THERMAL-BEHAVIOR OF MOROCCAN PHOSPHOGYPSUM

In this article, we have examined the thermal behaviour of Moroccan ph osphogypsum in the absence of additives. We have used very diversified techniques: thermogravimetric analysis (TGA), differential thermal an alysis (DTA), infrared spectroscopy and X-ray diffraction. DTA has all owed us to point out several transformations, Moreover, TGA has shown that the dehydration can occur in one step, which confirms that the sa mple is not bihydrated. The infrared spectroscopy has allowed us to ch aracterize the water molecules of crystallization and the sulphate gro uping of phosphogypsum. (C) 1997 Elsevier Science B.V.