کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
674052 | 1459539 | 2012 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Microcalorimetric study of the transformation of CaSO4·2H2O in the 40 and 50 wt% P2O5 solutions at 80 °C Microcalorimetric study of the transformation of CaSO4·2H2O in the 40 and 50 wt% P2O5 solutions at 80 °C](/preview/png/674052.png)
A calorimetric study of the transformation of CaSO4·2H2O (gypsum) in 40 and 50 wt% of P2O5 phosphoric acid solutions is undertaken at 80 °C by dissolving increasing amounts of gypsum in the same volume of liquid. The results show a simple dissolution or its transformation into hemihydrate, CaSO4·1/2H2O, depending on the acid concentration. Kinetic schemes have been developed for these processes. The kinetic and thermochemical parameters were derived iteratively and the enthalpies were compared to experimental values.
► CaSO4·2H2O (gypsum) was dissolved in 40 and 50 wt% P2O5 solutions at 80 °C.
► Dissolution processes were realized in a C80 SETARAM calorimeter.
► The gypsum dissolution in 40 wt% P2O5 solution takes place in one step.
► Gypsum transforms into hemihydrate through a dissolution/precipitation process.
Journal: Thermochimica Acta - Volume 545, 10 October 2012, Pages 174–179