Granted Patent B2

US 12,319,632 · App. 18/472,794 · Granted Jun 3, 2025

Inventors: Harri Tapio Kiiski (Riyadh, SA); Andrew George Kells (Riyadh, SA); Mohamed Akasha M. Khaleel (Riyadh, SA); Nilkamal Bag (Bangalore, IN)

Assignee: SABIC AGRI-NUTRIENTS COMPANY

C05G5/12C05C9/005C05D3/00C05G5/30C05G5/36

Abstract

Claims (18)

1. A calcium sulfate urea (UCS) fertilizer granule comprising urea, calcium sulfate, and a calcium sulfate urea adduct, wherein 50 wt. % to 80 wt. % of the urea in the granule is comprised in the calcium sulfate urea adduct, and wherein the granule comprises 32.5 to 44 wt. % elemental nitrogen, 4.5 to 15 wt. % elemental calcium, and 4 to 12 wt. % elemental sulfur.

2. The UCS fertilizer granule of claim 1 , wherein the composition comprises a urease inhibitor, a nitrification inhibitor, magnesium, zinc, and/or boron.

3. The UCS fertilizer granule of claim 2 , wherein the composition comprises both zinc and boron.

4. The UCS fertilizer granule of claim 2 , wherein the composition comprises both a urease inhibitor and magnesium.

5. The UCS fertilizer granule of claim 1 , wherein a portion of the surface of the calcium sulfate urea adduct includes a layer comprising urea, calcium sulfate, or calcium sulfate urea adduct, or any combination or all thereof.

6. The UCS fertilizer granule of claim 1 , wherein the composition comprises 32.5 wt. % to 33.5 wt. % elemental nitrogen, 4.5 wt. % to 5.5 wt. % elemental calcium, 4 wt. % to 5.5 wt. % elemental sulfur.

7. The UCS fertilizer granule of claim 1 , wherein the adduct is CaSO 4 ·4CO(NH) 2 .

8. The UCS fertilizer granule of claim 1 , wherein the granule comprises calcium sulfate urea adduct particles, urea particles, and calcium sulfate particles.

9. A method of fertilizing, the method comprising applying a plurality of calcium sulfate urea granules of claim 1 to a portion of the soil, a crop, or the soil and the crop.

10. The method of claim 9 , wherein soil is submerged under water and the granules sink in the water to contact the soil.

11. A process to prepare a calcium sulfate urea fertilizer granule comprising a calcium sulfate urea adduct, the process comprising:

(a) combining urea, hydrated and/or anhydrous calcium sulfate, and steam and/or water under conditions sufficient to form an aqueous solution comprising water, urea, and calcium sulfate, wherein the urea is solubilized in the aqueous solution;

(b) mixing the aqueous solution under conditions sufficient to produce a wet fertilizer granule comprising a calcium sulfate urea adduct and water; and

(c) removing at least a portion of the water from the wet fertilizer granule to form the calcium sulfate urea granule,

wherein the conditions in (a) comprise a temperature of 85° C. to 120° C.

12. The process of claim 11 , wherein the wet fertilizer granule in step (b) includes a sufficient amount of water such that the composition is formable.

13. The process of claim 11 , wherein step (c) comprises a temperature of 80° C. up to 100° C.

14. The process of claim 11 , wherein at least 30% of the urea from step (a) is converted to the calcium sulfate urea adduct.

Assignments (3)

Priority Claims (1)

Continuity (4)

References Cited (136)