WASSERAUFSPALTUNGSVERFAHREN MITTELS ELEKTRODIALYSE

An electrodialysis water splitting processes incorporates a chromatographic separation step using an amphoteric ion exchange resin to remove contamination salts from a salt solution feedstream (18) and a base product solution (36). When the chromatographic column (20,30) is subsequently eluted with water an effective separation of the components is achieved. The separated pure salt stream is forwarded to an electrodialysis water splitter cell (24) for conversion to acid and base. The base product solution (sodium hydroxide, potassium hydroxide) (36) may be similarly purified by passing through a second chromatographic column (30) also containing an amphoteric resin to separate the base from the salt (recovered salt). The process is also applicable in a chlor-alkali process for acidifying the brine feed (82) to the electrolysis cell (80) and for producing high purity caustic from salt.