US 12,291,450 B2
Pure iron containing compound
Per-Olof Larsson, Helsingborg (SE); Björn Skårman, Höganäs (SE); and Hilmar Vidarsson, Höganäs (SE)
Assigned to HÖGANÄS AB (PUBL), Höganäs (SE)
Appl. No. 17/298,686
Filed by Höganäs AB (Publ), Höganäs (SE)
PCT Filed Dec. 3, 2019, PCT No. PCT/EP2019/083424
§ 371(c)(1), (2) Date Jun. 1, 2021,
PCT Pub. No. WO2020/126456, PCT Pub. Date Jun. 25, 2020.
Claims priority of application No. 18215706 (EP), filed on Dec. 21, 2018.
Prior Publication US 2022/0041449 A1, Feb. 10, 2022
Int. Cl. C01B 25/45 (2006.01); B01D 21/00 (2006.01); B01D 21/26 (2006.01); C01G 49/00 (2006.01)
CPC C01B 25/45 (2013.01) [C01G 49/00 (2013.01); B01D 21/0012 (2013.01); B01D 21/0027 (2013.01); B01D 21/262 (2013.01); C01P 2006/40 (2013.01); C01P 2006/80 (2013.01)] 26 Claims
OG exemplary drawing
 
1. A method of producing an iron containing compound, iron containing precursor, or iron containing aqueous solution comprising the steps of:
providing direct reduced iron produced by direct reduction of iron ore to iron by a reducing gas or elemental carbon;
dissolving the direct reduced iron in a solution comprising at least one organic acid and, optionally, an inorganic acid to provide an iron containing aqueous solution, wherein the pH of the iron containing aqueous solution after dissolution is at most 4.5, and wherein insoluble impurities of the direct reduced iron are maintained in solid form throughout the dissolution process, to obtain an iron containing aqueous solution with suspended insoluble impurities;
separating the said insoluble impurities from the iron containing aqueous solution obtaining a purified iron containing aqueous solution; and
optionally, solidifying said purified iron containing aqueous solution to provide the iron containing compound or iron containing precursor, by drying.