The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 17, 2024
Filed:
Jul. 09, 2020
Yara International Asa, Oslo, NO;
Robertus Louwe, Porsgrunn, NO;
Olav Lier, Porsgrunn, NO;
Yara International ASA, Oslo, NO;
Abstract
A method for crystallizing calcium nitrate from an aqueous calcium nitrate composition including from 6 to 12 weight % nitric acid, from 11 to 17 weight % phosphoric acid, and from 36 to 49 weight % dissolved calcium nitrate, which aqueous composition is optionally directly obtainable from digesting phosphate rock in nitric acid. The method includes filling at least one vertical crystallizing tank through an inlet with the aqueous calcium nitrate composition. The crystallizing tank includes a vertical cylindrical section, a first inlet, a first outlet, a second inlet, three concentric banks of cooling coils, an agitator, and a temperature measurement device. The method includes circulating through the banks of cooling coils a cooling fluid, having an initial temperature ranging from −40° C. to −5° C., and rotating the agitator such that a minimum average heat transfer of 400 W/m·K is achieved on the cooling coil the most distant from the agitator.