Preparation of paper-free and fiber-free plasterboard with high strength using phosphogypsum

Abstract Solid waste phosphogypsum (PG) generated during phosphoric acid production was used as the sole raw material to prepare a new paper-free and fiber-free plasterboard. Dehydrated PG was granulated with water, press-formed and hydrated with intermittent pressing into paper-free and fiber-free plasterboards with bending strength of 14.7 MPa. The semi-hydrate gypsum is hydrated into dense and interlocking dihydrate gypsum crystals, thereby achieving a high mechanical strength. Due to the free of paper, fiber and additive, the plasterboard is effective to recycle PG and has potential to be a new-type wall material with favorable fire resistance, cost-effectiveness and environmental friendliness.