Separation of sulphides from pulping liquors by electrodialysis

Chemistry: electrical and wave energy – Processes and products – Electrophoresis or electro-osmosis processes and electrolyte...

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204523, 204525, 204539, B01D 6144

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055363849

ABSTRACT:
A process using an electrodialysis system employing cation-selective membranes and anion-selective membranes, particularly monovalent anion-selective membranes is used to separate kraft pulping liquors into two streams; one that is rich in sulphides (to be used in the initial stage of pulping), and another that is poor in sulphides (to be used in the final stage of pulping). By separating pulping liquors in this way, the sulphur balance in the kraft process can be maintained while obtaining the benefits of modified pulping. The same electrodialytic system can be used to separate green and polysulphide liquors into sulphide-rich and sulphide-poor components.

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