| Patent Number |
Title Of Patent |
Date Issued |
| T996001 |
Production of ammonium potassium polyphosphates |
July 1, 1980 |
| Embodiment No. 1. Urea phosphate prepared from wet-process phosphoric acid is heated with monopotassium orthophosphate in a mole ratio of 0.25 to 4.0 at 130.degree. to 200.degree. C. to form an ammonium potassium polyphosphate having an average chain length between 1.2 and 2.5. The a |
| T988006 |
Chemical beneficiation of phosphatic limestone and phosphate rock with .alpha.-hydroxysulfonic a |
November 6, 1979 |
| A method of selectively extracting calcite and dolomite away from apatite in phosphate rock or phosphatic limestone wherein the phosphate rock or phosphatic limestone is treated with a mixture of sulfur dioxide, water, and a carbonyl compound. Solids are separated from the liquid phase. |
| T973004 |
Production of urea-ammonium polyphosphates from urea phosphate |
August 1, 1978 |
| a process for the production of high-purity urea-ammonium polyphosphate fertilizers from crystalline urea orthophosphate derived from the reaction of wet-process acid and urea. Initially, urea phosphate was pyrolyzed in one stage to give molten urea-ammonium polyphosphates that contained |
| T970008 |
Removal and recovery of sulfur oxides from gas streams with melamine |
May 2, 1978 |
| a process for the removal and recovery of sulfur oxides from gas streams by contacting the gas stream with an aqueous suspension of melamine containing an oxidation inhibitor such as para-phenylenediamine whereupon a mixture of solid, hydrated melamine sulfites and solid, hydrated me |
| T970007 |
Uranium recovery from wet-process phosphoric acid |
May 2, 1978 |
| a method of recovering uranium from wet-process phosphoric acid wherein the acid is treated with a mixture of an ammonium salt or ammonia, a metallic reducing agent such as iron, aluminum or zinc, and then a miscible solvent such as methanol. The precipitated solids, which are separated |
| T962001 |
Preparation of dicalcium phosphate from phosphate rock by the use of sulfur dioxide, water, and |
September 6, 1977 |
| dicalcium phosphate is prepared from phosphate rock by a process which comprises reacting phosphate rock with sulfur dioxide and an organic carbonyl compound for 0.5 to 10 hours while maintaining the temperature of the reaction mixture below 50.degree. C. The reaction yields a mixture of |
| 4308048 |
Production of ammonium potassium polyphosphates |
December 29, 1981 |
| Embodiment No. 1. Urea phosphate prepared from wet-process phosphoric acid is heated with monopotassium orthophosphate in a mole ratio of 0.25 to 4.0 at 130.degree. to 200.degree. C. to form an ammonium potassium polyphosphate having an average chain length between 1.2 and 2.5. The a |
| 4239739 |
Manufacture of purified diammonium phosphate |
December 16, 1980 |
| Purified diammonium phosphate is produced by neutralizing relatively pure melamine orthophosphate, prepared from wet-process phosphoric acid, with ammonia in a hot solution of diammonium phosphate to give a slurry of melamine in concentrated diammonium phosphate solution. The liberated |
| 4238459 |
Chemical beneficiation of phosphatic limestone and phosphate rock with .alpha.-hydroxysulfonic a |
December 9, 1980 |
| A method of selectively extracting calcite and dolomite away from apatite in phosphate rock or phosphatic limestone wherein the phosphate rock or phosphatic limestone is treated with a mixture of sulfur dioxide, water, and a carbonyl compound. Solids are separated from the liquid phase. |
| 4236911 |
Purification and conversion of phosphoric acid to ammonium phosphates |
December 2, 1980 |
| A method of purifying filter-grade wet-process phosphoric acid, then converting the purified phosphoric acid directly to ammonium phosphate without first concentrating the phosphoric acid. The wet-process phosphoric acid is treated with a mixture of ammonia or an ammonium salt and ac |
| 4217128 |
Production of urea-ammonium polyphosphates from urea phosphate |
August 12, 1980 |
| Crystalline urea phosphate is pyrolyzed in one stage to give molten urea ammonium polyphosphates that contains up to 95 percent of the phosphate as polyphosphate. These are then processed into high-analysis solid or liquid fertilizers. Addition of urea to the process to maintain a urea:b |
| 4180545 |
Uranium recovery from wet-process phosphoric acid |
December 25, 1979 |
| A method of recovering uranium from wet-process phosphoric acid wherein the acid is treated with a mixture of an ammonium salt or ammonia, a reducing agent, and then a miscible solvent. Solids are separated from the phosphoric acid liquid phase. The solid consists of a mixture of metal |
| 4139597 |
Removal and recovery of sulfur oxides from gas streams with melamine |
February 13, 1979 |
| A process for the removal and recovery of sulfur oxides from gas streams by contacting the gas stream with an aqueous suspension of melamine whereupon a mixture of solid, hydrated melamine sulfites, hydrated melamine sulfate is formed. The solids are separated from the reaction product a |
| 4113842 |
Preparation of dicalcium phosphate from phosphate rock by the use of sulfur dioxide, water, and |
September 12, 1978 |
| A method of preparing dicalcium phosphate from phosphate rock wherein the rock is treated with a mixture of water, carbonyl, and sulfur dioxide. Solids are separated from the liquid phase. The solid phase consists of a mixture of gangue, and calcium .alpha.-hydroxysulfonate. Carbonyl and |
| 4017589 |
Production of ammonium polyphosphates from melamine phosphates |
April 12, 1977 |
| Ammonium polyphosphates are prepared by a process which comprises heating melamine orthophosphate prepared from impure wet-process phosphoric acid in a stream of gaseous ammonia at a temperature between 150.degree. C and 210.degree. C to produce a mixture of melamine and relatively pure |
| 3975178 |
Purification of wet-process phosphoric acid with methanol and ammonia |
August 17, 1976 |
| Our invention relates to an improved process for the partial purification of wet-process phosphoric acid with co-production of impure phosphoric acid or solid fertilizer materials containing most of the impurities originally present in the crude acid. The crude acid is treated with m |
| 3967948 |
Purification of phosphoric acid with urea and nitric acid |
July 6, 1976 |
| My invention relates to a new method for purification of wet-process phosphoric acid with co-production of nitrogen solution. The crude acid is treated with urea by known processes to form urea phosphate free of most of the impurities in the crude acid. The urea phosphate is treated with |
