Pulp and paper

Green liquor dregs dewatering

Efficient dewatering of green liquor dregs leads to lower disposal costs and higher chemical recovery.
Alfa Laval decanter centrifuges offer several benefits over traditional rotary vacuum filters when used in this application:

  • Higher chemical recovery
  • Much smaller installation space
  • Lower energy consumption
  • Continuous operation instead of in batches
  • Less need for manual labour
  • Less maintenance


The smelt from the recovery boiler is mixed with weak process water to form green liquor and passes a settling tank where impurities settle to the bottom. The dregs from the settling tank are dewatered to recover as much of the green liquor as possible and to minimize disposal costs.