Access over 20 million homework & study documents

Process Mineralogy Applied to the Beneficiation of High Alumina Iron Ores—A Case Study

Content type
User Generated
Type
Study Guide
Rating
Showing Page:
1/4
Process Mineralogy Applied to the Beneficiation of High Alumina Iron Ores… 489
Process Mineralogy Applied to the Beneficiation of
High Alumina Iron OresA Case Study
Vinod Kumar*, G.N. Jadhav**, N.K. Khosla**, U.S. Chattoraj*,
K.K. Bhattacharyya* and S.P. Mehrotra*
*Mineral Processing Division,
National Metallurgical Laboratory, Jamshedpur
**Department of Earth Sciences,
Indian Institute of Technology Bombay
ABSTRACT: This work has been carried out on Noamundi iron ore deposits for their characterization and to
investigate the possibility of physical beneficiation of the Iron bearing minerals present in this deposit. The
ultimate objective of this study is to evaluate the possibility of the physical beneficiation of this ore to make it
suitable for the blast furnace route of iron production. The present investigation relies on petrography and ore
mineralogical characterization, ore textures (primary, secondary, metamorphic), liberation characters of ore
types, and its impact on the mineral beneficiation methods to produce quality concentrate. In addition to this,
representative samples of each ore type were employed for detailed investigation by using XRD, SEM-EDS
and Cathodoluminescence (CL) studies for confirmation and reconfirmation of major as well as minor ore
minerals and associated gangue minerals. This research work reiterates that the role of ore-gangue
mineralogy is very useful in evaluating the separation efficacy of beneficiation processes. The results
obtained for the gravity separation process namely MGS, and the magnetic separation process, namely
WHIMS could be easily explained on the basis of process mineralogical studies of the product of
beneficiation.
1. INTRODUCTION
Iron ore is an important raw material for iron and
steel industry, and its quality dictates the
production strategy, and ultimately, the quality
and cost of steel. It is a well established fact that,
higher the alumina content in the feed for blast
furnaces, poorer are the properties of iron and
steel, virtually on all fronts.
Depletion of high grade iron ore reserves
coupled with increasing market pressure for good
grade iron ores/concentrates and the threat of
environmental pollution has made us to realize the
need to maximize the utilization efficiency of
availability of large tonnage of low grade iron
ores/fines containing high alumina in our country.
The iron ore body around Noamundi mainly
consists of hematite and has been classified as
massive, hard, laminated, lateritic, powdery,
hematite breccias, consolidated hematite debris,
banded hematite jasper, banded hematite quartzite
and banded hematite shale, soft ore, friable, flaky
and biscuity ore (Majumdar et al. 2005). In
addition to this, there is large tonnage of non-
usable iron ores due to their high alumina content.
This study was carried out with an objective to
characterize the non-usable iron ores containing
alumina as high as around 10%-12% in different
types of iron.
2. SIZE ANALYSIS
Size analysis of the iron ore samples collected
from the Noamundi mines, indicated two broad
classes of size distribution namely, coarse
distributed (66-81% above 8mm) banded
hematite jasper, shaly ore and lateritic ore, and
finely distributed (36-27 % above 8mm) hard and
composite ore. The Composite ore has more
uniform size distribution because of its blended
nature (table 1).

Sign up to view the full document!

lock_open Sign Up
Showing Page:
2/4
490 Mineral Processing Technology (MPT 2007)
Table 1: Size analysis of the samples of high alumina iron ores
Particle
Size, mm
Hard
(Wt%)
Lateritic
(Wt)
BHJ
( Wt%)
Composite
(Wt%)
+40
7.00
19.90
12.50
4.70
+25
17.50
23.30
11.80
4.50
+15
12.50
39.60
41.50
18.70
+8
10.00
2.20
7.20
11.50
+6.3
3.00
2.50
2.50
9.20
+4
2.50
1.20
3.10
10.10
+2.38
5.10
1.20
2.90
12.20
+1.19
10.20
2.50
1.30
6.50
+0.595
24.00
1.30
2.90
3.40
+0.297
2.50
2.20
2.10
3.20
+0.150
1.50
1.20
2.40
2.30
+0.075
2.20
1.30
3.20
2.20
+0.045
1.30
0.60
3.70
3.60
+0.026
0.20
0.30
1.10
3.20
-0.026
0.50
0.70
1.80
4.70
Head
100.0
100.0
100.0
100.0
3. CHEMICAL ANALYSIS
Chemical analysis of the samples of hard ore,
lateritic ore, BHJ, shaly ore and composite ore
was carried out, to know the concentration of iron
and presence of deleterious elements such as
alumina, silica, sulfur and phosphorous. Banded
hematite jasper and shaly ores show higher
alumina content in comparison to the other ore-
types, because of the high modal distribution of
clay minerals (45%-50%) in BHJ and shaly ores.
The results of chemical analysis are presented in
table 2.
Table 2: Chemical analysis of samples
Constitu
ents
Ore type
Comp
osite
( % )
Hard
(%)
Later
itic
(%)
BHJ
(%)
Shaly
( % )
Fe
58.62
59.12
57.6
54.15
55.25
Al
2
O
3
8.66
8.52
9.32
12.52
11.52
SiO
2
5.32
5.01
5.75
7.35
6.89
S
0.52
0.45
0.67
0.75
0.68
P
0.25
0.30
0.42
0.35
0.57
4. MINERALOGICAL ANALYSIS
Mineralogical examination of the samples
indicate that in low-grade iron ores, the phases of
minerals present in order of abundance are mainly
iron oxides/hydroxides, aluminous gangue,
silicates and traces of sulphides. Oxide/hydroxide
phases mainly comprise of hematite, goethite and
limonite (Kumar et.al., 2002). Gangue mineral
association (confirmed by ore petrography, XRD
and SEM-EDS analysis) is mainly in the form of
aluminous and siliceous minerals consisting of
gibbsite, diaspore, bohemite, clays (kaolinite, illite
etc), apatite, chert, collophane, jasper and quartz.
Trace of sulphide phases were identified based on
ore petrography and mainly comprised of pyrite,
arsenopyrite, pyrrhotite, marcasite and cubanite.
Detailed microscopic (transmitted and reflected
light) characterization was carried out to delineate
various phases, their textual arrangement, shape
and size for effective liberation. The gangue
minerals are mostly in disseminated form,
randomly oriented and in many cases it has been
observed as enclosed in a matrix of iron ore
minerals such as hematite and goethite. In such

Sign up to view the full document!

lock_open Sign Up
Showing Page:
3/4

Sign up to view the full document!

lock_open Sign Up
End of Preview - Want to read all 4 pages?
Access Now
Unformatted Attachment Preview
Process Mineralogy Applied to the Beneficiation of High Alumina Iron Ores—A Case Study Vinod Kumar*, G.N. Jadhav**, N.K. Khosla**, U.S. Chattoraj*, K.K. Bhattacharyya* and S.P. Mehrotra* *Mineral Processing Division, National Metallurgical Laboratory, Jamshedpur **Department of Earth Sciences, Indian Institute of Technology Bombay Abstract: This work has been carried out on Noamundi iron ore deposits for their characterization and to investigate the possibility of physical beneficiation of the Iron bearing minerals present in this deposit. The ultimate objective of this study is to evaluate the possibility of the physical beneficiation of this ore to make it suitable for the blast furnace route of iron production. The present investigation relies on petrography and ore mineralogical characterization, ore textures (primary, secondary, metamorphic), liberation characters of ore types, and its impact on the mineral beneficiation methods to produce quality concentrate. In addition to this, representative samples of each ore type were employed for detailed investigation by using XRD, SEM-EDS and Cathodoluminescence (CL) studies for confirmation and reconfirmation of major as wel ...
Purchase document to see full attachment
User generated content is uploaded by users for the purposes of learning and should be used following Studypool's honor code & terms of service.

Anonymous
Great content here. Definitely a returning customer.

Studypool
4.7
Trustpilot
4.5
Sitejabber
4.4