Removal of cationic impurities from inorganic solutions
AssigneePhosphate Engineering & Construction Co., Inc.
InventorSusan B. Morris
Life of this patent
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Abstract
A process for the removal of cationic impurities from inorganic solutions and especially wet process phosphoric acid solutions wherein the solutions are passed through an ammonium ion or hydrogen ion charged cation exchange resin to remove various metal cations and thereafter the ion exchange resin is regenerated using an excess volume of ammonium sulfate solution which is subsequently treated to precipitate and filter out the cationic impurities so that the ammonium sulfate solution may be recycled for further ion exchange regeneration.
Claims16
A method for removing cationic impurities from inorganic feed solutions comprising the steps of passing the feed solution through an ion exchanger having an ion exchange resin charged with a cation selected from the group consisting of ammonium ions and hydrogen ions in order to remove the cationic impurities from the feed solution, regenerating the ion exchange resin within the ion exchanger by passing a saturated ammonium sulfate regenerant solution therethrough and recovering a dilute regenerant solution, resaturating the dilute regenerant solution passing from the ion exchanger to thereby precipitate impurities therefrom as sulfate salts and recovering a resaturated ammonium sulfate solution.
A method for removing cationic impurities from a wet process phosphoric acid solution comprising the steps of:
- (a) passing the wet process phosphoric acid solution through an ion exchanger having an ion exchange resin charged with cations selected from the group of ammonium ions and hydrogen ions, in order to remove the cationic impurities from the solution;
- (b) regenerating the ion exchange resin by passing first and second portions of a saturated ammonium sulfate regenerant solution therethrough in which a total of 4-10 bed volumes of saturated ammonium sulfate solution are used to regenerate the ion exchange resin;
- (c) filtering the first portion of regenerant solution passing from the ion exchanger to remove solids therefrom;
- (d) adding NH.sub.3 to the first portion of regenerant solution to form metallic hydroxides;
- (e) filtering the metallic hydroxides from the first portion of regenerant solution;
- (f) thereafter combining the second portion of regenerant solution passing from the ion exchanger with the first portion regenerant solution and adding substantially pure sulfuric acid thereto to obtain a resaturated ammonium sulfate regenerant solution;
- and
- (g) subsequently recycling the resaturated ammonium sulfate regenerant solution to the ion exchanger.
A method for removing cationic impurities from a wet process phosphoric acid solution comprising the steps of
- (a) passing the solution through an ion exchanger having an ion exchange resin charged with cations selected from the group of ammonium ions and hydrogen ions, in order to remove the cationic impurities from the solution;
- (b) regenerating the exchange resin by passing a saturated ammonium sulfate regenerant solution therethrough in which 4-10 bed volumes of saturated ammonium sulfate regenerant solution are used to regenerate the ion exchange resin;
- (c) resaturating the regenerant solution passing from the ion exchanger by adding NH.sub.3 and (NH.sub.4)2SO.sub.4 to obtain a resaturated ammonium regenerant solution, and filtering;
- (d) subsequently recycling the resaturated ammonium regenerant solution to the ion exchanger.
Dependencies are inferred from the claim text.