US 12,304,876 B2
Method for granulating a melt of an hydrous nitrate mineral salt-based composition, system and use thereof
Per Stokka, Porsgrunn (NO); and Olav Kjøhl
Assigned to YARA INTERNATIONAL ASA, Oslo (NO)
Appl. No. 17/295,143
Filed by YARA INTERNATIONAL ASA, Oslo (NO)
PCT Filed Nov. 22, 2019, PCT No. PCT/EP2019/082188
§ 371(c)(1), (2) Date May 19, 2021,
PCT Pub. No. WO2020/104637, PCT Pub. Date May 28, 2020.
Claims priority of application No. 18207816 (EP), filed on Nov. 22, 2018.
Prior Publication US 2022/0017427 A1, Jan. 20, 2022
Int. Cl. C05C 1/02 (2006.01); B01J 2/00 (2006.01); B01J 2/14 (2006.01); C05C 5/00 (2006.01); C05C 5/04 (2006.01); C05G 5/12 (2020.01)
CPC C05C 1/02 (2013.01) [B01J 2/00 (2013.01); B01J 2/14 (2013.01); C05C 5/005 (2013.01); C05C 5/04 (2013.01); C05G 5/12 (2020.02)] 12 Claims
OG exemplary drawing
 
1. A method for granulating a melt of an hydrous calcium nitrate mineral salt-based composition comprising from 15 to 30 weight % of water, the method comprising the steps of:
a) granulating a melt of the nitrate mineral salt-based composition by a granulator operating according to the agglomeration granulation principle to obtain a set of granules wherein the granulator has an amount of water in a liquid phase;
b) separating out oversized and undersized granules from the granules obtained from step a) to obtain at least a set of oversized granules, a set of undersized granules and a set of granules having a suitable size;
c) crushing the oversized granules obtained from step b);
d) recycling the granules obtained from step c) to the granulator;
e) recycling the undersized granules obtained from step b) to the granulator;
f) during step a) measuring a temperature in the granulator and
g) based on the temperature measured in step f), adjusting the amounts of granules recycled in steps d) and/or e) so as to control the amount of water in the liquid phase and maintain the temperature measured in step f) within a range of 90 to 96° C.
 
11. Uncoated granules having a sieve diameter ranging from 2 mm to 4 mm, comprising an hydrous calcium nitrate mineral salt-based composition, characterized in that they produce less than 1000 mg of dust per kg of granules, determined according to the Yara YTC-LAB-132 fluidization method.