Chemical and mineral, refferences GCT Groupe Chimique Tunisien (Tunisia) 13 April 2016 g2000mtd Leave a comment Project: Retubing with replacement for calenderer and tube sheets of two gas exchangers / gas SG 3504 A / B for the DAP plant in Gabes. Main contractor: SOCOMENIN Owner: GCT Groupe Chimique Tunisien (Tunisia) Year: 2015-2016