BigPatents India

The invention describes a method of processing phosphogypsum, whereby soluble phosphorus pentoxides, free phosphoric acid and fluoride impurities, contained in phosphogypsum are significantly eliminated, so as to make it a substitute for mineral or marine gypsum in commercial and industrial applications where gypsum is used. A homogenous mixture of phospho gypsum and additives containing reactive minerals and/or industrial bi-products having bivalent elements capable of forming insoluble phosphates and gaseous fluorides are prepared on a wet/dry basis, in the ratio of 1: 100 to 50:100 by weight. The mixture is pyroprocessed in a furnace at a temperature of 150º C to 600º C for a period of 5-10 seconds to 50-60 mins., depending upon the type of pyroprocessing technique used, to form processed phosphogypsum. Drawing: NIL Total Pages: 10