| 摘要 |
FIELD: pulp-and-paper industry. SUBSTANCE: in recovery system containing sulfur and alkali metal, settled down dust formed in exhaust-heat boiler is collected and withdrawn being dissolved in water and electrolyzed producing chlorine and hydrochloric acid in anolyte. Because dust commonly contains great amount of sodium sulfate, electrolysis also may produce sulfuric acid and sodium hydroxide. To reduce content of admixtures, pH of aqueous solution before electrolysis is adjusted to a value higher than about 10, resulting in precipitation of inorganic substances, which are separated together with flocculated and dissolved substances. EFFECT: reduced chloride content in total caustic of chemical pulp mill without environmental damage. 1 dwg, 1 tbl |
