The use of phosphoric acid waste product for calcium sulfide production

The article studies the technological features of calcium sulfide production from phosphogypsum. To ensure the environmental safety of industrial enterprises, closed production cycles creation is necessary. One of the criteria for "green" technologies is industrial waste recycling. Phosphogypsum formed during the orthophosphoric acid production from apatite raw materials by sulfuric acid method can be classified as large-tonnage waste. Phosphogypsum can be considered a mineral with zero mining costs and zero feedstock to produce valuable products. The synthesized materials are characterized using a complex of modern methods such as X-ray phase analysis, and electron microscopy. An environmentally friendly precursor, sucrose, is used as a reducing agent for calcium sulfate. The recovered material is a mixture of calcium sulfate and sulfide. When illuminated with ultraviolet light, it glows yellow-orange. The article presents an integrated approach to the problem of phosphoric acid production waste disposal by marketable products production.