Crystal growth kinetics of calcite in a dense fluidized‐bed crystallizer

Reconsidering water scaling tendency assessment

“…Comparing the predicted results to the experimental results of Tai et al, there were only nine cases out of 50 where the predictions seem to be in disagreement with the experimental results of Tai et al 32 These differences can be classified into two categories:…”

“…For the first type of discrepancies (values in bold font), although the MLSI values are slightly Ͼ0 (0 Ͻ MLSI Ͻ 0.12), there was no evidence of precipitation. This could be explained by the fact that nucleation would be delayed beyond the 2-h mixing time fixed by Tai et al 32 in their experiments. Indeed, for low supersaturated solution (in those cases ⍀ CCM Ͻ 1.3), the germination time would be long and can easily exceed 2 h. 20 Besides the uncertainty for calculating the MLSI, this mismatching could also be explained by the experimental errors.…”

“…Part of this table is borrowed from Tai et al 32 The authors used the letters "T" and "C" to refer to the occurrence and the lack of precipitation, respectively. The Modified Langelier Saturation Index of these solutions was computed and is reported in the same table.…”

“…To delimit the calcium carbonate metastable region in which there is no spontaneous germination, Tai et al 32 carried out more than 50 experiments where CaCl 2 and Na 2 CO 3 solutions, with various concentrations and a pH of 8.5, were mixed and stirred for 2 h at 25°C.…”

Phosphorus recovery as ferrous phosphate (vivianite) from wastewater produced in manufacture of thin film transistor-liquid crystal displays (TFT-LCD) by a fluidized bed crystallizer (FBC)

“…However, CR increased with Fe/P and approached to its maximum at an Fe/P of greater than 1.75, implying that the amount of input ferrous ions associated with phosphate, should exceed that determined from the stoichiometric ratio of the nal precipitate, driving the precipitation (to maintain proper supersaturation). 39 The hydrodynamic conditions in an FBC affect the morphology and size of the obtained crystals. In this study, most of the precipitation reaction occurred at the bottom of the reactor and the nes were immobilized on the uidized seeds.…”