Patent ID: 6231767
Filing Date: 2001-05-15
Classification: B03B,C04B,C05B,Y02P,Y02W,Y10S

Abstract:
A process for treating thickened phosphatic clay suspensions, waste clay and phosphogypsum produced in the processing of phosphate ore by water beneficiation and chemical processing, said thickened phosphatic clay suspension having a solid content of from about 4 to about 40 percent by weight, the process comprising:mixing a sufficient amount of deflocculating agent with a thickened phosphatic clay suspension to cause deflocculation of the suspension to an extent sufficient to reduce the viscosity thereof to a value enabling the deflocculated suspension to be readily pumped from one location to another, the deflocculating agent comprising an alkali compound of a phosphorus oxide,pumping the deflocculated suspension of reduced viscosity from one location to another,separating the deflocculated suspension into a clay suspension and a phosphatic mineral and sand suspension,dissolving the non-clay minerals in the phosphatic mineral and sand suspension in dilute sulfuric acid to separate a phosphatic fraction as phosphoric acid from a sand fraction,producing a cementitious material by heating clay, phosphogypsum and sand in a kiln, andmixing the cementitious material with the clay suspension and the sand fraction in an amount sufficient to cause the formation of large silicate molecules with resultant gelling and setting of the suspensions into an inert solid material.