Strontianite SrCO

Strontium metal is not found in its elemental state in nature. Its salts and oxide compounds constitute only 0.025% of the Earths crust. Strontium is found in Mexico and Spain in the mineral ores of strontianite (SrCO ) and celestite (SrSO ). As these ores are treated with hydrochloric acid (HCl), they produce strontium chloride (SrCy that is then used, along with potassium chloride (KCl), to form a eutectic mixture to reduce the melting point of the SrCl, as a molten electrolyte in a graphite dish-shaped electrolysis apparatus. This process produces Sr cations collected at the cathode, where they acquire electrons to form strontium metal. At the same time, Cl anions give up electrons at the anode and are released as chlorine gas Cl T. 

The two principal strontium minerals are its carbonate, strontianite, SrCOs, and the more abundant sulfate mineral celestite, SrS04. 

Carbonates Aragonite CaCOs, calcite CaCOs, cerussite PbCOs, magnesite MgCOs, strontianite SrCOs, witherite BaCOs... 

Strontium occurs chiefly as sulfate (celestite, SrSO,i) and carbonate (strontianite. SrCO ) although widely distributed in small concentration. The commercially exploited deposits are mainly in England. The sulfate or carbonate is transformed into chloride, and the electrolysis of die fused chloride yields strontium metal,... 

An element, not as abundant as Ba, occurring principally in the minerals strontianite (SrCOs) and celestine (SrSOd- Its compounds resemble those of Ca and Ba. Its nitrate is used in making red fire. 

Cerussite (PbCOs) is also naturally abundant and crystallizes in an orthorhombic form isomorphous with strontianite (SrCOs) and aragonite (CaCOs). PbCOs is often found with galena in ore veins because it forms when carbonate-rich waters interact with PbS in the common lead-zinc-limestone ore association (47). The derivative PbCOs Pb(OH)2, known as cemse or white lead , was the most important artificial white pigment in antiquity (3). Ceruse is made by treating naturally occurring lead compounds [mixtures of PbCOs, PbO, and... 

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