Strontium occurs naturally in the minerals celestine and strontianite as well as, in prospect, mineral waters are considered as the important sources of Strontium extraction. Strontium is produced via electrolysis of SrCl2 smelt or, alternatively, by metallothermic reduction of SrO or SrCl2. Smelt electrolysis (85% SrCl2 + KCl or NH4Cl) is performed on nickel or iron catode at 800°C. First celestine concentrate is reduced by heated coal to SrS. After HCl treatment and dehydrating SrCl2 is obtained, which contains 0.3-0.4% K. Aluminium, silicon or ferrosilicium are used for SrO metallothermic reduction in vacuum at 1000°C. SrCl2 is reduced by Magnesium metallic in hydrogen atmosphere.
Strontianite concentrate is decomposed by roasting at 1200°C, produced SrO dissolved in water or by direct dissolving in acids.
Strontium may be also obtained by vacuum heating of SrH2 (1000°C), Sr3N2 (140-150°C) or Sr(NH3)6. Then strontium is refined by vacuum sublimation. Radioactive isotopes are produced by Sr: 88Sr(n, g) 89Sr or in cyclotron: 88Sr(d, p) 89Sr.\n |