Richard C Sheridan

US Patent:

41698827, Oct 2, 1979

Filed:

Nov 13, 1978

Appl. No.:

5/959979

Inventors:

Richard C. Sheridan - Sheffield AL

Assignee:

Tennessee Valley Authority - Muscle Shoals AL

International Classification:

C01B 2522

US Classification:

423321R

Abstract:

Impure wet-process phosphoric acid is treated with urea by known processes to produce relatively pure urea phosphate which is then treated with oxalic acid to give solid urea oxalate and purified phosphoric acid product. The urea oxalate is either treated with ammonia to give urea and ammonium oxalate or it is pyrolyzed to produce urea and oxamide.

US Patent:

T9960015, Jul 1, 1980

Filed:

Sep 17, 1979

Appl. No.:

6/076007

Inventors:

Richard C. Sheridan - Sheffield AL
John F. McCullough - Florence AL
Leland L. Frederick - Florence AL

Assignee:

Tennessee Valley Authority - Washington DC

International Classification:

C05B 700

US Classification:

71 36

Abstract:

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 ammonium potassium polyphosphate is dissolved in aqueous ammonia to yield concentrated fertilizer solutions containing the three major nutrients and over 50 percent total plant food. Embodiment No. 2. Phosphoric acid containing 54 to 76 percent P. sub. 2 O. sub. 5 is heated with urea (urea:H. sub. 3 PO. sub. 4 mole ratio 0. 5 to 2. 0) and monopotassium orthophosphate (urea:KH. sub. 2 PO. sub. 4 mole ratio 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.

US Patent:

H6769, Sep 5, 1989

Filed:

Oct 26, 1987

Appl. No.:

7/112784

Inventors:

Richard C. Sheridan - Sheffield AL

Assignee:

Tennessee Valley Authority - Muscle Shoals AL

International Classification:

C07C12701

US Classification:

564 63

Abstract:

A process for producing urea fluorosilicate, [(NH. sub. 2). sub. 2 CO]. sub. 4. multidot. H. sub. 2 SiF. sub. 6, a composition eminently suitable for use as a fungicide in the prevention and control of wheat stem rust. The method involves mixing urea and fluorosilicic acid derived from by-product fluorine in a mole ratio of urea:fluorosilicate acid in the range from about 3. 5:1 to about 4. 5:1 and thereafter dewatering the resulting solution to produce a concentrated solution of urea fluorosilicate. Solid urea fluorosilicate is subsequently obtained by evaporation of the remaining water which is conveniently effected by introducing the resulting solution or melt to concentrator means, or alternatively into a heated, moving bed of preformed granular urea fluorosilicate.

US Patent:

42397391, Dec 16, 1980

Filed:

Nov 6, 1979

Appl. No.:

6/091853

Inventors:

Richard C. Sheridan - Sheffield AL
John F. McCullough - Florence AL

Assignee:

Tennessee Valley Authority - Muscle Shoals AL

International Classification:

C01B 1516

US Classification:

423308

Abstract:

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 melamine is virtually insoluble in concentrated diammonium phosphate solutions; it is filtered from the hot mixture, washed, and recycled to produce more melamine phosphate by reaction with wet-process phosphoric acid. The hot, concentrated diammonium phosphate filtrate is cooled to precipitate purified diammonium phosphate crystals. The product is separated from its mother liquor by filtration, and the resulting filtrate is recycled to the reactor. The small amount of impurities introduced with the melamine phosphate are removed partly with the liberated melamine and partly by centrifugation of the diammonium phosphate solution. The only starting materials for the process are phosphoric acid and ammonia.

US Patent:

40175898, Apr 12, 1977

Filed:

Mar 17, 1976

Appl. No.:

5/667553

Inventors:

John F. McCullough - Florence AL
Richard C. Sheridan - Sheffield AL

Assignee:

Tennessee Valley Authority - Muscle Shoals AL

International Classification:

C01B 1516
C01B 2526

US Classification:

423315

Abstract:

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 short-chain ammonium polyphosphates. The solid product is extracted with water to remove the ammonium polyphosphates and free the insoluble, crystalline melamine for recycle. Thus, the only starting materials consumed in the process are phosphoric acid and ammonia.

US Patent:

43080480, Dec 29, 1981

Filed:

Feb 13, 1980

Appl. No.:

6/121184

Inventors:

Richard C. Sheridan - Sheffield AL
John F. McCullough - Florence AL
Leland L. Frederick - Florence AL

Assignee:

Tennessee Valley Authority - Muscle Shoals AL

International Classification:

C05B 700
C05B 1306

US Classification:

71 36

Abstract:

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 ammonium potassium polyphosphate is dissolved in aqueous ammonia to yield concentrated fertilizer solutions containing the three major nutrients and over 50 percent total plant food. Embodiment No. 2. Phosphoric acid containing 54 to 76 percent P. sub. 2 O. sub. 5 is heated with urea (urea:H. sub. 3 PO. sub. 4 mole ratio 0. 5 to 2. 0) and monopotassium orthophosphate (urea:KH. sub. 2 PO. sub. 4 mole ratio 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.