Abstract
For the purpose preventing alkaline scale from the desalination evaporator, the decomposition of carbonates in the brine was studied by adding the seed crystals to slaked lime under the following conditions: (1) apparatus; shaking bath,(2) brilie concentration; CF 2,(3) temperature; 40, 60, 80 and 100°C at the non boiling state,(4) slaked lime concenfration 1 eq. to Ca (HCO3) 2 (200ppm),(5) seed crystals; aragonite, calcite and brucite. The results were as follows:
1) Aragonite was the most effective on the decomposition of carbonates among these seed crystals.
2) Effect of aragonite on the decomposition of carbonates was increased due to the simultaneous use of slaked lime. In this case, the most effective temperature was at 40°C.
3) The values of K and A were calculated by applying Murotani's formula of velocity of crystallization ν=K(c/c0-A) to these experimental results. The values of K in non-addition and addition of aragonite were 0.22 and 0.12, and the values of A in non-addition and addition of aragonite were 0.85 and -0.65 as the saturation index of CaCO3. The value of A was decreased as result of the addition of aragonite.
