| 摘要 |
A multivalent metal hydroxide is separated as a solid from an alkali hydroxide or from another multivalent metal hydroxide in an electrodialytic cell. The separation process is regulated by varying the pH or concentration of alkali hydroxide in a feed compartment electrolyte by matching the rate alkali cations are fed and removed from the electrolyte. As a result, one multivalent metal cation separates as a solid in the feed electrolyte or one multivalent cation separates as a solid and one multivalent cation is ionically mobile and electrotransportable from the electrolyte. This electrodialytic method can be used to continuously regenerate sodium hydroxide etchants containing dissolved aluminum, when the dissolved aluminum is removed from the etchant as a solid and the sodium hydroxide is returned as a solution for etching.
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