Dehydration of Phosphogypsum and Neutralization of It’s Impurities in the Steam of Raised Pressure

Abstract

Wet process of impurities neutralization or their removal from phosphogypsum considerably increases the cost price of
the product. Alternative principal possibilities for the treatment of dihydrate phosphogypsum into the gypsum binder by
escaping wet processing are discussed in the paper. The pressure of saturated water steam is not a sufficient condition
initiating a complete neutralization reaction between the acidic impurities of phosphogypsum and the neutralization
admixture and determining the growth of hemihydrate gypsum crystals. Under such condition, the transfer of the
materials between particles does not take place. To achieve it, the cavities between the particles should be filled with
water. The offered case is based on the thickening of the mixture of natural moisture phosphogypsum and the ground
carbonate solid until water emission is obtained. The prepared briquettes process in the autoclave.