PROCESS FOR GRANULATING X-O-O AND X-O-Y GRADES OF FERTILIZER

• US 3,619,160 A
• Filed: 06/17/1968
• Issued: 11/09/1971
• Est. Priority Date: 06/17/1968
• Status: Expired due to Term

• Current Assignee: James E. Gabrielson, Leonard Berkowitz
• Original Assignee: James E. Gabrielson, Leonard Berkowitz
• Inventors: Gabrielson, James E., Berkowitz, Leonard
• Primary Examiner(s): Friedman, Reuben
• Assistant Examiner(s): Hart, Charles N.
• Application Number:
  US04/737,595
• Time in Patent Office: 1,240 Days
• Field of Search: 71/28,59,60,61,63,64DA,64DB,30 23/119
• US Class Current: 71/30
• CPC Class Codes: C05C 1/02 Granulation apparatus B01J2/00; Pelletisation; Stabilisation; Colouring
• CPC Class Codes: C05C 3/005 Post-treatment
• CPC Class Codes: C05C 9/005 Post-treatment
• CPC Class Codes: C05D 1/005 post-treatment

Abstract

X-O-O grades of fertilizer (fertilizer containing substantially only nitrogen) normally consisting essentially of diammonium sulfate and X-O-Y grades of fertilizer (fertilizer containing nitrogen and potassium) composed essentially of diammonium sulfate and potassium chloride can be effectively granulated to a desirable commercial size in the presence of a small amount (5-12 wt. percent) of a urea or ammonium nitrate additive while maintaining the temperature in the granulator of between about 150* to 210* F.

Claims

2. A process according to claim 1 wherein X ranges from 10 to 20 and Y ranges from 9 to 30 to produce a granulated fertilizer containing 33 to 77 weight percent (NH4)2SO4, 15 to 50 weight percent KCL and 5 to 12 weight percent additive.

3. A process according to claim 1 wherein R ranges from 2 to 4.

4. A process according to claim 1 for the production of X-O-Y grade fertilizer wherein X ranges from 14 to 16 and Y ranges from 16 to 21 to produce a granulated fertilizer containing from 52 to 64 weight percent (NH4)2SO4, 28 to 36 weight percent KCL and 8 to 10 weight percent additive.

5. A process according to claim 1 for the continuous production of an X-O-O grade of fertilizer, wherein X ranges from 22 to 24 to produce a granulated fertilizer containing from 88 to 95 weight percent diammonium sulfate and 5 to 12 weight percent additive.

6. A process according to claim 4 wherein R ranges from 2 to 4.

7. A process according to claim 6 wherein from 8 to 10 weight percent urea is employed as the additive.

8. In a process for the continuous production of X-O-Y grades of granulated fertilizer wherein X ranges from 14 to 16 and Y ranges from 16 to 21 which comprises adding a slurry composed of about 34 to 50 weight percent water and 50 to 64 weight percent (NH4)2SO4 and a solid feed composed essentially of 70 to 80 weight percent KCl into the upper end of an inclined rotating drum;

therein maintaining a bed of discrete rolling particles of (NH4)2SO4 and KCl;

withdrawing said particle materials from the lower end of said drum;

introducing said withdrawn material into a dryer;

passing the dried Material into a sizing means equipped with a 6-mesh Tyler screen and a 20-mesh Tyler screen, recovering the material retained on the 20-mesh Tyler screen as the desired size granulated fertilizer product;

recycling the material which passes through the 20-mesh Tyler screen to the drum and recycling the material which does not pass through the 6-mesh Tyler screen to a crushing means and thereafter reintroducing the material into the sizing means;

the improvement which comprises granulating said compositions in said drum in the presence of 5 to 12 weight percent based on total starting reagents of an additive selected from the group consisting of urea and NH4NO3 at a granulation temperature of from about 170* to 200* F. such that at least 1/1+R of the material withdrawn from the drum, where R is the ratio of undersize granulated particles recycled to the amount of desired size granulated fertilizer product actually formed, is retained on the 20-mesh Tyler screen as the desired size granulated fertilizer product.

9. The process of claim 8 wherein R ranges from 2 to 4.

10. The process of claim 9 wherein the slurry is formed by ammoniating sulfuric acid having a concentration of from 90 to 95 percent H2SO4 in a preneutralizer vessel to form a slurry of a diammonium sulfate therein.

11. The process of claim 10 wherein the additive is urea.