Carbonate removal from concentrated hydroxide solutions

P. Sipos, P. M. May, G. T. Hefter

Research output: Contribution to journalArticle

58 Citations (Scopus)

Abstract

Methods for routinely lowering the carbonate content of concentrated aqueous hydroxide solutions [MOH with M+ = Li+, Na+, K+, Cs+ and (CH3)4N+] to analytically negligible levels (≤ 0.2% of the total alkalinity) are described. No single method was satisfactory for all MOH. Carbonate can be removed from highly concentrated (ca. 50% w/w) NaOH solutions by filtration since Na2CO3 is almost insoluble in this medium. However, for LiOH (ca. 4 M), (CH3)4NOH (ca 4.5 M) and KOH (ca. 14 M) and less concentrated NaOH (<10 M), treatment with excess solid CaO followed by filtration gave the best results. For CsOH, which may be seriously contaminated with carbonate, the only satisfactory procedure was treatment of very concentrated soultions with excess solid Ba(OH)2. Residual calcium and barium concentrations in the decarbonated solutions were at trace levels.

Original languageEnglish
Pages (from-to)955-958
Number of pages4
JournalThe Analyst
Volume125
Issue number5
DOIs
Publication statusPublished - 2000

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Carbonates
hydroxide
carbonate
barium
Barium
Alkalinity
alkalinity
Calcium
calcium
removal
hydroxide ion
method

ASJC Scopus subject areas

  • Analytical Chemistry

Cite this

Carbonate removal from concentrated hydroxide solutions. / Sipos, P.; May, P. M.; Hefter, G. T.

In: The Analyst, Vol. 125, No. 5, 2000, p. 955-958.

Research output: Contribution to journalArticle

Sipos, P. ; May, P. M. ; Hefter, G. T. / Carbonate removal from concentrated hydroxide solutions. In: The Analyst. 2000 ; Vol. 125, No. 5. pp. 955-958.
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