Phosphate Engineering and Construction Company

Other

Advanced Separation Technologies Inc.

American Petro Mart, Inc.

Potash Corporation of Saskatchewan

William R Erickson

James D Wilson

Leif E Bouffard

W Wes Berry

Solon G Whitney

Gary D Derdall

Robin L Phinney

Donald B Stain

High purity silica is obtained by the reaction of impure by-product waste silica with hydrogen fluoride preferably in the presence of water or sulfuric acid, producing silicon tetrafluoride gas and a mother liquor. The silicon tetrafluoride is separated from the mother liquor, which retains the impurities originally contained within the impure silica. The silicon tetrafluoride gas is contacted with high-purity water, in a clean environment, to form a slurry of high purity silica and high-purity hydrofluosilicic acid (FSA). A portion of the silica is filtered from the slurry and washed producing a high purity silica product. The rest of the silica-FSA slurry is preferably reacted with ammonia to form a slurry of ammonium fluoride and silica. The silica is separated from the ammonium fluoride and preferably washed and calcined to remove any remaining ammonium fluoride, leaving additional high purity silica product. The separated ammonium fluoride may be reacted with lime to produce additional products for recycling back into the process. The process can be repeated for further purification of the silica. The process may be used to produce substantially spherical silica particles about 1.0 to about 25.0 microns in diameter.

Process for the production of high purity silica from waste by-product

Fluosilicic acid is reacted with phosphate rock in order to produce wet process phosphoric acid and calcium fluoride which is later reacted with sulfuric acid to produce hydrogen fluoride and calcium sulfate. The hydrogen fluoride is then stripped from the phosphoric acid and recovered as either anhydrous hydrogen fluoride or concentrated hydrofluoric acid or reacted with aluminum trihydrate to produce aluminum fluoride; with sodium carbonate to produce sodium fluoride/bifluoride; or with ammonia to produce ammonium fluoride/bifluoride.

Process for the production of phosphoric acid and calcium fluoride

Process for the production of phosphoric acid and hydrogen fluoride from

Fluosilicic acid is reacted with phosphate rock in order to produce wet process phosphoric acid and calcium fluoride which is later reacted with sulfuric acid to produce hydrogen fluoride and calcium sulfate. The hydrogen fluoride is then stripped from the phosphoric acid and recovered as either anhydrous hydrogen fluoride or concentrated hydrofluoric acid or reacted aluminum trihydrate to produce aluminum fluoride; with sodium carbonate to produce sodium fluoride/bifluoride; or with ammonia to produce ammonium fluoride/bifluoride.

A cap to be placed over the spout of a faucet and form a tight watertight connection therebetween. Located through the cap is a through hole through which a shackle of the padlock is to be located with this shackle to interfere with the exterior threaded connection on the spout and prevent disengagement of the cap from the faucet. With this cap installed on the spout of the faucet, flow of water through the faucet is prevented.

Faucet locking apparatus

An apparatus for producing phosphoric acid by the recovery of P.sub.2 O.sub.5 from a phosphate ore is disclosed. A slurry of a phosphate ore in an aqueous phosphoric acid solution is formed in each of a plurality of reaction zones connected in series. Phosphate ore is introduced into the first reaction zone and phosphoric acid into the last reaction zone whereby the reaction of the phosphoric acid with the ore forms a slurry of coarse solids, fine solids and monocalcium phosphate in the phosphoric acid solution. A first process stream comprising coarse solids is removed from the first reaction zone and each of the other reaction zones and is tranferred to the adjacent, successive reaction zone. A second process stream comprising fine solids is removed from the last reaction zone and the other reaction zones and is transferred into the adjacent, preceding zone in a direction which is countercurrent to the direction of flow of the first process stream and is concurrent with the direction of flow of the phosphoric acid from the last to the first reaction zones. A differential of phosphoric acid concentration is maintained between the reaction zones with the concentration decreasing in each reaction zone in the direction of flow of the first process stream.

Apparatus for producing phosphoric acid from phosphate ore

Relatively pure monopotassium phosphate is produced from wet process phosphoric acid in a process wherein the phosphoric acid is mixed with potassium chloride and recycled components from downstream product and by-product recovery steps and heated to permit hydrogen and chloride to evolve from the melt as gases and wherein the melt is subsequently treated so as to remove impurities so that the monopotassium phosphate may be recovered as a relatively pure crystalline product with low chloride content.

Production of monobasic potassium phosphate with low chloride content

A process and apparatus for producing phosphoric acid by the recovery of P.sub.2 O.sub.5 from a phosphate ore is disclosed. A slurry of a phosphate ore in an aqueous phosphoric acid solution is formed in each of a plurality of reaction zones connected in series. Phosphate ore is introduced into the first reaction zone and phosphoric acid into the last reaction zone whereby the reaction of the phosphoric acid with the ore forms a slurry of coarse solids, fine solids and monocalcium phosphate in the phosphoric acid solution. A first process stream comprising coarse solids is removed from the first reaction zone and each of the other reaction zones and is transferred to the adjacent, successive reaction zone. A second process stream comprising fine solids is removed from the last reaction zone and the other reaction zones and is transferred into the adjacent, preceding zone in a direction which is countercurrent to the direction of flow of the first process stream and is concurrent with the direction of flow of the phosphoric acid from the last to the first reaction zones. A differential of phosphoric acid concentration is maintained between the reaction zones with the concentration decreasing in each reaction zone in the direction of flow of the first process stream.

Method for producing phosphoric acid from phosphate ore

A process for producing potassium phosphates by ion exchange using an Advanced Separation Device (ASD) is disclosed. The process is carried out by supplying a phosphate salt solution, a washing solution and a potassium salt regeneration solution to respective fixed feed ports in periodic fluid communication with a plurality of resin-filled chambers moving about a circular path. Passage of the phosphate salt solution through potassium loaded resin forms potassium phosphates and cation loaded resin by ion exchange. After washing out residual salts, the cation loaded resin is regenerated by adding a potassium salt which loads the resin with potassium and strips it of the cation in the form of a soluble cation salt. By virtue of the ASD, potassium phosphate may be produced continuously and with greater efficiency than is possible with conventional ion exchange processes since the potassium salt and phosphate salt feed solutions may be fortified in an intra-stage fashion, i.e. during the course of the ion exchange or regeneration stages. In similar fashion, the pH may be adjusted in an intra-stage fashion.

Production of potassium phosphates by ion exchange

A process is disclosed for the continuous removal of ammonia from wastewater which converts the otherwise undesirable ammonia to a commercially useful end product such as ammonium phosphate. The process is carried out in an Advanced Separation Device which comprises a plurality of chambers moving about a circular path in periodic fluid communication with a plurality of fixed feed and discharge ports. The chambers are filled with a zeolite adsorbent which effectively adsorbs the ammonium ions contained in the wastewater at low pH levels but which, when contacted with an alkaline regeneration solution, releases the previously adsorbed ammonium in the form of ammonia gas, for which the zeolite has no affinity. By virtue of the ASD design, it is possible to add acidic materials to the wastewater in an intra-stage fashion i.e. during the adsorption step so as to optimize process efficiency. Similarly, intra-stage addition of alkaline materials during the regeneration step results in increased process efficiency. The process may be practiced with both industrial and municipal wastewaters.

Removal of ammonia from wastewater

Adjustably metered transfer of resin increments in folded bed ion exchange systems are provided by a method and apparatus in which compacted liquid-containing resin granules are expelled from a column into a metering chamber which is filled to a level of a granule-retaining screen, the cut-off of the granule filling being signaled by liquid moving through the screen to a control level thereabove and/or by an increase in the hydraulic pressure of the liquid below the screen. In preferred embodiments the measuring chamber is provided with a flexible wall which is positioned to either increase or decrease the volume of the measuring chamber and thereby selectively vary the volume of the granule increment captivated by the chamber. The invention provides for the pulsing of resin increments of precisely and adjustably metered volume, and provides a means for keeping the loading and regeneration sides of the system in resin transfer balance.

Adjustably metered transfer of resin increments in folded bed ion

Adsorbed calcium is selectively removed from cation exchange resins in the presence of adsorbed magnesium by eluting the resin with aqueous sulfuric acid saturated with CaSO.sub.4 and undersaturated with MgSO.sub.4 to obtain a solution supersaturated with CaSO.sub.4 from which the CaSO.sub.4 can be readily precipitated. The magnesium is subsequently removed from the resin by eluting with aqueous sulfuric acid, such as 20-70% H.sub.2 SO.sub.4. The method is advantageously used in the regeneration of cation exchange resins, such as the loaded resins used for treatment of phosphate rock-derived phosphoric acid.

Growing community of inventors

Lakeland, FL, United States of America

William R Erickson