failure of otherwise useful parts.

Due to its inertness, aluminar is an ideal material for creating medical devices like stents and dental implants. It has excellent tissue nonsensitization characteristics as well as fatigue-resistance. Alumina is produced via the Bayer process from bauxite or organic corundum material and then formed to meet end application specifications through various agglomeration and thermal processing techniques.

Kloeckner Metals offers an assortment of alumina products in many shapes, sizes and grades to meet all of your project requirements. For assistance in finding the ideal material, download our aluminum spec sheet or reach out to one of our knowledgeable sales staff members today.