| 摘要 |
Process for the production of heavy soda with a bulk density of 1.3 to 1.6 kg/l from sodium hydroxide solution, carbon dioxide and sodium bicarbonate, characterised in that a 10 to 55% sodium hydroxide solution is added in a first mixer to the circulating hot soda and reacted with injected carbon dioxide, this mixture is introduced together with moist sodium bicarbonate into the feed device, in the form of a second mixer, of a calcining kiln maintained at a temperature of 200 to 220 DEG C, a partial stream of 5 to 50% of heavy soda is discharged as the product of the process from the quantity of soda leaving the calcining kiln and the remaining quantity of soda is reused and thus recycled. The heavy soda may be used for the alkaline-oxidising digestion of chromium ores. |
