US 11,912,634 B2
Calcium sulfate urea granules and methods for producing and using the same
Andrew George Kells, Wilton (GB); and Mohamed Akasha M. Khaleel, Riyadh (SA)
Assigned to SABIC Global Technologies B.V., Bergen op Zoom (NL)
Filed by SABIC Global Technologies B.V., Bergen op Zoom (NL)
Filed on May 11, 2022, as Appl. No. 17/741,638.
Application 17/741,638 is a continuation of application No. 16/631,278, granted, now 11,352,306, previously published as PCT/IB2018/055399, filed on Jul. 19, 2018.
Claims priority of provisional application 62/626,932, filed on Feb. 6, 2018.
Claims priority of application No. 201711026033 (IN), filed on Jul. 21, 2017.
Prior Publication US 2022/0267230 A1, Aug. 25, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. C05G 5/12 (2020.01); C05G 5/30 (2020.01); C05C 9/00 (2006.01); C05D 3/00 (2006.01)
CPC C05G 5/12 (2020.02) [C05C 9/005 (2013.01); C05D 3/00 (2013.01); C05G 5/30 (2020.02); C05G 5/36 (2020.02)] 20 Claims
OG exemplary drawing
 
1. A calcium sulfate urea (UCS) fertilizer granule comprising urea, calcium sulfate, and a calcium sulfate urea adduct, wherein the granule comprises 33 wt. % to 40 wt. % elemental nitrogen, 2 wt. % to 5 wt. % elemental calcium, 2 wt. % to 5 wt. % elemental sulfur, 0.1 wt. % to 50 wt. % ammonium sulfate, and less than 1 wt. % free moisture, wherein at least 30 wt. % of the urea in the granule is comprised in the calcium sulfate urea adduct.
 
10. A fertilizer blend or compounded fertilizer comprising the UCS fertilizer granule of claim 1, and at least one additional component.
 
14. A method of making the calcium sulfate urea (UCS) fertilizer granule of claim 1, the method comprising:
combining urea, calcium sulfate, and water to form an aqueous slurry, wherein urea is combined in excess of the stoichiometric ratio for production of a calcium sulfate urea adduct and the urea and calcium sulfate are combined in sufficient ratios to produce the aqueous slurry capable of producing a dried product containing 33 wt. % to 40 wt. % elemental nitrogen, 2 wt. % to 5 wt. % elemental calcium, 2 wt. % to 5 wt. % elemental sulfur;
mixing the aqueous slurry under conditions sufficient to produce a calcium sulfate urea adduct wherein at least 30 wt. % of the urea in the granule is comprised in the calcium sulfate urea adduct; and
removing at least a portion of the water from the aqueous slurry to form the calcium sulfate urea (UCS) fertilizer granule with less than 1 wt. % free moisture.
 
20. A calcium sulfate urea (UCS) slurry comprising 12 to 16% water, urea, calcium sulfate, a calcium sulfate urea adduct, and ammonium sulfate in amounts such that when the slurry is dried, the dried slurry comprises 33 wt. % to 40 wt. % elemental nitrogen, 2 wt. % to 5 wt. % elemental calcium, and 2 wt. % to 5 wt. % elemental sulfur.