New dawn of solid waste resource treatment: Preparation of high-performance building materials from waste-gypsum by mechanical technology

The resourceful use of solid waste has continued. The research produced a new eco-friendly, high-strength, water-resistant building material by using the simplest mechanical method of pressing 100% phosphogypsum. The compressive strength of the blocks was higher than 80 MPa and the flexural strength was 5.5 MPa when the pressure was 300 MPa and the placing time was 5d. SEM, FTIR, TG-DTG and XRD of the products showed the blocks pressed from phosphogypsum didn't change the chemical composition of the original phosphogypsum and produce new substances at different pressures, but the increase in pressure changed the crystal structure of CaSO4·2H2O.