Page 21 - Mines and Minerals Reporter eMagazine - Volume December 2024

IRON ORE MINING

contained hematite [50 %], quartz [8 %], clay [2 %], goethite No. Characteristics Data
[35 %], martite [5 %], magnetite, apatite, chlorite, pyrite[Tr]. 1 SSPL Plant, Hospet [7]
The DAT produced a concentrate assaying [62 % Fe, 6.02
% SiO2, 0.85 % FeO, 0.82 % Al2O3, 0.03 % P, 0.03 % S, 2.20 2 Physical Brown grey coloured fines
% LOI with 85 % Fe recovery at 80 wt% yield indicating the 55.24 % Fe, 5.61 % SiO2, 0.70 % FeO,
easy amenability of sample to gravity/WHIMS. The process 3 Chemical 8.81 % Al2O3, 0.05 % P, 0.03 % S, 5.60
% LOI
comprised of stage grinding to -0.1 mm, desliming to remove
Hematite [60 %], quartz [Tr], gibbsite [5
10 lm slims, gravity–WHIMS of gravity tails which yielded a %], ferruginous clay [15 %], goethite [20
concentrate assaying [64 % Fe, 3.92 % SiO2, 0.52 % Al2O3, 1.05 4 Mineralogy %], martite, magnetite, apatite, chlorite,
% FeO, 0.03 % P, 0.03 % S, 2.42 % LOI with 83 % Fe recovery at pyrite[Tr]
78 wt% yield meeting the pellet grade. The results are given DAT: deslime, sink float
in Table 4. The grade was low at MOG coarser than 0.2 mm 5 [3SG], iso-dynamic ~60 % Fe concentrate with 40 % Fe
due to interlocking and Fe recovery was low for size finer than mag separation of recovery at 37 wt% yield
sinks at -0.25 mm
0.074 mm due to slime constraints on gravity and WLIMS
process. Incidentally similar results were obtained by IBM Process: stage crush >62 % Fe, 2.92 % SiO2, 0.75 % FeO, 4.52
% Al2O3, 0.03 % P, 0.03 % S, 2.42 % LOI
while treating ores from the same belt. to -1 mm, attrition concentrate with 56 % Fe recovery at
6 scrubbing, deslime, 50 wt% yield. Optional process reduced
[optional gravity–
WHIMS of sands]. SiO2 and Al2O3 by 1.5 %, but reduced the
Fe distribution and yield by 15–10 %
Table 5 Soft friable clayey iron ore fines

SOFT FRIABLE CLAYEY IRON ORE FINES
FROM HOSPET, KARNATAKA

The brownish dark grey coloured Soft friable clayey iron ore
fines from Hospet, Karnataka assayed 55.24 % Fe, 5.61 %
SiO2, 0.70 % FeO, 8.81 % Al2O3, 0.05 % P, 0.03 % S, 5.60 % LOI
and contained hematite [60 %], quartz[Tr], gibbsite [5 %],
ferruginous clay [15 %], goethite [20 %], martite, magnetite,
Fig. 3 Typical ferruginous quartzite–fine grained BHQ. The polished lump apatite, chlorite, pyrite[Tr]. The DAT yielded a concentrate
showing the intergrowth of hematite and quartz, reflected light, 910 assaying *60 % Fe concentrate with 40 % Fe recovery at 37
magnification
wt% yield.

The results are given in Table 5. Figure 1 shows the intimate
No. Characteristics Data association of clay with iron minerals. The sample is amenable
M/s MEPL, M S Mines, to simple attrition and washing yielding only sinter grade
1 [7]
Chitradurga concentrates. The process comprises of a stage crush to -1
2 Physical Black grey coloured fines mm, attrition scrubbing, desliming yielding a concentrate
59.60 % Fe, 9.06 % SiO2, 1.06 assaying *62 % Fe, 2.92 % SiO2, 0.75 % FeO, 4.52 % Al2O3,
3 Chemical % FeO, 1.09 % Al2O3, 0.05 % 0.03 % P, 0.03 % S and 2.42 % LOI with 56 % Fe recovery at 50
P, 0.03 % S, 4.02 % LOI wt% yield. Incidentally IBM [2] evolved a process comprising
Hematite [50 %], quartz [8 of stage crushing to -1 mm, attrition scrubbing, desliming,
%], clay [2 %], goethite [35
4 Mineralogy gravity concentration and WHIMS of gravity tails–slimes
%], martite [5 %], magnetite,
apatite, chlorite, pyrite[Tr] yielded a sinter grade concentrate assaying[63.5 % Fe with Fe
>62 % Fe, 6.02 % SiO2, 0.85 distribution of 50 % and wt% yield of 35 from highly clayey
DAT: deslime, sink float [3SG], % FeO, 0.82 % Al2O3, 0.03 and slimy low grade ores from Hospet.
5 iso-dynamic mag separation of % P, 0.03 % S, 2.20 % LOI
sinks at -0.25 mm concentrate with 85 % Fe Lateritic Lumpy Hydrated Iron Oxide Lumpy Ore from CN Halli,
recovery at 80 wt% yield. Karnataka Brownish yellow coloured lateritic lumpy hydrated
>64 % Fe, 3.92 % SiO2, 0.52 % iron oxide lumpy ore from CN halli, Karnataka assayed 57.65
Process: stage grind to -0.3 mm, Al2O3, 1.05 % FeO, 0.03 % P,
6 deslime, gravity–WHIMS of 0.03 % S, 2.42 % LOI % Fe, 2.69 % SiO2, 0.19 % FeO, 4.40 % Al2O3, 0.08 % P, 0.03 %
gravity tails concentrate with 83 %Fe S and 10.80 % LOI and contained goethite [90 %], hematite
recovery at 78 wt% yield. [4 %], quartz [1 %], clay [5 %], gibbsite, martite, magnetite,
Table 4 Soft friable siliceous iron ore fines apatite, chlorite, pyrite[Tr]. The DAT yielded a concentrate

DECEMBER 2024 / MINES & MINERALS REPORTER 19