Present Situation and Prospect of Comprehensive Utilization of Phosphogypsum

Abstract

Phosphogypsum is a by-product of the wet process of phosphoric acid production. Although the main component of phosphogypsum is calcium sulfate, it also contains a variety of impurities harmful to the environment. How to economically and comprehensively utilize phosphogypsum to turn waste into treasure has become a global problem. Since the industrialization of wet process phosphoric acid, people have been studying the comprehensive utilization of phosphogypsum, including the direct utilization of phosphogypsum for impurity removal and the reuse of phosphogypsum after dissolution and transformation. At present, the treatment of phosphogypsum is not short of technology, but the profit of phosphogypsum treatment. Recent research has found that phosphogypsum can be completely dissolved by a chemical and metallurgical cycling process and transformed into calcium and sulfur products with market competitiveness and economic benefits. These include high-quality calcium sulfate dihydrate, light calcium carbonate, and gypsum whiskers with high added value. This is another step forward for the final solution to the problem of phosphogypsum stacking endangers environmental safety.