The present invention relates to a process for treating ash recovered from a recovery boiler. The process is designed to recover valuable pulping chemicals, such as potassium, sodium, carbonate, and sulfate. In the course of treating the ash, a chloride-rich purge stream is produced and includes sulfate, carbonate, potassium, and sodium that can be beneficially used in a wood pulping process. To segregate the chloride from the beneficial chemicals, the chloride-rich purge stream is directed into an anion segregation unit such as a nanofiltration or ion exchange unit. This effectively separates or removes the chloride from the purge stream and enables the beneficial chemicals to be recycled and used in the wood pulping process.