In the chemical pulping process, cooking liquor (spent liquor) that is separated from the washed stock goes through an evaporation process to form black liquor. The black liquor becomes fuel for the recover boiler. The resulting furnace smelt is dissolved to form green liquor. After a clarification process (removal of insoluble material,) the green liquor is fed into a lime slaker where it mixes and reacts with lime. White liquor is produced, which in turn is used in the pulp cooking process. The reaction in the slaker takes place at temperatures around 185- 195°F. Overheating of green liquor does not improve causticizing reaction efficiency and presents the risk of boil over.