XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 569
intensity magnetic separation test work were obtained from
previous lab test works. These aforementioned optimized
conditions were particle size k80 index=100 micron, solid
content =30% and drum rotational speed= 1.4 m/s. Table 8
shows the results of the wet medium intensity magnetic
separation.
Wet High Intensity Magnetic Separation (WHIMS)
In addition to wet MIMS separation, wet high intensity
magnetic separation is useful for further hematite iron ore
recovery from the tailing of the wet MIMS. Therefore, the
tailing of wet MIMS was treated in two stages of WHIMS
(rougher and cleaner) to produce a hematite concentrate.
Tailing pulp with around 15% solids was fed through a
centrifugal pump to a pilot scale WHIMS. Background
filed intensities of around 1 T and 0.7 T were applied for
the rougher and cleaner stages, respectively. Final hematite
concentrate was obtained and analyzed for total iron, silica
and alumina content. As shown in table 9around 60% Fe
is achieved in the product in this step at 14.5% mass yield.
As indicated in Table 10 magnetic separation by MIMS
and WHIMS results in a final mixed iron ore concentrate
with 65.53% iron grade, 44.81% yield and also 83.73%
iron content recovery.
CONCLUSIONS
In this paper an innovative technical method called “coarse
pre-concentration followed by wet magnetic separation,”
developed to completely utilize waste rock dump of mag-
netite iron ore mines, was introduced and verified as a fea-
sible solution to reuse iron ore mine wastes as secondary
resources to compensate for the depletion of high-grade
magnetite deposits. While solving the problem of second-
ary storage for the waste rock, his method recovers a large
amount of iron through an uncomplicated, simple and eco-
nomic process. Based on the obtained results, the following
conclusions can be drawn:
• Primary crushing to produce a prticles smaller than
400 mm and then screening at a cut size of 40 mm
was performed and followed by magnetic separation
for the fraction smaller than 40 mm by dry drum
MIMS separator and for the fraction coarser than
40 mm by special belt drum MIMS magnetic sepa-
rator with radial pole arrangement.
Table 7. Chemical analysis of the composite final pre-concentrate
Fe,
%
FeO,
%
TiO
2, %
P
2 O
5, %
SO
3, %
Na
2 O,
%
SiO
2, %
Al
2 O
3, %
CaO,
%
K
2 O,
%
MgO,
%
MnO,
%
35.08 9.13 0.38 0.08 0.25 0.15 10.15 1.5 1.3 0.11 1.05 0.08
Table 8. Wet magnetic separation by MIMS drum separator
Item Yield, %Fe, %FeO, %Fe-rec., %
Feed 100.00 35.07 9.13 100.00
Magnetite concentrate 35.45 67.10 15.5 67.83
Tailing 64.55 17.48 5.63 32.17
Table 9. Wet magnetic separation by WHIMS
Item Yield, %Fe, %FeO, %Fe-rec., %
Feed, Tailing of MIMS 100 17.48 5.63 100.00
Hematite concentrate 14.5 59.60 1.2 49.44
Final tailing 85.5 10.34 2.60 50.56
Table 10. Chemical analysis of the final magnetite concentrate
Fe,
%
FeO,
%
TiO2,
%
P2O5,
%
SO3,
%
Na2O,
%
SiO2,
%
Al2O3,
%
CaO,
%
K2O,
%
MgO,
%
MnO,
%
65.53 12.51 0.09 0.05 0.05 0.08 2.31 0.20 0.4 0.54