Purpose. The technology is designed to produce high-purity strontium iodide from technical-grade raw materials as a component of highly efficient SrI2:Eu2+ scintillation single crystals. The technology allows to obtain cheaper raw materials for growing SrI2:Eu2+ single crystals while maintaining the quality of the final product.
Technical characteristics. The technology and the process line created on its basis allow to obtain 900 kg of high-purity strontium iodide per year.
Scope. Inorganic substance technology.
Advantages. Due to the use of technical-grade raw materials with preliminary purification, the technology allows to obtain products – high-purity strontium iodide – with significantly lower costs.
Technical and economic effect. The economic effect is 260.7 UAH per 1 ton of product.
Description. Strontium carbonate is annealed at a temperature of 1200 °C. The resulting sintered strontium oxide is ground and quenched with water, which forms strontium hydroxide octahydrate of the composition Sr(OH)2 8H2O. The resulting Sr(OH)2 8H2O is recrystallized from water three times, cooling the solution from 100 C to room temperature. Strontium iodide is synthesized using the hydrazine method: Sr(OH)_2∙8 H_2O+ I_2+1/2 N_2 H_4∙H_2 O→SrI_2 ∙6 H_2 O+1/2 N_2↑+4 1/2 H_2 O, which forms strontium iodide hexahydrate. The solution is evaporated by heating to 134 C, then cooled to room temperature. The crystals are separated from the mother liquor on a Nutsche filter. Dehydration and drying of strontium iodide are carried out in titanium ampoules in a vacuum (1.2 Pa). After cooling, the ampoule with anhydrous strontium iodide of special purity is removed from the furnace, filled with argon and the resulting anhydrous strontium iodide is poured into a quartz ampoule, filling it 2/3 full. Strontium iodide is repackaged in 1000 g ampoules made of pyrex, which are then sealed.