摘要 |
A method to purify an aqueous solution of an alkali metal hydroxide by countercurrently contacting the ammonia and hydroxide, in a volume ratio of about 0.6 to 1 to about 1 to 1, in a packed bed. The temperature in the lower portion of an extractor in which the process is carried out is controlled and maintained within a range of at least about 155 DEG to about 170 DEG F.
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