Valorization of industrial by-product: Phosphogypsum recycling as green binding material

Phosphogypsum (PG) from fertilizer industry represents an environmental problem, and it is usually discharged near the fertilizer plants. This waste is commonly stored in open piles, causing environmental impacts. When PG is calcined, it acquires binding properties. This paper had the objective to evaluate the use of recycled phosphogypsum (RPG), produced by PG calcination at low temperatures, for application in civil construction. The study also evaluated the feasibility of incorporating industrial waste (red ceramic - CW, porcelain - PW, and rice husk ash - RHA) to improve sustainability and search for eco-friendly materials. Results showed that RPG had properties equivalent to commercial gypsum plaster: similar flow (workability), faster setting times (initial and final), and mechanical strength to make building components. The RPG composites with wastes also achieved mechanical properties acceptable for different uses. The results indicated that the use of RPG as a binder and RPG associated with waste is an option to wastes valorization. The process generated materials with acceptable technical characteristics for applications in building activities.