Study on the dehydration performance influences and process of the gypsum phases in phosphogypsum using autoclave
Generally speaking,there are three crystalline phases-calcium sulfate dihydrate,α-calcium sulfate hemihydrates and anhydrous calcium sulfate in the autoclave process.The phase transition of phosphogypsum and the physical properties of the products were studied at different temperatures and in different holding time in this paper.The results show that a part of phosphogypsum is dehydrated to give β-calcium sulfate hemihydrates,and then the rest of calcium sulfate dihydrate transformed into α-calcium sulfate hemihydrates together with β-calcium sulfate hemihydrates,finally changed into anhydrous calcium sulfate entirely.Meanwhile,the influences of the dehydration process and the properties of the dehydrated phase that dissolubility P and F worked on phosphogypsum were discussed.The results showed that the insoluble calcium orthophosphate and calcium fluoride produced by the P/F impurity had an influence on the morphology of calcium sulfate dehydrate.
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维普
