Preparation of alphacalcium sulfate hemihydrate from FGD ...
The phasetransition of FGD gypsum to αHH was conducted in a chloridefree Ca(NO 3) 2 solution under atmosphere pressure. For an easy comparison between the chloride and the nitrate system, the Ca(NO 3) 2 concentration and reaction temperature were set to be M and 95 °C, respectively, the same with those reported in the chloride system . Fig. 1a and b tracked the phase evolution in the ...