| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of barium carbonate which is simply manufactured in high yield and particularly excellent as a raw material of a barium halidebased phosphor. SOLUTION: The manufacturing method of barium carbonate for manufacturing barium halide based phosphor is performed by mixing powder consisting essentially of barium sulfate having <=2 mm weight average particle diameter with an aqueous solution containing at least one of potassium carbonate and sodium carbonate so that the molar ratio of at least one of potassium carbonate and sodium carbonate to barium sulfate is >=1, reacting at >=40 deg.C for at least 1 hr to produce and precipitate barium halide. It is preferable to adopt at least one of a recrystallizing method by adding a solvent into the produced barium carbonate to dissolve and concentrating and recrystallizing the resultant solution or a precipitating method by adding a solvent into the produced barium carbonate and adding a flocculant into the resultant solution to precipitate impurities.
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