PROCESS FOR MANUFACTURING LUMINESCENT EUROPIUM-ACTIVATED YTTRIUM MATERIAL Russian patent published in 1994 - IPC

FIELD: filling agent for manufacture of greenhouse-purpose polyethylene film. SUBSTANCE: aqueous yttrium-europium slurry with solid-water ratio of 1: 0.3-0.6 is mixed together with aqueous solution containing 40-45 % by weight of oxalic acid and 5-6 % by weight of lithium hydroxide based on total amount of yttrium and europium, with their weight ratio being 1: 1-1.5. The resulting reaction is evaporated, the resulting residue is dried to powder. Thereafter, the resulting powder is treated by calcining it for 1-1.5 hrs in two stages. First, the powder is calcined at 600-650 C, and then, at 1250-1300 C, with the intermediate cooling of the product conducted at each stage of heat treatment. EFFECT: allows the step of treatment with nitric acid to exclude, decreased amount of oxalic acid to be used in production process. 1 ex