H3PO4 Production Process Utilizing Phosphatic Clay as Feed Material

Waste phosphatic clay presents a difficult disposal problem and a significant loss of P2O5. Recent developments make this study on the use of phosphatic clay as a feed material for H3PO4 production worthwhile. (a) New data from Florida Industrial and Phosphate Research Institute (FIPR) suggest that the “clay” waste can be effectively treated by improved solid separation coupled with flotation to produce feed material for recovering additional phosphate. (b) The use of “OLI Flowsheet” provides capability to predict performance of aqueous-based processes for a range of possible operating conditions. Using the new FIPR data and “OLI Flowsheet” enabled the design of a new process that can potentially extend the usefulness of current P2O5 ore deposits. Predictions using OLI Flowsheet were able to identify process conditions that effectively overcome the difficulty of high Mg content of phosphatic clay. Estimated manufacturing cost in the current study lead to valuation of the P2O5 content of the phosphatic clay recovered/utilized at 60 to 70% of that of the phosphate rock feed material currently used. Phosphatic clay should be considered as a valuable material that is currently given zero value. The new FIPR data and “OLI Flowsheet” enables the design of a new process that can potentially extend the usefulness of current phosphate ore deposits by extending the fraction P2O5 of recovered.