gypsum powder for cement/chalk 1)whiteness 90% above, 2)fineness of 120 mesh, 3) ... initial setting 7minutes ,final setting 15 gypsum powder for cement/chalk: we are the professional manufacture for gypsum powder. we have ... setting 7 minutes, Final setting for 15 minutes. Useful: cornice, chalk, ceiling, contruction, casting, wall, plasterboard, food,medical bandage etc Packing ...