Potassium fluoride stabilized ammonium nitrate and method of producing potassium fluoride stabilized ammonium nitrate

• US 5,098,683 A
• Filed: 03/06/1991
• Issued: 03/24/1992
• Est. Priority Date: 03/06/1991
• Status: Expired due to Fees

• Current Assignee: Prime Technology Incorporated (General Dynamics Corporation)
• Original Assignee: OLIN Corporation
• Inventors: Mehrotra, Ashok K., Markovich, I. Lee
• Primary Examiner(s): Straub, Gary P.
• Assistant Examiner(s): Vanoy, Timothy C.
• Application Number:
  US07/665,628
• Time in Patent Office: 384 Days
• Field of Search: 423/396, 423/266, 23/302 A, 149/46
• US Class Current: 423/266
• CPC Class Codes: C01C 1/18 Nitrates of ammonium
• CPC Class Codes: C06B 31/28 the salt being ammonium nitrate

Abstract

A phase stabilized ammonium nitrate mixed crystal structure is produced by the addition of potassium fluoride. Thus the undesirable abrupt expansion and contraction of ammonium nitrate in the temperature range of use in rocket motor propellants and explosives (-55° C. to λ° C.) is eliminated. The mixture is made by the addition of between about 3% to 5% and preferably about 3.5% by weight potassium fluoride to the ammonium nitrate by a nonhazardous aqueous method.

Claims

1. Crystals comprising a mixture of ammonium nitrate and potassium fluoride wherein the weight percent of potassium fluoride in the mixed crystal is within the range of from about 3.0% to about 5.0%.

2. The crystals according to claim 1 wherein the weight percent of potassium fluoride is between about 3.0% and about 4.0%.

3. The crystals according to claim 2 wherein the weight percent of potassium fluoride is about 3.5%.

4. A method of stabilizing ammonium nitrate which comprises the steps of:

a) heating an aqueous ammonium nitrate solution to less than about 120°

C.;

b) dissolving from 3.0% to about 5.0% by weight potassium fluoride in the aqueous solution;

c) cooling the aqueous solution of potassium fluoride and ammonium nitrate to less than about 80°

C.; and

d) maintaining the temperature of the solution at about 77°

C. until the water has evaporated leaving behind solid crystals of stabilized ammonium nitrate.

5. The method according to claim 4 which is accomplished by heating the aqueous ammonium nitrate solution to about 110°

C.

6. The method according to claim 4 which is accomplished by dissolving from 3.0% to about 4.0% by weight potassium fluoride in the aqueous solution.

7. The method according to claim 6 which is accomplished by dissolving about 3.5% by weight potassium fluoride in the aqueous solution.

8. The method according to claim 7 which is accomplished by dissolving about 3.5% by weight potassium fluoride in the aqueous solution at about 110°

C.