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Journal of Minerals & M aterials Characterization & Engineering, Vol. 8, No.6, pp 479-493, 2009
jmmce.org Printed in the USA. All rights reserved
Characterization Studies on Ilmenite of Ullal and Suratkal along
Karnataka Coastline, West Coast of India
M. Sundararajan*, K.H. Bhat, N. Babu, M.E.K. Janaki, P.N. Mohan Das
National Institute for Interdisciplinary Science and Technology,
(Council of Scientific and Industrial Research), Trivandrum – 695019, India.
*Corresponding Author: rajanmsundar77@yah oo.com, email@example.com,
Phone: 0091-471-2515285 / 2515250, Fax: 0091-471-2491712
Granulometric and heavy mineral investigations of sediments along the coastal region from
Ullal beach to Suratkal beaches along western coast of Karnataka were undertaken
systematically. Texturally the beach sediments were medium size sand in the southern region,
where as fine size sand was observed in the northern region. Unimodal, moderately sorted to
moderately well sorted, symmetrically skewed and mesokurtic nature was observed in the
southern region of the study area. In the northern sector, the grain size distribution was
observed to be unimodal, moderately well sorted to well sorted, coarse skewed and
mesokurtic in nature. As far as organic carbon and calcium carbonate contents are
concerned, the trend show ed an increase from south to north ern region. The con centration of
heavy minerals in the southern region was higher compared to the study area of northern
region. Further the heavy mineral concentration was more at either side of the mouth bar of
the Netravathi River. Subsequent to heavy mineral separation the ilmenite fraction was
isolated using magnetic isodynamic separator. It was further characterized by chemical
analysis of major constituents such as TiO2 and FeO. A mineralogical and morphological
investigation of the mineral was evaluated using techniques such as SEM and EDAX .The
degree of alteration of ilmenite was investigated using X.R.D analysis.
Key Words: Beach sand, ilmenite, total heavy minerals XRD, SEM-EDAX.
Heavy minerals such as ilmenite, monazite, zircon, sillimanite and garnets are important
economic resource as they are useful in many industries for various purposes. The known
deposits of heavy minerals in India are at Chavara (Kerala), Rathanagir (Maharastra),
480 M. Sundararajan, K.H. Bhat, N. Babu, M.E.K. Janaki, P.N. Mohan Das Vol.8, No.6
Manavalakurichi (Tamil Nadu) and Ganjam (Orissa). Ilmenite (FeTiO3), an important and most
abundant mineral of titanium, occurs in India along the coastal beach sands. 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 [1-5]. The
world reserves of economic sources of titanium are estimated to be approximately 300 million
tons that contained TiO2 . However, when the production of ilmenite is looked into, the ratio
of production of ilmenite to the reserves is only 0.1 % while the countries such as Malaysia (7
%), USA (3 %), Australia (1 %) and Brazil (1.8 %) keep better ratio . India is blessed with
large reserves of strategic and economically important heavy minerals such as leucoxene, zircon,
monazite, ilmenite, rutile, garnet and sillimanite. In India, a two stage model for pseudo-rutile
formation from the ilmenites of Manavalakurichi region has been reported  and the alteration
of ilmenites from the river Valliyar and Manavalakurichi beach has been outlined . Along the
Ratnagiri coast, the provenance of offshore ilmenite placers, based on geochemical studies has
been dealt in detail [9, 10]. From South India, a detailed account of alteration characteristics of
ilmenites has been enunciated . Numerous unknown concentrations of placers occur but no
systematic and detailed studies were made particularly in the study area. However, detailed
investigations of such less known; commercially unviable mineral reserves is necessary by virtue
of fast depletion of commercial deposits and when lean deposits have to be exploited. The
present paper deals with the detailed mineralogical, textural and characterazation studies of
samples from the south of Karnataka coast.
2. STUDY AREA
The study area is from Ullal to Suratkal in southern region of coastal Karnataka. The width of the
beach varies from place to place with a range of 20 to 170 m. Fourteen locations were selected
for sampling. For convenience of discussion the study area has been grouped into three sectors
viz. Ullal, Thannirbhavi and Panambur sectors.
Fourteen stations were fixed for sample collection. In each station beach samples up to a depth of
about 30cm were collected from the foreshore, berm and backshore as well as 50m apart along
the beach and all these were thoroughly mixed and the fourteen representatives were collected
for the present study (Fig.1).
Samples were subjected to granulometric analysis following Folk and Ward method .
Fraction-wise separations of light and heavy minerals were carried out using bromoform in
fractions of +45 to –230 A.S.T.M mesh following the procedure mentioned in . For XRD
analysis, the ilmenite grains were powdered and the powdered samples were subjected to X-ray
diffraction with scan angle (2ө) ranging from 10o to 60o, using a Phillip X’ Pert X – ray
diffractometer. Jeol-JSM 5600 LV microscope was used for Scanning Electron Microscopic
studies of ilmenite samples in order to understand mineral alteration and micro morphology.
Powdered ilmenite was brought into solution by fusion with KHSO4 and dissolution in hot dilute
H2SO4. Titanium was determined by reducing titanium IV to titanium III using aluminum metal
Vol.8, No.6 Characterization Studies on Ilmenite of Ullal and Suratkal 481
and titrating with standard ferric ammonium sulphate . The total iron was estimated by
stannous chloride reduction-K2Cr2O7 titration method. The content of FeO in the ilmenite was
analysed by treating the powdered ilmenite with HF-H2SO4 mixture and titrating with standard
50' 74° 55'
Figure 1. Location map and sampling station.
4. RESULTS AND DISCUSSION
4.1 Grain Size Characteristics
The samples K1 to K6 come under medium sand whereas the samples K6 to K 14 come under
fine sand category. Most of the samples from the study area are moderately well sorted. The
sample K1 is poorly sorted, K11 and K14 are well sorted and the rest of the samples are
moderately well sorted. Majority of the samples are mesokurtic in nature. K5, K11 and K12
482 M. Sundararajan, K.H. Bhat, N. Babu, M.E.K. Janaki, P.N. Mohan Das Vol.8, No.6
show platykurtic characteristics with kurtosis value 0.85, 0.90 and 0.87 respectively. Except K1
and K12 all the other samples show unimodality. K1 and K12 show bimodal characteristics
(Table 1). On an average the deposit type is fine skewed, moderately well sorted, mesokurtic
and unimodal along the coast.
The frequency curves plotted for the sands of Karnataka coast indicate bimodal distribution for
K1 and K12 locations i.e. these deposits are formed from multi source of origin; all the
remaining samples show unimodal distribution (Fig.2) i.e. single source of origin. These Samples
K1 and K12 sectors have their peaks at 1.5Ø and 2.5 Ø, 1.5 Ø and 3 Ø (Table 1) respectively.
The cumulative curves are plotted on arithmetic probability graph for Karnataka coast sands
(Figure.3). The size parameters have been calculated from the phi values of the cumulative
curves. The cumulative curves of the sediments show over all dominance of saltation load in all
the samples. The suspension and traction load are the least in those sectors. The truncation points
between traction and saltation are predominantly around 0 Ø and that of saltation – suspension at
2.5 Ø for all the sediments. However, uniform distributions are found in all the samples.
Table 1. Textural parameters of Sediments.
S. No Mean Mean
Description Sorting Sorting Description Skewness Skewness Description Kurtosis Kurtosis
Description Sample Typ
K1 1.42 Medium Sand 1.03 Poorly Sorted 0.28 Fine Skewed 1.00 Mesokurtic Bimodal
K2 1.63 Medium Sand 0.80 Moderately Sorted 0.05 Symmetrical 0.99 Mesokurtic Unimodal
K3 1.19 Medium Sand 0.72 Moderately Sorted 0.10 Symmetrical 1.02 Mesokurtic Unimodal
K4 1.22 Medium Sand 0.67 Moderately Well Sorted0.01 Symmetrical 1.00 Mesokurtic Unimodal
K5 1.82 Medium Sand 0.81 Moderately Sorted -0.06 Symmetrical 0.85 Platykurtic Unimodal
K6 1.51 Medium Sand 0.86 Moderately Sorted -0.06 Symmetrical 0.91 Mesokurtic Unimodal
K7 2.37 Fine Sand 0.67 Moderately Well Sorted-0.34 Very Coarse Skewed 1.38 Leptokurtic Unimodal
K8 2.42 Fine Sand 0.57 Moderately Well Sorted-0.30 Very Coarse Skewed 1.16 Leptokurtic Unimodal
K9 2.28 Fine Sand 0.52 Moderately Well Sorted-0.12 Coarse Skewed 0.91 Mesokurtic Unimodal
K10 2.10 Fine Sand 0.63 Moderately Well Sorted-0.11 Coarse Skewed 0.93 Mesokurtic Unimodal
K11 2.46 Fine Sand 0.41 Well Sorted -0.17 Coarse Skewed 0.90 Platykurtic Unimodal
K12 2.19 Fine Sand 0.60 Moderately Well Sorted-0.22 Coarse Skewed 0.87 Platykurtic Bimodal
K13 2.22 Fine Sand 0.51 Moderately Well Sorted-0.10 Symmetrical 0.95 Mesokurtic Unimodal
K14 2.51 Fine Sand 0.44 Well Sorted -0.26 Coarse Skewed 1.01 Mesokurtic Unimodal
Avg 1.95 F in e Sand 0.66 Moderately Well Sorted -0.09 Fine Skewed 0.99 Mesokurtic Unimodal
Vol.8, No.6 Characterization Studies on Ilmenite of Ullal and Suratkal 483
Fig. 2. Frequency weight% curve for the beach sediments of Karnataka coast.
Phi Va l ue
Cumulative weight percentage
Fig. 3. Cumulative curves for the beach sediments of Karnataka coast.
4.2 Heavy Mineral Distribution
The heavy mineral percentage varies from 2.75% at K5 to 1.64% at K12. The concentration is
more than 10% at stations K2, K4, K5 and K6. K8 shows medium concentration. At other
stations the concentration is still low.
484 M. Sundararajan, K.H. Bhat, N. Babu, M.E.K. Janaki, P.N. Mohan Das Vol.8, No.6
Heavy mineral distribution in the stations (K1, K2, K5 and K6) shows bimodal character with
well-developed peak at 2 phi and 3 phi sizes (Figure 4). This bimodality suggests that the heavies
are contributed by two sources, primary by waves and littoral currents and secondary, by fluvial
changes of Netravathi River.
The unimodal curves of the stations (K3, K4, K7, K8, and K11) (Figure 4) show, well developed
peak at 2ø, 2ø, 3ø, 3ø, 3ø and 2.5ø respectively and suggest that the heavies are contributed by a
single source i.e. either wave or littoral currents. Station K9 shows polymodal distribution curve
having peaks at 1.5ø, 2.5ø and 3.5ø and reveals that there could be two or more sources involved
in the heavies distribution.
Vol.8, No.6 Characterization Studies on Ilmenite of Ullal and Suratkal 485
Figure 4. Heavy Mineral Distribution of Karnataka Coast.
486 M. Sundararajan, K.H. Bhat, N. Babu, M.E.K. Janaki, P.N. Mohan Das Vol.8, No.6
4.3 Characterization of Ilmenite
The ilmenite samples separated from Ullal beach contain about 49.61% TiO2, 23.58% FeO and
14.45% Fe2O3. Thannirbhavi samples also show almost similar composition with respect to TiO2
and iron contents whereas the samples from Panambur beach contain very low TiO2 and iron
contents (Figure 5). In all the beaches the FeO content is considerably high showing that
alteration is minimum in the study area.
The chemistry of iron and titanium in the ilmenite mineral structure is the most evident and
direct indicator of the stage of alteration undergone. While the oxidation stage of iron is defined
by the ferrous-ferric conversion, as the first stage of alteration, the latter process is the function
of the leaching of iron from the mineral structure and the corresponding enrichment of titanium.
Thus the study of major elements of ilmenite has implications in the assessment of the quality of
Different elemental ratios have been proposed to delineate the weathering mechanisms in
ilmenite. Forst et al  has classified ilmenite alteration into four stages based on the
Ti/(Ti+Fe) ratios. The terminology of those stages in the order of increasing stage of alteration is
as follows. The Ti/(Ti+Fe) values are given in brackets. Ferrian Ilmenite (<0.5), ‘Hydrated
Ilmenite’ (0.5 – 0.6), ‘Pseudorutile’ (0.6 – 0.7) and ‘Leucoxene’ (>0.7). This system has been
adopted in this work for the chemical characterization of ilmenite based on major element
chemistry. The chemical analysis carried out for the present study, is detailed in Table 2. It was
observed that the ilmenite exhibited different stages of alteration at different locations as
hydrated ilmenite (0.51%) in Ullal beach, Ferrian ilmenite (0.43%) in Thannirbhavi beach, and
Ferrian ilmenite (0.42%) in Penambur beach.
Table 2. Chemical analysis and alteration stages of ilmenite from beach sand of Karnataka.
Sample LocationFeO % Fe2O3
Ullal 23.58 14.45 49.61 28.44 0.51 Hydrated Ilmenite
Tannirbhavi 29.16 13.91 41.97 32.4 0.43 Ferrian Ilmenite
Panambur 15.99 0.93 15.87 13.08 0.42 Ferrian Ilmenite
Figure 5. Major constituents of ilmenite from Karnataka coast.
Vol.8, No.6 Characterization Studies on Ilmenite of Ullal and Suratkal 487
4.3.1 SEM and EDAX
Ilmenite of Karnataka samples has been studied under scanning electron microscope (SEM) and
has been analysed with EDAX. The analyses show that the ilmenite of Ullal beach contains Ti
and Fe around 31.82 and 20.08 % by weight respectively with minor impurities of alumina,
manganese and silica. The weight percentages of the Ti, Fe, Al, Mn and Si are summarized in
Table 3 and Figure.6.
Thannirbhavi beach sample contains Ti and Fe around 30.14 and 34.91 % by weight respectively
with minor impurities of alumina, manganese, and magnesium and silica around 3.43, 2.37, 0.82
and 12.07% respectively. Penambur beach contains only Ti and Fe as major elements and the
weight percentage of Ti and iron is around 41.69 and 41.01, respectively.
Table 3. Chemical composition of ilmenite by EDAX analysis.
Sample Location Wt%
Panambur Ti 41.6932.4
488 M. Sundararajan, K.H. Bhat, N. Babu, M.E.K. Janaki, P.N. Mohan Das Vol.8, No.6
Figure 6. Spectral results of ilmenite from EDAX.
X-ray diffraction pattern of ilmenite of the Ullal, Thannirbhavi and Panambur shows the
presence of only ilmenite peaks (Fig. 7) which reveals that the sediments in these study area have
not undergone much alteration.
Vol.8, No.6 Characterization Studies on Ilmenite of Ullal and Suratkal 489
10 20 30 40 50 60
Figure 7. X-Ray diffractrograms of representative ilmenite of the beach sediments of Karnataka.
4.3.3 Morphological studies using SEM
The micro features of monomineralic mineral and ilmenite of South Karnataka samples are
presented in Fig.8 (a-c), 9(d-g), 10 (h-k). Krinsley and Doornkamp,  studied the surface
textures of the quartz to understand the post depositional or digenetic history of the sediments.
In India, Mallik, Mallik et al., Anil Cherian et al., and Amber et al., [18-21] have studied the
micro features of both heavy and light minerals to understand the digenetic and depositional
history of the sediments. In the present investigations sub-rounded grains are observed in Ullal
beach (Fig. 8a). Stepped furrow and precipitation on the ilmenite grain (Figures 8 b and c)
portrayed grinding, collision and precipitation due to weathering in the study area. In
Thannirbhavi beach, the sediment grains are 100um – 200um in size and unhedral in shape (Fig.
9d). Breakage blocks as well as precipitation are observed on ilmenite grain (Fig. 9 e) due to the
process of collision of grains in sub aqueous condition. (Fig 9 f and g) show microstructures of
ilmenite under low and high resolution, which exhibit etch V’s as well as precipitation due to
chemical process in sub aqueous condition.
Micro features of samples of Panambur beach of Karnataka are presented in Figures 10 (h, i, j
and k). Euhedral to unhedral shapes are also observed (Fig 10 h). 50 um – 150 um size grains are
observed in this beach. Fractured ilmenite grains are seen (Fig 10i) due to the process of collision
of particles under wave action in the tidal zone . Figures j and k are microstructures of
ilmenite grain under low and high resolution, which exhibit 100 % altered nature due to chemical
process and precipitation. SEM and EDAX analysis, suggest that Penambur ilmenite grains are
more altered than the Ullal and Thannirbhavi ilmenite.
490 M. Sundararajan, K.H. Bhat, N. Babu, M.E.K. Janaki, P.N. Mohan Das Vol.8, No.6
a) Grains are sub rounded b) Weathered ilmenite
c) Grain showing rims
Figure 8 (a,b,c). Scanning Electron Micrographs of ilmenite from the Ullal Beach.
d) Grains are unhedral e) Grain showing breaking block and precipitation
f) Irregular grain showing angular edges g) Conchoidal fracture
Figure 9 (d,e,g,f). Scanning Electron Micrographs of ilmenite from the Tanivar bavi Beach.
Vol.8, No.6 Characterization Studies on Ilmenite of Ullal and Suratkal 491
h) Grain are euhedral and unhedral i) Fractured ilmenite
j) Altered ilmenite grain k) Macro view of Altered ilmenite.
Figure 10 (h,i,j,k). Scanning Electron Micrographs of ilmenite from the Panambur Beach.
Texturally the Ullal beach sediments are medium in grain size, moderately to poorly sorted and
fine to symmetrical skewed, mesokurtic in kurtosis and bimodal in distribution, whereas
Thannirbhavi beach sands show medium to fine sand, moderately sorted, symmetrical – very
coarse skewed in skewness and leptokurtic – mesokurtic in kurtosis. Unimodal distribution is
registered in this beach. Penambur beach sediments are fine in nature, well sorted to moderately
well sorted, coarse skewed, and mesokurtic to platykurtic in kurtosis. Domination of unimodal
distribution prevailed in this beach. As far as heavy mineral is concerned, Thannirbhavi beach
sector shows a higher percentage than the sediments in Ullal and Penambur beaches. Analysis of
TiO2 percentage by wet chemical methods show higher percentage in Ullal than in Panambur and
Thannirbhave beach sand which was further substantiated by EDAX analysis. X-ray diffraction
analysis on ilmenite of Ullal, Thannirbhave and Panambur beach sediments show the peaks of
only ilmenite, which is indicative of nonweathering nature of mineral. Scanning Electron
Micrographs examinination reveals that the weathering mechanism, both mechanical and
chemical, occurred with low intensity in ilmenite grain of the study area.
492 M. Sundararajan, K.H. Bhat, N. Babu, M.E.K. Janaki, P.N. Mohan Das Vol.8, No.6
The financial support by the CSIR, New Delhi under the Xth Five Year Plan Net work
programme is gratefully acknowledged. We thank the Director, NIIST Trivandrum for extending
the laboratory facilities.
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