Journal of Minerals & Materials Characterization & Engineering, Vol. 4, No.1, pp 47-59, 2005
jmmce.org Printed in the USA. All rights reserved
47
Alteration Characteristics Of Ilmenites From South India
D. S. Rao
1
, T. V. Vijayakumar
1
, S. Prabhakar
1
, G. Bhaskar Raju
1
and T.K.Ghosh
2
1
National Metallurgical laboratory - Madras Centre,
CSIR Madras Complex, Taramani Chennai – 600 113, India
2
Institute Instrumentation Centre,
IIT, Roorkee, INDIA
Abstract:
Two different placer samples from the Navaladi and Surungudi area of Teri,
Tamilnadu, in southern India, were collected and characterized in terms of their heavy
mineral content. Mineralogical analysis on both the samples revealed the presence of
high amounts of garnet and ilmenite. The alteration characteristics of ilmenite from these
deposits were investigated by optical and electron probe microanalysis. Optical
microscopic studies revealed that the alteration of ilmenite was seen to proceed along
grain boundaries and/or fractures resulting in an amorphous to crypto- or micro-
crystalline mass resembling leucoxene. The alteration is in the nascent stage. Mineral
chemistry by electron probe micro-analysis revealed the enrichment of TiO
2
, MgO,
Al
2
O
3
, Cr
2
O
3
, SiO
2
, V
2
O
5
and Na
2
O in the altered products and loss of iron oxide and
manganese oxide from the ilmenite grains during weathering leading to the formation of
leucoxene. Similarly EPMA studies on garnet indicated that it is of the almandine variety.
This study reveals that the alteration of ilmenite by weathering leads to unstable
phases, with complex elemental distribution patterns. The physico-chemical
characteristics of the mineral and, in turn, the down-stream metallurgical processing are
affected by such alteration processes.
Key words: Placer Ilmenite, Alteration, EPMA, Navaladi, Teri
INTRODUCTION
Minerals formed by geological processes and deposited at favorable locales give
rise to economic deposits. These minerals, when subjected to post-depositional
physicochemical changes, undergo certain chemical reconstitution known as alteration.
This causes either enrichment or depletion of certain element(s), which has a bearing on
the exploration/exploitation of minerals. Alteration is primarily a disintegrative –
reconstitutive process where the distribution of elements takes place depending on the
prevalent Eh-pH conditions and the totality of the geological environment. The alteration
process gives rise to distinct phases, i.e. a parent or resistate phase and the newly formed
or neoformed authigenic phase distributed in an orderly or disorderly manner along with
the resistate
[1]
. Most alteration leads to thermodynamically unstable, incomplete,
irreversible phases that are extremely complex in elemental composition. Consequently,
the physical and chemical characteristics such as bulk density, porosity, grain density,

48
D. S. Rao, T. V. Vijayakumar, S. Prabhakar, G. Bhaskar Raju and T.K.GhoshVol. 4, No. 1
48
hardness, magnetic susceptibility and other properties are affected. These changes may
effect the down stream beneficiation/metallurgical processing of the deposit.
Ilmenite (FeTiO
3
), an important and most abundant mineral of titanium, occurs in
India along the coastal beach sands of Orissa, Andhra Pradesh, Tamilnadu, Maharastra
and Kerala states. The degree of alteration due to weathering is significant and is
independent of the provenance. Hence, it attracts the attention of scientists in different
disciplines with totally different approaches
[2-5]
. Several workers have studied ilmenite
from across the world to assess the qualitative variation from deposit to deposit
[6-9]
,
Many articles were published on the alteration of ilmenite
[4, 10-13]
. In the present study,
two different run of mine (ROM) samples, one from Navaladi (N8
o
14’15”- 8
o
16’23” Lat.
and E77
o
48’15” – 77
o
53’36” Long.) area, Trichendur district and a second from
Surangudi (9
o
06’00”-9
o
10’08” Lat. and E78
o
19’15”- 78
o
26’40”Long.) area of Teri,
Tuticorin district Tamilnadu (south India) were investigated with reference to their heavy
mineral content and the alteration characteristics of ilmenite using optical and EPMA
techniques.
MATERIALS AND METHODS
Representative placer samples were collected from the Navaladi as well as the
Teri area for this characterization study. Both the samples were processed for the
estimation of total heavy mineral (THM) content using Bromoform (CHBr
3
; specific
gravity 2.89), as a media for separation of heavier fractions from the lighter. Further, the
samples were subjected to magnetic separation using Permroll (20,000 Gauss) to separate
magnetic and non-magnetic fractions. Petro-mineralogical studies were carried out, by
stereomicroscopy as well as with a LEITZ Orthoplan optical microscope, to identify the
components of the total heavy mineral content. Magnetic and non-magnetic fractions of
heavy minerals were analysed for their mineral chemistry with the help of a JEOL EPMA
Super Probe JXA – 8600 model, with an accelerating voltage of 15 kV and a specimen
current of 2x10
-8
amps, using SPI mineral standards. Particle size analysis was carried
out using a laser diffraction particle size analyzer (CILAS 1180, France).
RESULTS
Magnetic separation:
Magnetic separation studies of the ROM samples from the Navaladi and Teri
areas indicated 33.22% and 35.70% of magnetic minerals respectively (Table 1).
Heavy media separation:
Heavy media separation studies of the ROM sample from the Navaladi area have
indicated that the sample contains around 34.20% of total heavies while the same type of

Vo. 4, No 1. Alteration Characteristics Of Ilmenites From South India
49
0100200300400500600700800900100011001200
0
20
40
60
80
100
Cumulative value (%)
Particle size (microns)
Nonmag
Mag
Head
Figure.1: Particle size analysis of Navaladi ROM sample along
with magnetic and non-magnetic fractions
study of the Teri sample indicated 37.26% heavies (Table 1). The higher amount of heavy
minerals (by heavy media separation) as compared to the magnetic separation fractions is
due to the rutile and zircon content in the sample, which did not report in the magnetic
fractions due to their non-magnetic nature.
Table 1: Distribution of Magnetic & non-magnetic and heavy & light fractions.
% Distribution% DistributionArea
MagneticNon-magnetic Heavy Light
Navaladi 33.22 66.78 34.20 65.80
Teri 35.70 64.30 37.26 62.74
Particle size distribution:
Particle size
distribution of the
ROM sample as
well as magnetic
and non-magnetic
products, from
Navaladi area,
(Figure -1) shows
that the magnetic
fraction has a finer
in particle size
distribution than the
non-magnetic and
ROM sample. The
particle size
distribution of the
ROM sample as
well as magnetic
and non-magnetic
products, from Teri
area, (Figure - 2)
shows a similar
trend (Table 2), although the Teri magnetic fraction is much finer than the non-magnetic
and ROM fractions. In addition, the mean particle size of the magnetic fraction of the
Teri sample was 75 microns while the Navaladi magnetic sample had a mean particle size
of 341 microns. Overall, the mean particle size of the Teri ROM and separated fractions
was finer than the Navaladi ROM and fractions.

50
D. S. Rao, T. V. Vijayakumar, S. Prabhakar, G. Bhaskar Raju and T.K.GhoshVol. 4, No. 1
50
05001000150020002500
0
20
40
60
80
100
Cumulative value %
Size in microns
Nonmag
Mag
Head
Figure.2: Particle size analysis of Teri ROM sample along with magnetic and
non-magnetic fractions
Mineral distribution:
Stereo-
microscopic
studies suggest
that the garnet is
the major phase
in the magnetic
fraction along
with lesser
amounts of
ilmenite in the
case of Navaladi
(Figures - 3a and
3b) while
ilmenite forms
the major phase
with garnet a
minor phase for
the Teri sample.
Zircon and rutile
were observed in
the non-magnetic
fraction of both
the samples
(Table 2). In the Teri sample, out of the total heavy minerals, the contribution of ilmenite
was found to be nearly 65%
[14]
. Most of the ilmenite and garnet from both areas show
more or less mechanically smooth surfaces.
Table 2: Distribution of minerals in various fractions
SampleMineralogy of
Magnetic fraction
Mineralogy of
non-magnetic fraction
Head (ROM)
IlmeniteGarnetOthers
*
IlmeniteGarnetOthersIlmeniteGarnetOthers
**
Navaladi19.5635.0145.43------10011.8022.3065.90
Teri64.654.8830.47------10037.561.8660.58
*Others include minerals like pyroxene which are magnetic
**Others: Include zircon, rutile as heavy minerals along with quartz, feldspar
Microscopic studies:
Microscopic studies show that the placer ilmenite occurs mostly as sub-rounded
to sub-angular grains, marked by numerous surface pits, etch marks/grooves, crescentic
pits and mesh like patterns. The garnet grains were found to be angular to subangular
with occasional subrounded grains and are characterized by conchoidal fracture. The size
of the garnet grains was found to be varying from 1000 microns to around 100 microns in

Vo. 4, No 1. Alteration Characteristics Of Ilmenites From South India
51
a
b
Fig 3a and b: Magnetic fraction of Navaladi showing
only garnet (pink) and ilmenite (black) in Fig.3a.
Fig.3b (bottom picture) Non-magnetic fraction
in the same size showing quartz and feldspar. stereo-
microscope x20
the Navaladi sample and 500 microns
to around 100 microns the Teri
sample. Reflected light microscopy
studies indicated that the ilmenite
from both areas occurs in various
shapes and sizes (Figure - 4a). Teri
ilmenite contains exsolved laths,
streaks and irregular bodies of
hematite (Figure - 5a) and vice-versa.
The ilmenite (or hematite) lamellae
thickness in the hematite (or ilmenite)
matrix show conspicuous bimodal
distribution. Two generations of
hematite or ilmenite can be
distinguished on the basis of
coarseness or fineness
[15]
. The
Ilmenite-hematite intergrowth gives
rise to an emulsion texture in the case
of Teri sample. No such intergrowth
was observed in the Navaladi sample.
In both cases, alteration of ilmenite
was observed rarely/occasionally
along grain boundaries and/or
fractures resulting in an amorphous to
crypto- or micro-crystalline mass that
resembles leucoxene (Figures - 4b -
and 5b). The intensity and mode of
alteration was different from grain to
grain. Leucoxene was present as
patches along grain margins, fractures
and rarely within ilmenite due to
alteration. The colour of the zircon in
these two areas was observed to be
reddish brown, which could be
attributed to ferruginous stain. Most
of these stained grains are fractured
and rounded. The rounded grains are dominant over subrounded and anhedral grains.
Very often the zircon is present as well developed crystals with zoning.
Mineral chemistry:
The concentration of iron and titanium along with minor and trace elements in the
ilmenite invariably play a crucial role in the selection/rejection of a specific separation
technology. Hence, the major and minor elemental composition, using electron-probe
microanalyses (EPMA), of the ilmenite specimens from the Navaladi and Teri was

52
D. S. Rao, T. V. Vijayakumar, S. Prabhakar, G. Bhaskar Raju and T.K.GhoshVol. 4, No. 1
52
Fig.4a: Various shapes and sizes of ilmenite grains from Navaladi
Fig.4b: Alteration of ilmenite grains (shown by arrow) from Navaladi
determined and reported in Table - 3 andTable - 4 respectively. The unaltered
ilmenite from both areas shows goodstoichiometry of TiO
2
(51.387 to 52.035%
for Navaladi and 49.26 to 51.195% forTeri) and FeO (45.959 to 46.966% for
Navaladi and 46.84 to 48.622% for Teri).Significant amounts of V
2
O
5
(0.280 to
0.301% for Navaladi and 0.263 to 0.288%for Teri) was recorded while SiO
2
and K
2
O
were not detected at all in any of theunaltered samples. The presence of
significant amounts of magnesium (0.081 to 0.916% for Navaladi and 0.251 to

Vo. 4, No 1. Alteration Characteristics Of Ilmenites From South India
53
Fig.5a: Hematite (white) and ilmenite (grey) intergrowth of Teri sands
0.301% for Teri) and manganese (0.103 to 0.301% for Navaladi and 0.443 to 0.717% for
Teri) indicates that the ilmenite from both areas constitute a solid solution series with
geikielite (MgTiO
3
) and pyrophanite (MnTiO
3
). As a result of these solid solutions, the
TiO
2
content of these ilmenites is lower than the ideal value (52.65%). Mg and Mn in
ilmenite are due to substitution for Fe
2+
.
Fig.5b: An altered ilmenite phase has been rimmed around the
unaltered ilmenite core of Teri placer sand.

54
D. S. Rao, T. V. Vijayakumar, S. Prabhakar, G. Bhaskar Raju and T.K.GhoshVol. 4, No. 1
54
Mineral chemistry of the associated phases, like garnet and zircon, from both
areas was carried out (Table - 4a and - 4b). End member composition of the garnet
revealed that almandine is the major species for both samples. In the case of the Teri
sample, the hematite grains were also analyzed and some were found to be ilmo-
hematites (Table - 4b). The almandine variety of garnet (also known as abrasive garnet)
is an important abrasive mineral extensively used for grinding, sand blasting, and
polishing/lapping in glass applications. In addition, it is used in ceramic industries as
well.
Table 3a: EPMA data of unaltered as well as altered ilmenite (in wt.%) of Navaladi sample
Altered ilmeniteAltered ilmeniteAltered ilmeniteIlmeniteIlmeniteIlmenite
Unaltered
Core
Altered
rim
Unaltered
Core
Altered
rim
Unaltered
Core
Altered
rim
FeO46.57946.21846.96645.959-----46.519------46.875-----
Fe2O3--------------------2.668-----8.492-----24.262
TiO251.73851.62451.63952.03588.83351.38778.52251.79668.936
Al2O30.5910.6140.6370.5212.1350.3432.1300.4643.067
MgO0.3760.8620.5270.9161.7020.0862.1140.0810.174
MnO0.2380.3010.2560.1030.0390.1430.0280.2620.002
ZnO0.0610.0260.1000.003----------0.0260.0590.038
Cr2O30.0470.1620.0330.0490.1490.0020.1460.0490.143
V2O50.2890.2800.2890.3010.5120.2900.4730.2970.429
SiO2--------------------1.798-----2.675-----1.161
Na2O-----0.049----------0.221-----0.115-----0.236
CaO0.0010.391-----0.0130.7230.1290.3400.0290.190
Total99.920100.527100.44798.90098.78098.89995.06199.91298.638
Table 3b: EPMA data of garnet (in wt.%) of Navaladi sample
GarnetGarnetGarnetZircon
SiO239.45438.46838.11531.387
Al2O320.67720.62120.647-----
FeO29.57833.05630.5400.003
MgO7.6054.3576.0170.053
MnO0.3571.0110.6220.010
CaO0.8111.2871.8400.003
Na2O0.047---------------
TiO20.0520.0640.049-----
Cr2O30.0310.0870.1320.042
ZnO0.1220.049----------
ZrO2---------------66.987
HfO2---------------0.610
Total98.73499.00097.96299.097
Formulae based on 24 (O)
Si6.19046.15466.0994
Al3.82403.88883.8945
Fe3.88124.42314.0873
Mg1.77881.03921.4354
Mn0.04750.13710.0844
Ca0.13640.22060.3155
Na0.0142----------
Ti0.00620.00760.0059
Cr0.00380.01100.0167
Zn0.01410.0058-----
Total15.887815.887815.9391

Vo. 4, No 1. Alteration Characteristics Of Ilmenites From South India
55
Table 4a: EPMA data of unaltered as well as altered ilmenite (in wt.%) of Teri sample
Altered ilmeniteAltered ilmeniteAltered ilmeniteIlmeniteIlmenite
Unaltered
Core
Altered
rim
Unaltered
Core
Altered
rim
Unaltered
Core
Altered
rim
FeO48.23448.62246.840-----47.675-----47.937-----
Fe2O3---------------2.638-----18.154-----8.102
TiO250.20949.26051.19588.63850.34074.42249.75487.493
Al2O30.8080.4830.4082.5890.4542.4360.3692.247
MgO0.2510.3010.7580.9040.5091.1490.3740.714
MnO0.6590.7170.610-----0.4340.0660.443-----
ZnO0.077-----0.020-----0.0070.0480.016-----
Cr2O30.0090.0050.0030.1530.0190.1330.0730.235
V2O50.2880.2810.2630.5320.2800.4550.2860.523
SiO2---------------1.382-----1.165-----1.329
Na2O---------------0.334-----0.030-----0.139
CaO0.0200.0110.3690.0010.2110.0030.153
Total100.55599.669100.10997.22499.71998.26799.25598.935
Table 4b: EPMA data of associated phases (in wt.%) of Teri sample
GarnetZirconQuartzHematiteIlmo-
hematite
Rutile
FeO29.4140.0540.032----------0.109
Fe2O3---------------96.08977.013-----
TiO20.158-----0.0270.24522.04598.231
Al2O321.586----------0.9890.6571.155
MgO10.027---------------0.004-----
MnO0.317-----0.0220.2050.2130.033
ZnO----------0.0880.0340.0070.023
Cr2O30.0230.009-----0.2070.2010.401
V2O50.0010.0020.0020.0030.1050.582
SiO238.00331.59699.1590.0980.009-----
Na2O----------0.011---------------
K2O-----0.010-----0.003----------
CaO0.764----------0.0010.0170.007
ZrO2-----67.019--------------------
HfO2-----0.584--------------------
100.29399.27499.34197.874100.276100.541
Major and minor elemental analyses of the altered and unaltered portions of three
different ilmenite grains from both the areas were carried out (Tables - 3 and - 4). The
analyses of unaltered ilmenite portions compared well with natural ilmenites. The altered
ilmenite portions are enriched in TiO
2
(68.936 to 88.833% for Navaladi and 74.422 to
88.638% for Teri), MgO (0.174 to 2.114% for Navaladi and 0.714 to 1.149% for Teri),
Al
2
O
3
(2.135 to 3.067% for Navaladi and 2.247 to 2.589% for Teri), Cr
2
O
3
(0.143 to
0.149% for Navaladi and 0.133 to 0.235% for Teri), SiO
2
(1.161 to 2.675% for Navaladi
and 1.165 to 1.382% for Teri), V
2
O
5
(0.429 to 0.512% for Navaladi and 0.455 to 0.532%
for Teri) and Na
2
O (0.115 to 0.236% for Navaladi and 0.030 to 0.334% for Teri) and
decreased in MnO and FeO content. The alteration starts with the removal of Fe
+2
then

56
D. S. Rao, T. V. Vijayakumar, S. Prabhakar, G. Bhaskar Raju and T.K.GhoshVol. 4, No. 1
56
the electrostatic charge is balanced by oxidising the remaining iron. The removal of iron
is compensated by the addition of other elements (Ti, Mg, Al, Si) into the structure along
with (OH) ions into the mineral lattice. Thus, the sum total of the percentages from the
altered portions of ilmenite varies from 95.061% to 98.780% for Navaladi and from
97.224% to 98.935% for Teri, which may be due to the incorporation of hydroxyl ions
into the structure during weathering. Similar observations have also been made by many
authors
[2, 5, 16-17]
.
Dissolution and/or oxidation of iron from ilmenite in natural water or in acidic
water leads to an enrichment of titanium and other elements in the residuum, which may
be the main cause for ilmenite alteration
[18]
. Though ilmenite alteration is neither
uniform nor continuous, the weathering mechanism is illustrated as a two stage process
[16]
and/or a multistage process
[10-11]
. However, the present mineral chemistry suggests
that the initial step involving a ferrous-ferric iron transformation stage is relatively
advanced (indicated by a relatively low content of ferrous iron or removal of iron and
enhancement of titanium), which is a common low temperature geochemical process. In
general, such a process leads to incomplete alteration of ilmenite and the co-existence of
ilmenite and leucoxene. The composition and grade/quality changes noticed in these
placer ilmenites could only be due to the exogenic processes undergone by the mineral
after its release from those Precambrian metasedimentary crystalline parent rocks. The
heavy mineral assemblage in this sector is suggestive of provenance consisting
principally of high–grade metamorphic (granulite facies) rocks, principally of khondalite
(garnet-sillimanite-graphite-gneisses), charnokites and granitic gneisses (unclassified
crystalline rocks), bordered by the sedimentary rocks exposed along the eastern coastal
plains which are the rock types of Tamilnadu
[14]
. However, the extent of alteration
depends on the geological history of the deposit and also the weathering environments
[2,
11]
. The degree of alteration of different ilmenite deposits in the world is quite varied;
those of Zululand (South Africa) and Brazil being altered relatively very little but those
of Australia and Florida (U.S.A.) show extensive alteration
[11, 19]
. Similarly in the case of
the Indian beach sand ilmenites of the different regions; Kerala state ilmenite underwent
maximum alteration while the Tamilnadu state ilmenite was altered moderately and
Orissa ilmenites of the Chatrapur coast have undergone the least weathering
[3]
.
DISCUSSION AND CONCLUSIONS
Mineralogy:
Teri sample contains higher amounts of ilmenite and minor amounts of garnet
while the Navaladi sample contains higher amounts of garnet and good amount of
ilmenite. In addition both samples contain traces of rutile and zircon, with hematite
observed in the Teri sample. The iron content in the ilmenite concentrate is likely to be
more in the Teri sample due to the presence of exsolved hematite. The hematite lamellae
in the ilmenite and ilmenite lamellae in hematite indicate that they are exsolved from
FeTiO
3
-Fe
2
O
3
solid solution
[20]
. The presence of ilmo-hematite along with hematite and
ilmenite also attests that they are exsolved from FeTiO
3
-Fe
2
O
3
solid solution. The two

Vo. 4, No 1. Alteration Characteristics Of Ilmenites From South India
57
generations of ilmenite and hematite may indicate different periods of crystallization
[15]
.
The coarser first generation lamellae were probably formed at higher temperatures
(530
o
C – 600
o
C) by a fast diffusion process, where-as the finer second generation
lamellae may represent a later stage of crystallization in the range of 450
o
C – 500
o
C and
might have been produced by slow diffusion processes
[20-21]
. The ilmenites of both the
areas are altered along grain boundaries and fractures. This alteration leads to formation
of leucoxene. Electron probe microanalysis data indicate that the ilmenite is in solid
solution with pyrophanite and geikielite and the alteration leads to enrichment of TiO
2
,
MgO, Al
2
O
3
, Cr
2
O
3
, SiO
2
, V
2
O
5
and Na
2
O with loss of iron and manganese oxides.
Trace elements like chromium, vanadium, calcium and magnesium in the ilmenite are
with-in acceptable limits for the processing industry. These alteration products could be
due to the exogenic processes that operated on these ilmenites after their release from the
parent rocks. The studies further indicated that the alteration of ilmenite is not uniform
and the extent of alteration varies from grain to grain. Almandine is the major species of
garnet revealed from the mineral chemistry for both areas. The natural size range of these
almandine garnets indicates that they are ideally suited for sand blasting or water jet
cutting purposes.
As mentioned above, the source rocks of these placer minerals are the charnokite
and khondalite group of rocks of the Precambrian Eastern Ghats complex, which crops
out widely in the Tamilnadu region. The Eastern Ghats rocks of Precambrian contain
ilmenite, zircon and garnet among others as minor accessory minerals. Hence, the Eastern
Ghats provenance appears to be the major source for these mineral assemblages in these
two regions.
Implications in processing:
Ilmenite, which is gradually converting to leucoxene in these two deposits under
oxidising conditions, leaving enriched residue of TiO
2
and SiO
2
along with others, results
in the formation of porous grains of altered ilmenite/leucoxene. The pores may remain
open or may get filled by a variety of secondary minerals, which affect their
grade/quality. These porous grains have low density and low magnetic susceptibility
(because of changing iron content) leading to concentration problems. Wort and Jones
studied the changes in magnetic susceptibility that takes place when an ilmenite alters
and opined that the changes are related to the chemical composition
[22]
. Such differences
in physical properties between altered/oxidised ilmenite and fresh/unaltered ilmenite
were often very great and have a definite influence on beneficiation/metallurgical down
stream processes. The altered or oxidised ores behave very differently in the processes
compared to the fresh unaltered ores. It is well known that ilmenite is soluble in H
2
SO
4
where as rutile is not. However, the degree of solubility of ilmenite varies depending on
the extent of alteration. Regardless of the higher TiO
2
content in the altered ilmenite, its
solubility in H
2
SO
4
decreases with increasing degree of alteration
[23]
. In other words, the
high ferric iron content of the altered ilmenite clearly demands a reduction process rather
than a sulphate process for TiO
2
production
[13,24]
. Similarly the rate of reduction and size
of the iron particles formed, decreases (during reduction) with increasing degree of

58
D. S. Rao, T. V. Vijayakumar, S. Prabhakar, G. Bhaskar Raju and T.K.GhoshVol. 4, No. 1
58
weathering of the ilmenite concentrate
[25]
. In other words stoichiometric ilmenite reduces
faster than pseudorutile, which is a product of weathering. Hence, the degree of
weathering or alteration can be an indicator of a minerals’ economic value.
Compositional characterization by instrumental techniques as used in this study, would
not only help us to adopt better methods for industrial processing, but also facilitate the
production of different grades of synthetic rutile.
Acknowledgements:
The authors wish to acknowledge Indian Ocean Garnet Sands Pvt. Limited,
Tuticorin for providing facilities for collection of the samples and Council of Scientific
and Industrial Research, India for financial assistance extended under Network project
(CMM – 0023). Thanks are also due to The Director, National Metallurgical Laboratory
for his keen interest and permission to publish this work.
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Delhi.
2. Suresh Babu, D.S., Thomas, K.A., Mohan Das, P.N. and Damodaran, A.D. (1994)
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