Recovery of fluorine, uranium and rare earth metal values from phosphoric acid by-product brine raffinate
AssigneeAllied Chemical Corporation
InventorsChristian A. Wamser, Charles P. Bruen
Life of this patent
Estimating the term…
Abstract
A method for recovering substantially all of the fluorine and uranium values and at least 90 percent of the rare earth metal values from brine raffinate obtained as by-product in the production of phosphoric acid by the hydrochloric acid decomposition of tricalcium phosphate minerals. A basically reacting compound is added to the brine raffinate to effect a pH of at least about 9, whereby fluorine, uranium and rare earth metal values are simultaneously precipitated therefrom. These values may then be separately recovered from the precipitate by known processes.
Claims9
A process for simultaneous recovery of fluorine, uranium and rare earth metal values from a tricalcium phosphate mineral containing same, which comprises:
- a. contacting said mineral with hydrochloric acid to digest said mineral, thereby forming (1) a digest solution containing phosphoric acid, calcium chloride, fluorine, uranium and rare earth metal values and (2) an insoluble residue;
- b. separating said insoluble residue from said digest solution;
- c. contacting said separated digest solution with an organic solvent capable of dissolving phosphoric acid but having limited miscibility with water free of phosphoric acid, thereby forming an organic phase containing phosphoric acid and an aqueous phase containing calcium chloride and fluorine, uranium and rare earth metal values;
- d. separating said organic phase from said aqueous phase;
- e. admixing said separated aqueous phase with an amount of a basically reacting compound sufficient to effect a pH of at least about 9, thereby forming:
- 1. a basic solution containing calcium chloride and
- 2. precipitated solids containing fluorine, uranium and rare earth metal values;
- and
- f. separating the precipitated solids containing fluorine, uranium and rare earth metal values from said basic solution.
Dependencies are inferred from the claim text.