| 摘要 |
PURPOSE:To produce high-purity barium carbonate in high efficiency, by carrying out the ion exchange of a baryte (composed mainly of BaSO4) with Na2CO3 under proper condition, and separating and removing the impurities by a conventional method. CONSTITUTION:A highly pure barium carbonate can be produced by (1) stirring a slurry of baryte powder (finer than about 100 mesh), an alkali carbonate and water (about <=100g/l concentration) in an autoclave at >=150 deg.C and separating the produced precipitate, (2) adding water to the precipitate, adjusting the pH of the resultant slurry to <=3 with a mineral acid, and separating the insoluble residue, (3) adjusting the pH of the resultant extract liquid to 6-7 with an alkali metal hydroxide, and separating and removing the produced precipitate, and (4) adding an alkali metal carbonate to the obtained filtrate to adjust the pH to 7- 12, introducing carbon dioxide gas, and collecting the produced precipitate.
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