Abstract
For the actual use of a technique to accelerate apparent crystal growth rate by the adhesion of fine crystals that are suspended in the mother liquid on seed crystal surfaces, effects of origin of suspended fine crystals and surface roughness of seed crystal on the apparent crystal growth rate was examined. Under conditions of supersaturation ΔT=1–30 [K] with the amount of suspended fine crystals Nfine=2×104–7×105 [kg-solution–1], batch crystallization tests for growing one seed crystals of sodium chloride using cooling fluidized bed type crystallizer were attempted experimentally. In the experimental, the apparent crystal growth rate increased with the supersaturation [mol/kg-H2O] and amount of fine crystals Nfine [kg-solution–1] unrelated to the origin of fine crystals and the surface roughness of the seed crystal. Apparent crystal growth rate (dl/dt)AV [m/h] is showed as a equation; (dl/dt)AV= (1.07×10–2+2.90×10–8 Nfine) ΔC. By observation of the cross section of crystals grown under the high crystal growth rate of 4,780 [μm/h], it was thought that the quality of grown crystal was similar to common industrial crystals of sodium chloride. From these results, it was considered that the high apparent growth rate was obtained by increasing the fine crystals with an increase in the supersaturation
