Aluminum ore specific weight: density and weight of 1 m³

Aluminum is one of the most widespread metals on our planet, but it is not found in pure form. Chemically active Al atoms form numerous compounds with other substances. Aluminum-bearing ores rank third by volume of occurrence in the earth’s crust.

In the post-Soviet region, bauxites are considered the most suitable and widely developed raw material. Extracting aluminum from natural raw materials is a complex process that requires large amounts of electricity.

Composition of Aluminum Ore. Aluminum Ore Weight

Bauxite, a fairly complex rock, contains aluminum hydroxide compounds, oxides, silicates and Fe hydroxides, compounds of titanium, silicon and other elements. Bauxite aluminum ore may also contain calcium and magnesium carbonates, small amounts of sodium and potassium compounds, as well as vanadium, chromium and some other substances; pyrite particles may also occur.

• The chemical composition of bauxites varies widely; it depends on the mineralogical forms of Al hydroxide and impurities. The main substance forming the ore is alumina (Al2O3). Metallic aluminum is extracted from it. The second main component is iron oxide (Fe2O3). In industrial bauxites, alumina content must be more than 30%; only in this case is development economically justified.

• The appearance of bauxites is clay-like or stony rock. The structure of aluminum ores can be very diverse: dense earthy, stony, porous, with round inclusions. Bauxite color is also diverse, from white to dark red or brick-brown. Greenish-gray and almost black, yellow, variegated rocks with blue or red-violet inclusions may also occur.

• The specific weight of aluminum ore (bauxite), or its density, ranges from 1.2 g/cm3 in rocks with low silica and Fe content to 2.5-3.3 g/cm3 in heavy, dense, ferruginous, stony bauxites.

• Bauxite hardness is 2-7.

• A distinctive feature of clay-like bauxites that helps identify the rock as aluminum ore is that, when mixed with water, clay-like bauxites do not form a plastic mass.

The largest deposits of aluminum ore are in Guinea, with more than 28% of total world reserves, almost 5.3 billion tons. It is followed by Brazil, Jamaica, Australia and India. Some deposits are located almost at the surface; they are cut layer by layer and transported to processing sites. In some countries, however, aluminum ores occur very deep, and extraction takes place in mines. One of the deepest is the Russian Cheryomukhovskaya mine in the Urals. Its depth is 1550 meters.

Alumina is a loose powdery substance obtained by the Bayer process from high-quality bauxites with low silica content. But for the next stage of aluminum production, another substance is needed: cryolite. Natural cryolite reserves in the world are extremely small, so modern metallurgy uses artificial cryolite obtained by the interaction of hydrofluoric acid with aluminum hydroxide and sodium hydroxide, also known as caustic soda.

The aluminum production process consists of three main stages:

• mining aluminum ore;

• processing the rock into alumina, or aluminum oxide;

• obtaining metallic aluminum through electrolysis.

The weight of aluminum ore required to obtain one ton of aluminum reaches 4-5 tons, approximately 2 tons of alumina.