Novel techniques for removal of potassium from the recovery boiler salt cake

摘要

Closing the effluent streams in hard wood pulping results in the build up of chlorides in the plant water systems. Potassium has a synergistic behavior with chlorides in lowering the melting point of sodium sulfate and sodium carbonate which leads to sticky deposits and corrosion in the recovery boiler. Removal of potassium ions using selective ion-exchange process has been investigated. Cryptomelane type of hydrous manganese dioxide (CRYMO), which exhibits a high selectivity for potassium ion abstracion was used in this process. 90+ percent removal of potassium ions and 99 percent recovery of sodium ions was achieved. CRYMO can be regenerated and reused for removal of potassium ions from the plant water systems.