Method for the production of green liquor

A method for the production of green liquor in association with a causticizing process during recovery of chemicals during the manufacture of sulphate paper pulp, comprising:

• providing a smelt of chemicals principally consisting of Na2S and Na2CO3 from a soda boiler,
• providing a weak liquor that contains dissolved NaOH and CaO,
• providing a dissolving tank in which the smelt from the soda boiler is dissolved in the weak liquor in order to form a green liquor, adding a solution of NAOH to the weak liquor at a position before the weak liquor is added to the dissolving tank increase a concentration of NaOH in the weak liquor such that a fraction of the CaO, that is presently dissolved in the weak liquor, precipitates,
• maintaining a concentration of NaOR in the weak liquor under 20 g/l, and
• adding NaOH to the weak liquor in such an amount that a concentration of NaOH in the weak liquor increases at least 20%.