Phosphate from Wastes Via Acid-leaching in the Presence of Methanol.
Wilemon-GM; Swanton-RG; Davis-JG; Scheiner-BJ
SME Preprint 90-145 1990 :8 pages
The Bureau of Mines has conducted investigations on extracting phosphate values from wastes generated during the mining and beneficiation of phosphate matrix. These wastes may contain up to one-third of the phosphate originally present in untreated ore. Samples of wastes were air-dried and leached using 93 pct sulfuric acid in the presence of methanol. Evidence for the formation of a calcium sulfate hemihydrate coating that hinders complete dissolution of phosphate is presented. Solid-liquid separations were enhanced when flocculation was effected using poly(ethylene oxide)(peo) in conjunction with hydroxypropyl cellulose (hpc) or hydroxyethyl cellulose (hec). A conceptual flowsheet for a proposed process using an acid-alcohol leaching technique is presented.
SME Preprint 90-145, 1990, 8 PP.