Extraction of Alkaline Earth Metal

According to similarities in their chemical and physical characteristics, elements are grouped in a periodic table in a row-by-row and column-by-column fashion. The elements in the column are referred to as Group 2 elements, and they include the elements beryllium, magnesium, calcium, strontium, barium, and radium, amongst other elements. Because all of these elements, except for Beryllium, exhibit similar characteristics, all of the elements in this group, except Beryllium, are referred to as Alkaline Earth. 

Metals.

Carbonation 

Encouraging the reaction by increasing the temperature and pressure or using catalysts/additives can accelerate the carbonation process. For example, at 600-750°C, several hydroxyl groups were removed from serpentine crystals, amorphizing them, greatly increasing their CO2 reactivity. Aqueous mineral carbonation has been studied extensively. The Albany Research Centre’s first approach involves carbonating serpentine pre-treated with heat in aqueous solutions of 0.64 M NaHCO3 and 1 M NaCl at 150 bar CO2 at temperatures of 155°C and 185°C.

Formic acid is used in one form, but the mineral or rock holding it is crushed before it comes into contact with the solution. It is possible to grind the mineral or the rock that contains it before putting it in an acidic solution. Depending on the formic acid used in the composition, the mineral or rock containing the mineral can have an average particle size of between 1 um and 250 um. Temperatures in one variant of the aqueous composition range from 20°C to 95°C. The aqueous composition is heated to between 75°C and 85°C in a different form. Among other things, this invention proposes a technique for the indirect carbonation of carbon dioxide, in which the following processes are carried out:

To get an alkali metal or an alkaline earth metal, one can use many methods, such as contacting the mineral with an aqueous solution containing formic acid; and carbonating the alkali metal or alkaline earth metal with carbon dioxide to generate a carbonate.

Common Characteristics of Alkaline earth metals

● From left to right in the row, atomic radii decreases, whereas from top to bottom in the column, they increase (see periodic table). Consequently, alkaline earth metals have larger atomic radii as they go down the column. Because their nuclear charge is higher than alkali metals, alkaline earth metals have a smaller size than their alkali metal counterparts.

Be< Mg< Ca< Sr< Ba< Ra

● An atom’s ionisation energy, also known as the ionisation enthalpy, is the smallest amount of energy required to remove electrons from the atom’s energy shells. Alkaline earth metals have low ionisation energies because the atoms of alkaline earth metals are large, making it difficult to remove electrons from the energy shell of the metal. The trend in ionisation energy is the inverse of the trend in atomic radii; therefore, as we progress down the group, ionisation energies drop.

Be> Mg> Ca> Sr> Ba> Ra

● The tendency of an atom of one element to form a bond with an atom of another element by sharing electron pairs is known as Electronegativity. Every atom seeks to draw the shared electron pair towards itself when an atom of one element creates an association with an atom of others by swapping electron pairs. This is known as Electronegativity. As one proceeds along with the chemical elements, the Electronegativity of alkaline earth metals decreases.

Be> Mg> Ca> Sr> Ba> Ra

● Hydration energy is the amount of energy created during the hydration of one mole of ions. Since alkaline earth metals’ hydration energy decreases as atomic size increases, this means that ions’ hydration energy decreases as one progresses through the metal family.

Be> Mg> Ca> Sr> Ba> Ra

Physical Properties of Alkaline Earth Metals

● These are silvery white.

● They are soft metals.

● They have a higher boiling point than alkali metals. 

● Flammability testing can be used to determine the presence of these components since they emit various colours when exposed to flame.

● These metals can create electricity. 

● Because alkaline earth metals have a high electropositivity, they have an electropositive nature.

● When exposed to flame, magnesium, unlike the other alkaline earth metals, does not emit any visible colour.

● Therefore, they are good conductors of heat.

● The density of alkaline earth metals is greater than alkali metals.

● The density of calcium is the lowest.

● These metals are water-soluble.

Preparation of the alkaline earth metals

According to this equation for calcium, alkaline earth metals are manufactured for industrial application by electrolytic reduction of their molten chlorides, as stated in the following equation:

CaCl2 (l) → Ca (l) + Cl2 (g)

Chemical reductants can also be employed to get the elements of group 2 in addition to electrolysis. For example, using an affordable iron/silicon alloy, magnesium may be generated on a wide scale by heating a limestone called dolomite (CaCO3.MgCO3) at 1150°C with an inexpensive iron/silicon alloy. In the beginning, CO2 is emitted, leaving behind a mixture of CaO and MgO; the subsequent reduction of Mg2+ occurs:

2CaO.MgO (s) + Fe/Si → 2 Mg(l) + Ca2SiO4+ Fe(s)

Conclusion

Magnesium is utilised in the production of several types of alloys. Radium is used for cancer treatment. Calcium is used to generate calcium carbonate, which is used to make various goods such as chalk, marble, limestone, and other similar materials. When alkaline earth metals react with acids, hydrogen gas is released; this hydrogen gas may be utilised for various reasons. Alkaline earth metals are employed to produce electrochemical and photoelectric cells, among other things. Plaster of Paris, which is likewise made of calcium, is used in various applications such as decorating, designing, and fireproofing.