Thermal treatment of moroccan phosphogypsum S. El Issiouy, A. Atbir, S. Mançour-Billah, R. Bellajrou, L. Boukbir and M. El Hadek MATEC Web of Conferences, 3 (2013) 01030 Published online: 01 July 2013 DOI: 10.1051/matecconf/20130301030