Patent ID: 10689732

Abstract:
A method of controlling iron in a hydrometallurgical process is disclosed. The method may comprise the steps of: leaching (14, 114) a feed slurry (2, 102); forming a pregnant leach solution (12a, 12b; 112a, 112b); removing a first leach residue (18, 118) from the pregnant leach solution (12a, 12b); and sending a portion (12b, 112b) of the pregnant leach solution (12a, 12b) and/or raffinate (22, 122) produced therefrom, to an iron removal process (34, 134). According to some preferred embodiments, the iron removal process (34, 134) may comprise the steps of: sequentially processing the pregnant leach solution (12a, 12b) and/or raffinate (22, 122) produced therefrom in a first reactor (R1) a second reactor (R2), and a third reactor (R3); maintaining a pH level of the first reactor (R1) above 4, by virtue of the addition of a first base; maintaining a pH level of the second (R2) and/or third (R3) reactors above 8.5, by virtue of a second base; and forming solids (46) comprising magnetite (68). The method may further comprise the steps of performing a solid liquid separation step (36) after the iron removal process (34, 134); and performing a magnetic separation step (64) to remove magnetite (68) from said solids comprising magnetite (68), without limitation. A system for performing the method is also disclosed.