Process for recausticizing green liquor

A process for recausticizing green liquor in a sulphate or Kraft process for wood pulp production, the process comprising the following steps:

• a green liquor consisting of an aqueous solution of sodium carbonate as a major component and sodium sulphide is mixed with calcium oxide in a slaker and undergoes a reaction in a recausticizer to form an aqueous suspension containing sodium hydroxide and calcium carbonate as major components, which suspension is filtered on a first filter and subsequently filtered lime mud solids, after dilution with water in a dilution vessel, are fed over a second filter, or, are fed over the second and a third filters and filtered to separate the solids suspended therein, wherein after a first separation of calcium carbonate as the major component and calcium oxide as the minor component, the filtered lime mud solids are mixed with water to form a second aqueous suspension, and carbon dioxide is added to the second aqueous suspension at least during dilution in the dilution vessel or carbon dioxide is fed both to the dilution vessel which is associated with the second filter and also to the dilution vessel which is associated with the third filter, wherein carbon dioxide is introduced into the dilution vessel via a vessel floor of the dilution vessel.

A process for recausticizing green liquor in a sulphate or Kraft process for wood pulp production, the process comprising the following steps:

• a green liquor consisting of an aqueous solution of sodium carbonate as a major component and sodium sulphide is mixed with calcium oxide in a slaker and undergoes a reaction in a recausticizer to form an aqueous suspension containing sodium hydroxide and calcium carbonate as major components, which suspension is filtered on a first filter and subsequently filtered lime mud solids, after dilution with water in a dilution vessel, are fed over a second filter, or, are fed over the second and a third filters and filtered to separate the solids suspended therein, wherein after a first separation of calcium carbonate as the major component and calcium oxide as the minor component, the filtered lime mud solids are mixed with water to form a second aqueous suspension, and carbon dioxide is added to the second aqueous suspension at least during dilution in the dilution vessel or carbon dioxide is fed both to the dilution vessel which is associated with the second filter and also to the dilution vessel which is associated with the third filter, wherein carbon dioxide is introduced into the line leading to one of the dilution vessels in a divided manner by means of a sparger.