SCOPE OF VALUE ADDED EARNINGS IN THE
POTENTIAL CLAY MINERALS IN THE STATE
Characteristics of clays:
China clay, commercially known as kaolin, is naturally occurring primary clay formed by
weathering of felspars. It is a unique industrial mineral as it is chemically inert and does not swell
with addition of water. It is commercially valued because of its whiteness and fine particle size. It
is soft and non-abrasive; has low conductivity of heat & electricity.
Ball clays are sedimentary clays and used for the similar purposes like China clay but they vary
only in plasticity, china clay being less plastic. Ball clay is a highly plastic variety of kaolin
having high binding power, tensile strength and shrinkage ability. It is generally utilized after
mixing with non-plastic clay to impart the desired plasticity in pottery, porcelain and refractory
industries. It also helps in the preparation of glaze, enamels and for imparting a dense vitrified
body.
Introduction:
The word clay it self indicates towards a material which is generally white creamish in colour and
having finer particle size. Its physical charactertics, that influence commercial utility, include
brightness, glossing, abrasiveness and viscosity. Clays are being used in large number of
industries in crude as well as processed form. On the basis of the physical and refractory
properties, the clays have been classified into different categories. The important are - (1) Kaolin
(China clay), (2) Ball clay and (3) fire clay. Naturally occurring clays contain small amounts of
impurities in the form of rock fragments, hydrous oxides and colloidal materials. The clays are
isocheimal but not isostructural. They contain no exchangeable cations. The kaolin group of
minerals does not swell with the addition of water and alumina present in the clays does not form
isomorphous series with any other metallic compounds.
Fire clays also consist mainly of kaolinite with minor impurities of other clay minerals, quartz,
iron, titanium and alkali impurities. These clays are refractory clays associated with sedimentary
formations and capable of withstanding temperatures around 1700° C. Fire clays are either
aluminous or siliceous and usually burn buff and are found associated with coal seams and other
coarser sediments. Fire clays include both plastic and non plastic varieties. A good quality fire
clay should have 24 to 26% water of plasticity and shrinkage after firing should be with in 6 to 8
%.
Uses:
The china clay is used in both crude and processed forms. Crude china clay is used in cement
industry.
Ceramic industry accounts for a major share of processed form of china clay. Besides ceramics,
other industries which account for consumption in substantial quantities are paper, paint and
rubber for processed china clay and insecticides & refractories for crude china clay. The
consumption of china clay in India was 2,61,100 tonnes during 2000-2001. The broad
consumption pattern is as under:
Ceramic Industries
- 43%
- 22%
Insecticides
-10%
Paints
- 10%
Cement Industries
Refractory
-7%
Paper
-5%
Others including cosmetics, rubber, abrasive,
- 3%
Asbestos products, chemicals,drycell batteries, electricals, electrodes glass industries etc.
The ball clay consumption in the country during 2000-2001 was 1,68,200 tonnes mainly
consumed in the manufactures of sanitary ware, floor & wall tiles, electrical porcelain & semi
vitreous white wares to the extent of 35% in body composition. The broad consumption of ball
clay is as under:
Ceramic industry
-
98%
Refractory & abrasives
-
2%
Fire clays are mainly produced from Andhra Pradesh and Gujarat while smaller quantities have
also produced from M.P., Maharashtra, West Bengal and Rajasthan. Both plastic & non-plastic
fire clays are being used by the refractory industry.
Resources:
India possesses fairly large insitu reserves of china 'Clay which are of the order of 2,353 million
tonnes distributed mainly in Kerala, West Bengal, Rajasthan, Orissa, Karnataka and Jharkhand
contributing over 83% of the total all India insitu reserves. Total insitu reserves of ball clay in the
country are placed at 88.3 million tonnes, more than 71 % of which are in Andhra Pradesh,
followed by Rajasthan 28% and negligible quantity in Gujarat.
Following table is showing resource position of different clays in the country:
China Clay
Ball Clay
2353 M.T
88.3 M.T
The known recoverable reserves in Rajasthan of different clays viz. china clays, ball clays and
fire clays are placed at about 208 million tonnes, 35 million tonnes and 17.8 million tonnes,
respectively. However, additional reserves of 20 million tonnes of fire clay are available from
Barings, Palana and Gurha areas of district Bikaner. Location map is enclosed. Following table is
showing the resource position of different clays in Rajasthan:
China clay
Ball clay
Fire clay
208 M.T.
35 M.T.
37.8 M.T.
Occurrences in Rajasthan:
China Clay:
Rajasthan contributes about 35% of total production of china clay of the country. There are 56
mining leases for china clay in the state and about 2, 87,384 tonnes mineral was produced during
the year 2002-2003. The description of major deposits in the state is given below:
Bhilwara district:
Kotri & Jahajpur - Extensive good quality clay deposits are reported from Kotri & Jahajpur
area. These deposits are quite suitable for various ceramic products. In the clay, the silica ranges
from 46 to 54% & alumina ranges from 29-34%. Iron content is variable but not more than
1.12%. The firing characteristics showed white to creamish white colour at l400°C. The estimated
reserves of Kotri and Jahajpur areas are about 1.5 & 2.5 M.T., respectively.
Other small deposits in the district are near Bhadupur and Mangrop villages.
Chittaurgarh District:
Eral: Deposits occurs east of Chittaurgarh Fort. Clays are greyish white, fine-grained and fairly plastic. It
analyses Si02-58.35%, AI203-27.79%, Fe203-0.85%, Na20 & K2O-0.66% and LOI-9.6%. The reserves are
about 4.0 M. T.
Sawa: Fairly extensive deposit occurs near village Sawa, 20 km. south of Chittaurgarh. It is
greyish white, fires to buff colour and is moderately plastic and showing Si02-66.78%, AI20323.59%, Fe203-1.31 %, Na20 & K2O-1.33% and LOI-5.66%. The estimated reserve is about 6.0
M.T.
Other china clay deposits are located near Bansi, Badi Sadri, Bhagawanpura, Chingsi and white
clay near Kantharia, Binota and Samor villages.
Jaipur district:
Small china clay deposits are located near Jorda, Fetehpura, Buchara, Khelno, Kishorepura,
Sonarupa, Col and Jonpura villages.
Sawaimadhopur district:
Small occurrences/working of china clay are noticed near villages methasur, phalodi Reasena and
Basu.
Sikar district:
Small clay deposits are located near Mahawa and Purushottampura villages.
Jodhpur district:
Occurrences/working of low grade clay is reported from Jewaria, Jodhpur, Ramasani-Rampura
and Kheradia villages.
Udaipur district:
Karbariyon-ka-Guda : This deposit is located 7 km. ESE of Udaipur. The thickness of the clay
band is more than17 m. The inferred reserves are of the order of 3.99 million tonnes.
Small occurrences/workings were also noticed near Manak Chowk area of Bundi district,
Chawandia, Kirala, Kharda-ki-Dani, Jeoria, Rupanas, Kaproda etc.
villages of Pali district; Bararo, Sarolkhera villages of Kota district; near village Phagwara in N
agaur district; Goredang, Malia, Lugia area of Ajmer district; near villages Gunga, Nagurda of
Barmer district and near Girwari village of Jhunjhunu district.
In Nagaur district, while exploratory drilling for lignite, extensive deposits of clay were
encountered.
The districtwise No. of leases and production for last three years of china clay from Rajasthan are shown
below:
Ball Clay:
Occurrences in Rajasthan:
Rajasthan contributes about 40% of ball clay to the total country's production. There are 74
mining leases for ball clay in the state and about 792.850 thousand tonnes mineral was produced
during the year 2002-03. The description of the deposits found in the state is given below:Bikaner district:
Kolayat-Kotri-Gurha area: - Kolayat-Gurha belt extends from Kolayat in the south to Gurha in
the north over a distance of 15 km. There are three horizons of clay; the richest middle horizon
has five clay bands alternating with ferruginous sandstone, grits & siltstone. The clay bands are
1.5 to 4 m. in thickness. Two bands in the lower horizon are 1.5 to 2.5 m. in thickness. The upper
horizon has a single clay band varying from 2 m. to 6.5 m. in thickness. The clay is white, often
interlayered with impure clays, it is highly plastic, fine grained and composed mostly of kaolinite.
The water of plasticity is about 27.6%.
Chandi area: - The deposit occurs 1 km. north of Chandi village. The thickness of the clay band
varies from 1 to 8 m. Estimated reserves are 3 million tonnes. The PCE value of Orton cone is 3031 i.e. l650-1680°C. The water of plasticity is 27.6%, fires to cream colour.
Mudh area: - Mudh deposit lies NW of village Mudh, about 4.8 km. from Sri Kolayatji Railway
station. Clay is grayish white in colour, practically free from grit and is mainly kaolinite, fine
grained with good plasticity.
Water of plasticity is 27.6% and has a clay substance of 61.2% PCE values of Orton cone 3031i.e. 1650-1680°C, fires to a cream colour. The reserves at Mudh and Kotri are about 2 M.T.
Gurha area: - A clay deposit is located near village Gurha. The deposit is very extensive with an
average thickness of about 3 m. The estimated reserves are about 2 M.T. The clay is dull white in
colour, slakes in water readily and has a soapy hand feeling.
The other minor deposits in the district are found near villages Kharicharan, Nal, lndo-ka-Bala,
Suraj-kiDhanio etc.
Ball clay is also reported from Kharadi, Literia in Pali district; Chhor, Devikot, Kita, Manda in
Jaisalmer district; Mundwa, Sardena, Nimri Chandawatan & lndawar in Nagaur district.
The districtwise production of Ball clay for past 3 years is shown in the following table:-
Fire Clay:
Rajasthan contributes about 10% of fire clay to the total country's production. There are 10
mining leases for fire clay in the state and about 1173 tonnes clay was produced during the year
2002-03. A deposit wise detail in the state is given below.
Bikaner District:
Main occurrences are found at following localities:
Palana area: The fire clay is 0.60 to 0.90 metre thick occurring below the lignite at depths
varying from 39 to 76 metros. It is plastic in nature. The estimated reserves are about two million
tonnes. The fire clay occurring above the lignite seams is upto 2 m. thick, but this is of inferior
quality. It is blackish grey in colour having good slaking characteristics. The chemical assay is
Si02-39.24%, Al203 -25.40%, Fe203 -1.25% & LOI - 12.28%. Water of plasticity is 29, dry
shrinkage is 4%, buff white fairly vitrified, PCE of Orton cone 31.
Barsingsar area: In Barsingsar area, clay have been encountered in the boreholes drilled for
lignite exploration. It occurs with an average thickness of 0.5 metres to 0.8 metres at various
depths between 30 to120 m. The clay beds are found alternately with the lignite seams. A thick
bed of clay (about 10 m.) is also found as overburden on lignite seams at 10 m. depth from the
surface.
Den area: An extensive deposit of clay at village Deh, district Bikaner under the ball clay bed,
has been located during lignite investigation.
Gurha: The clay beds are about 1.5 to 3 m. in thickness, have been found above the lignite seam
at village Gurha. On an average, 0.3 m. thick clay horizon will be available during the mining of
lignite.
Alwar District:
Pharoti area: Clay occurs intercalated in steeply dipping quartzite near village Pharoti. It is soft,
light grey and fairly plastic. The deposit appears to be more extensive.
Baswagate area: It is a small deposit occurring near Rajgarh town. It is greyish white in colour
and slightly iron stained. Water of plasticity is 15.99%.
Clay deposits also occur at Anadpura, Kuncha, Lalgoan and Bigwada areas of Alwar district.
Jhunjhunu District:
Girwari area: The deposit is located about 2 km. SW of Girwari. In this area, brownish clay
occur having moderate plasticity and good verification characteristics. The deposit is small. The
fire clay reserves are estimated to be less then ten thousand tonnes.
Sawai Madhopur District:
Phalodi area: Clay occurring at Phalodi is plastic, brownish in colour. The average thickness of
the clay band is 1.5 m. The other deposits are located at Naranli and Tatwara. The deposits at
Bhatpura, Ghat, Ghadi & Nirapur are being mined for clay.
Barmer District:
Botia Clays: The deposit at Botia in district Barmer is fairly large with estimated reserves of
about 1.2 million tonnes.
The clay is soft and gritty and is grayish white in colour. It analyses to Si02 -59.68%, Al203 - 25.66%,
Fe203-1.17%, k2O& Na203 -0.36%, LO -9.98%. It is suitable for making fire clay insulation bricks,
sewer pipes etc.
Bhadres area: The clay band is about 1 m. thick and occurs 5 km. from village Bhadres. It is
suitable for refractory.
Nimla area: The clay is fine grained, occurring 1 km. south of this village. It is suitable for stone
ware and fire clay insulation bricks.
Bharatpur District:
In this district, fire clay occurs associated with red ochre near village Chhuntri and Vilong. The
clay is suitable for the production of stoneware and fire clay insulation bricks.
Mining Processing & Marketing:
China clay, Ball clay & Fire clay deposits worked in Rajasthan are mostly pocket type. Opencast
mining & Semi Mechanized mining is followed in most of the mines. The most common practice
is to sink trial pits for locating clay pockets or beds which are gradually enlarged into pits of
various dimensions. Clay and overburden are quarried in benches. In few mines, bulldozers and
excavators are used to remove the overburden which is then transported through
trucks/tractors/trailers.
Crude clay is normally processed out side the lease hold area. Almost all the china clay
consuming industries consume processed china clay except cement, insecticide and refractory.
Most of the china clay is being processed by the conventional method of levigation/ washing in
the country. In addition to above, hightech equipments such as Mozeley hydrocyclone seperator,
high intensity magnetic seperator for bleaching, spray drying and calcination are being
practicised. There is a need to use more sophisticated processing techniques like ultrafroth
flotation, cryofilter. The recovery percentage varies from 14% to 56%.
Processed kaolin is being marketed mostly in levigated and spray dried forms and a small
quantity in crude form under different trade names. Grading is primarily based on white
coloration and grit content.
Exports & imports position:
The world production of the kaolin in the year 2002-2003 was about 25 million tones. About 50
countries produce clay ranging from relatively low cost unprocessed common clays to processed
grades of kaolin. The principal producers of kaolin are :
Country
Contribution to world market
(Approx.)
U.S.A.
-
40%
U.K.
-
11%
Brazil
-
9%
Czech Republic
-
6%
China
-
4%
Korea Repulic, Turky, Mexico, 30%
Spain, Germany, France, India etc.
Almost half of the refind kaolin (about 13 million tonnes per annum) is produced from U.S.A.,
U.K. and Brazil.
An export from India is only 8462 tonnes in the year 2000-2001 to Bangladesh (59%), Ethiopia
(9%), Philippines (8%), Sri Lanka & Nepal (5% each). India imported 6671 tonnes of clay from
U.S.A. (51 %), Brazil (19%), U.K. (9%), China (7%) & Germany (6%) during the same year.
Scope:
The state of Rajasthan has abundant resources of kaolin in Bikaner, Bhilwara, Chittaurgarh,
Nagaur, Pali and Barmer districts besides other smaller deposits all over the state. But looking
towards our production of 0.2 million tonnes against world production of 25 million tonnes per
annum, entrepreneurs should come forward to exploit the deposits and augment the exploitation
of the available deposits to increase our share in the world trade. The future requirement of
processed kaolin in the domestic market is expected to increase substantially. Most of the
processing of kaolin in the country is done by conventional methods like levigation and washing.
But hi-tech processing techniques will be necessary for acceleration of processed kaolin quantity.
New capacities for processing have to be established and existing capacities are to be augumented
in the country. Efforts are to be made to capture the potential foreign markets like of Egypt,
Zimbabwe, Iran, Malaysia, England and Pakistan. Exports to the traditional neighboring markets
like Bangladesh, Sri Lanka & Nepal and other markets like Kenya, U.A.E., Saudi Arabia,
Bulgaria, Bahrain and Ethiopia also be increased to fetch the foreign currency. There is every
scope of value added earnings in the potential clay resources in the Rajasthan.
A policy of granting the kaoline mining leases over lignite bearing areas, agriculture lands and
Govt. pastsure lands be considered. The deposits should be explored properly by drilling
irrespective of land title. The proved areas be declared as the "mining lands" after payment of
compensation to respective panchayats to the land holders, so that unnecessary delays in grant of
leases can be minimized.