GLASS FOR ACTIVE PART OF CAESIUM-137 BASED IONISING RADIATION SOURCES AND METHOD FOR PRODUCTION THEREOF Russian patent published in 2013 - IPC C03C3/21 

FIELD: chemistry.

SUBSTANCE: invention relates to production of ionising radiation sources based on caesium isotopes and can be used in radioactive waste vitrification technology. The material used for the active part of the ionising radiation source based on caesium-137 is caesium-aluminophosphate glass which, besides basic components (caesium, aluminium and phosphorus oxides), contain additional components (lithium, sodium, titanium and boron oxides) in the following concentrations, wt %: Cs₂O 55.00-62.50; Li₂O 0.25-0.55; Na₂O 0.20-0.50; Al₂O₃ 14.75-15.50; P₂O₅ 21.30-25.95; B₂O₃ 0.50-1.25; TiO₂ 0.50-1.25. The technical result of the invention is lowering the glass-melting temperature and increasing chemical stability of the glass. The method of producing said glass involves mixing a caesium-137 concentrate and phosphoric acid, heating the obtained solution to 500°C at a rate of 2.5°C/min, adding to dry residue nitrates of aluminium, lithium, titanyl and boric acid, followed by step-by-step heating of the multi-component mixture to 700°C at a rate of 5°C/min, to 900°C at a rate of 2.5°C/min and to glass-melting temperature of 1150°C at a rate of 10°C/min and holding the molten glass for 2 hours.

EFFECT: glass has high chemical stability and relatively low melting temperature (1150°C); the method of producing the glass enables to reduce swelling and reduce volatility of caesium vapour by 25-30%.

2 cl, 4 tbl