BARYTES IN RAJASTHAN
Introduction
The name "baryte" (BaS04) is derived from the Greek term 'Barys', meaning heavy.
Barytes crystals are transparent to opaque, often occurs in stained brown, pink and grey
colour. Barytes theoretically contains 65.7% BaO and 34.3% SO3, has a specific gravity
of 4.5 and hardness 3 on Moh's scale. It is insoluble in water and comparatively
unaffected by acids which gives it added advantage in the preparation of drilling mud.
.
It is the chief ore mineral of barium, contains 58.8% barium and 41.2% sulphate.
Barytes occurs in assorted colours, although shades of dark grey and black are common
in commercial deposits. Generally it is found as irregular masses, concretions, nodules,
rosette-like, aggregates and in massive form to laminated beds. It is mostly associted
with quartz, chert, jasper, calcite, dolomite, siderite, celestite, fluorite and various
sulphide minerales (pyrite, chalcopyrite, galena, sphalerite and their oxidation
products).
Geologically, barytes deposits are found in rocks ranging from Archaean crystalline to
late Tertiary sediments. There are four types of occurrences (i) Vein deposits (ii) Residual
deposits, (iii) Bedded deposits and (iv) Replacement deposits.
India occupies a very prominent position in the world map of barytes, ranking second in
production and third in reserves. In the country barytes is extensively mined in Cuddpah
and Khamman districts of Andhra Pradesh. It is also mined in Alwar and Udaipur
districts of Rajasthan, Sirmur district of Himachal Pradesh and Gadehiroli district of
Maharashtra.
Occurrences in Rajasthan
Rajasthan is an important barytes producing state in India and Stands 2nd after Andhra
Pradesh. There are 9 mining leases for Barytes in the state and about 3727 tonnes was
produced during the year 1998-99. The description of the deposits in Rajasthan is given
below.
Alwar district
The most important and economically viable area in state is Alwar district. In this district
the barytes deposits fall in two distinct zones, one passing from Bhagat-ka-Bas and the
other Sainpuri to Akbarpur. These zones are commonly known as Rajgarh and Alwar
belts. In Rajgarh belt barytes deposits are located at number of places in the quartzites at
the contact of granite. The barytes occurrences in this area in general are along the shear
planes & fold closures in the form of veins and veinlets.
A brief description of the deposits falling in these two belts as well as other occurrences
is given below.
(A) Rajgarh Belt
(i) Khora-Makrora :- In Khora Makrora area litho units belongs to the upper part of
Alwar Group, comprising grity/arkosic quartzite, quartzite interbedded with shaly
phyllites and massive quartzites. Generally the barytes mineralisation in the area is
restricted to the arenaceous formations of Delhi Group. The host rock for barytes
mineralisation is quartzites with intercalation of phyllites. The barytes mineralisation
occurs as fissure filling within the Alwar quartzite. The barytes occurs as veins, veinlets
and stringers of limited length. The individual veins are seldom more than few meters in
length, though cummulative strike length sometimes may exceed even 50m. The
thickness of veins varies from 5cm to 2.2m The barytes from these veins are recovered
by under ground mining.
Chemical analysis of the barytes shows following result: BaS04 - 95.86%, BaO 62.92%, SiO2-2.34%, Fe2O3 0.12%, SrO-0.06%, Al203-0.48%, CaO - 0.39%
MgO-0.32%, LOI - 0.4%, sp.gr. 4.50.
(ii) Bhagat-ka-Bas :- Bhagat-ka-Bas area consists of two isolated hillocks surrounded
by flat ground near Babeli and Bhagat-ka-Bas villages. The rock units exposed in the
area are quartz-sericite-schist/phyllite interbedded with quartzite. The host rock for
barytes mineralisation is quartz-sericite schist and the barytes veins follow the bedding
and foliation plane. The barytes veins vary in thickness from 0.3 to 1.0 mt. Barytes
recovered from these veins is massive and white, light grey to pink in colour. The veins
are not exclusively of barytes mineral but quartz is also very much associated with it.
The area is being mined intermitently. The mining activity in Bhagat-ka-Bas area has
proved the persistence of barytes to a considerable depth (beyond 70mt. vertical depth).
(iii) Jamerauli Deposit:- The deposit is located about 0.5 km SE of Jamerauli village.
Barytes occurs as fissures, veins and veinlets along beddding planes, fractures joints &
fault zones. The mineralisation is essentially in quartzite along the north western slope of
the hill. The thickness of the vein varies from 1m to 3mt.
(iv) Ferozpur :- Just north of Madhogarh village, barytes occurs in the form of
veins/veinlets and stringers confined to 3 to 5 mt. wide N-S trending fault breccia zone
within felspathic quartzite. The brecciated zone is traceable for 200m but barytes
mineralisation in the form of veins and veinlets is confined only for 75mt. The exposed
average width of the barytes vein vary between 5 cm to 20 cm. Barytes is crystalline buff
and white coloured, analysis shows 88-92% BaS04 contents.
Apart from above some more small occurrences were noticed near village Kher,
Ramsinghpura, Jhatra Dholera, Goarah Gujor, Mundia, Balpur, Sainthal, Ladia Gujar,
Barli, Paplur.
(B) Alwar belt
(i) Jhandoli : Barytes deposit is located 26 km. NE of Alwar. The area comprises Alwar
quartzites & sericite schist. Barytes as veins and veinlets mostly occur along joints. One
important vein of about a metre thick exposed over a distance of 250 mt., probably
follows a shear zones. Float/talus are on western foot of the hill has also been worked at 5
places. Talus of barytes contains pebbles ranging from 1.5 cm to 4.5 cm in size and are
found over a length of 1050 mt. upto average depth of 1.5 mt. It is buff to white in colour,
analysis results shows BaSO4 content from 92 to 96%.
(ii) Bankhera : The deposit is located at a distance of 6 km. from Alwar town on AlwarJaipur Road. Barytes mineralisation is in sericite-quartz schist, which forms a part of
Alwar Group of Delhi Supergroup. It consists of two major veins of barytes, 85 mt. &
27mt. long respectively separated by 36mt. thick quartzite. Thickness of veins vary from
0.3 to 0.9 mt. The barytes is of pink colour and massive in nature.
(iii) Sainpuri Deposit : The deposit is located about 1 km. SE of this village. The
main barytes vein is associted with quartz biotite-chlorite schist of Alwar Group.
The vein is 50mt. long and 6 mt. wide. The associated minerals are quartz, chalcocite
& cuprite. Barytes is fine grained and colour varies from white to greyish white and
cryslalline in nature. The chemical analysis of the barytes show BaSO4 97.5%, Si02
- 0.14%, Iron oxide 0.74%, Al203 - 0.10% CaO 0.2%, MgO - 0.15%, alkalies etc.
0.14%.
A few more small barytes areas located due north and south of Alwar namely Bhurasid,
DholiDhoop, Ravan Dera, Umran, Karoli, Zehir-Ka-Khera, Bhurari Rata, Naurangabad,
Gatri etc. where the rock types exposed in the region are quartzite, sericite quartz schist,
phyllite hornblende quartz schist, quartz chlorite biotite schist. The barytes occurs along
with the fractured and jointed planes of quartzite and sericite quartz schist.
Udaipur District
(i) Relpataliya deposit: This deposit is the biggest deposit in state, located near
village Relpataliya 7 km. NW of Jagat in Udaipur district. The barytes occurs as a
long band in granitized gneisses and schist, flanked by metabasites on both hangig
and footwall sides. The barytes bearing zones could be traced over a strike length of
about 2.5 km. The main barytes band starts about 1.4 km. south of Relpataliya
village and continues in north east for a strike length of about 0.2 km. making a total
of 1.6 km. length. Besides this main zone, there are two more bands of barytes which
also follow the general trend of barytes mineralisation. These veins have a strike
length varying from 150 mt. to a maximum of 450mt.
The barytes veins occur in prominent low lying ridges and can well be identified with its
peculiar physical out look in contrast to other associated geological formation. The
barytes occur chiefly in two modes.
One is massive type deposit and the other type is represented by small veins and veinlets
in the host rocks forming a mixed zone of barytes zone and country rocks. The width of
barytes zone in general varies from half a mt. to about 5 mt. exceptionally reaching to 8
mt. At most of the places the barytes is massive in nature and medium to coarse grained.
White, off white and pink colour barytes has been found in the area. The analytical result
reveal that barytes contains BaO : 51-61%, S03 : 26 to 32%, Si02 : 5-12%, sp.gr. : 3.854.55%, BaS04 : 78-94%.
(ii) Babarmal : Barytes mineralisation is found over a strike length of about 6.5 km in
the form of disconnected thin lenses. It is associated with quartz veins intruded in the
granite gneisses. The thickness of the barytes veins varies from 10 cm to 40 cm. Small
veins of baryte occur near Tikhi Chanda and Kharwa villages.
Rajsamand district
Delwara-Nathdwara belt
In this area the barytes occurs mainly as fissure and breccia or replacement in limestone.
The mineralisation is mostly confined to the chlorite schist and occurs as enechelon veins
along foliation planes. The barytes deposits / occurrences of this belt are found in Gurli,
Kioli, Junagarh, Laxmi Guda, Barwallia, Pipalwas, Nerach, Khetrapal-ka-Gudha,
Kagmadar, Nagaria, Ramela, Ghora Ghati and Keroli localities.
The description of some important areas is given below:
(i) Gurli deposit: A thin vein of barytes about 25 mt. long and 5 cm to 30 cm wide
occurs about 900 mt. NE of Gurli. The country rocks are biotite-chlorite-schist grading
into phyllites and grey quartzite.
The barytes is milky white to greyish white in colour, fine grained, massive and forms
more than 60% of the veins.
(ii) Kioli Deposit: About 250 mt. NNE of Kioli, thin veins of barytes crop out in the
plain ground within the chlorite schist. The veins are intruded along the folliation plane.
These veins can be traced south-west ward along strike intermittently for a distance of
about 100 mt. within a zone of about 5 mt. The individual veins are about 1.20 mt., 20
cm. and 30 cm. in width respectively.
(iii) Junagarh deposit: Thin streak, lenses and pockets of barytes occur within the
dolomite marble band near Junagarh. The dolomite band runs from 1 km. west of Kioli to
south-west of Lambi, but the barytes is seen to occur impersistently only from near
Junagarh to 600 mt. east of Dulwatan-Ka-Gurha. Near Junagarh, it occurs as thin lenticles
within the marble, but east of Dulwaton Ka Gurha, it occurs at the contact of the quartz
vein and the dolomite. The barytes bearing zone runs impersistently for a distance of
about 50 mt. along strike and veins in width from 25 cm. to one mt. The individual lens
however does not exceed for more than 5 mt. along strike. The barytes is milky white to
greyish white, hard, compact, heavy and massive. It is fine to medium grained and
occassionally coarsed grained. It contains intercalation of dolomite and vein quartz.
Bundi district
The barytes occurs in the form of veins associated with quartz intruding the dolomitic
limestone or at the contact of limestone and phyllites near Umar village in Bundi district.
Generally it follows the fissures and fracture planes. In the Pagara area barytes veins are
located just south of village in the prominent quartz veins running along fault. There are
two barytes veins one is about 1.5 mt. wide and 8 mt.long. These barytes veins do not
persist beyond 13 mt. in depth. The barytes is white and greyish and is found associated
with galena, cerusite, malachite and azurite. Barytes appeass to have formed by the
replacement of limestone at the contact with the schist.
Bharatpur district
In Bharatpur district, barytes occurs, in rocks of Delhi Supergroup. Deposits are closely
associated with post Delhi basic intrusives and occur at Hatori, Ghatri and Karwar
villages.
Hatori Deposit: The exposurs are noticed at a number of places in the west and north of
Hatori village. The barytes vein occur as lenticular fissure fillings in quartzites. The
veins are irregular and extend over a length of nearly 14 mt. Baryte is associated with
chalcopyrite, pyrite and quartz.
. Ghatri Deposit: Barytes occurs on the southern flank of a small hill about 1.75 km.
WNW of Ghatri village.
Mineralisation is confined to NNE-SSW trending vertical to steeply dipping 1 mt. to
15 mt. wide zone and a few cm to 30 cm. in thickness.
Chittorgarh district
In this district barytes is reported from Jaura Kalan area near Rawat Bhata in the upper
Vindhyan sediment. It occurs as small veins stringers, fillings and lamination in the
shales of upper Vindhyan age.
Bhilwara district
Near village Barliyas barytes is found associated with quartz and calcite veins which are
intruded in the decomposed granite-gneisses of Pre-Aravalli age. Thickness of the vein
varies from 2 cm. to 2 m. and extends about 15 m. in north-west direction. Barytes is grey
and buff in colour. Malachite and small cubes of galena also occur in the quartz-barytescalcite veins. The deposit has been worked to a depth of 11 mt. but due to low grade,
mining work has been suspended.
Pali district
The veins of barytes have been worked at number of places in Punagarh hill, about 9 km.
west of Pali. There are 16 lenses of brecciated quartz-barytes haematite rocks and these
vary in size from 30 cm to 50 cms. in the width and up to 450 mt. in length. Veins and
veinlets of barytes varying in size from 5 cm. to 1 mt. in thickness occur in these lenses
or at the contact with slates. The barytes is pink, bright grey in colour and mostly
massive. The mining work is suspended due to low grade of barytes.
Sikar district
The deposits are located about 2 km. NE and SSW of the village Khaiagbingpur and
Naroda. Barytes is found as fissure filling in weak zones trending in NS direction along
bedding planes and is associated with calc-schist of Ajabgarh Group of Delhi
Supergroup. There are two veins of barytes with 1 to 2.5 mt. partings and are traceable
for a strike length of about 80 mts. The area was previously mined both by open cast and
underground method, but due to the ground water problem, the mines are closed.
Jalor district
The barytes mineralisation is present in the southwestern and southern parts of the area of
fluorite mineralisation. The barytes veins are occupying the fractures and are generally
present across the fluorite vein but at some places like Santoshi hill, Lal hill, Malinath
hill and Tavidar hill barytes occurs in association with the fluorite veins.
Reserves
The all India total insitu reserves of barytes are 82,806'944 tonnes out of which
recoverable reserves is 70,146,559 tonnes. A.P. is the major producer of barytes having
total recoverable reserves of 67,053, 540tonnes (95.5%) followed by Rajasthan 2,357,737
tonnes (3.36%). In Alwar district the total recoverable reserves estimated in leasehold
area are 751,452 tonnes and 9,075 tonnes in free hold areas. In Bharatpur district, the
total recoverable reserves are 1,260 tonnes in free hold area. In Bhilwara district, the total
recoverable reserves are 1,294 tonnes in free hold area. In Bundi district the total
recoverable reserves are 15,954 tonnes in free hold area. In Pali district the total
recoverable reserves of 2,144 tonnes are in free hold area. In Sikar district the total
recoverable reserves of 40,793 tonnes are estimated in lease hold area. In Udaipur district
the total recoverable reserves of 1,526,160 tonnes are estimated in lease hold area and
9,600 tonnes in free hold area.
Industrial Application
Barytes after suitable grinding and pulverizing, has many uses. It is mainly used in oil
well drilling and it is estimated that 90 percent of the barytes produced in the world is
used only for drilling purposes. It is also found useful in the manufacture of white
pigment or extender in pigments and barium chemicals, in the glass industry and as filler
in rubber, leather, textile and paper goods.
Oil well
For the preparation of drilling mud, barytes of finer mesh (325 BSS) is usually required.
Finely powdered barytes is mixed in suitable proportions with colloidal clay, like
bentonite and water to make a drilling mud.
Drilling mud in general serves several purposes: it lubricates and cools the bit, plasters
the walls of the drill hole to prevent caving, carries the cuttings up the well to the surface
and counter acts the high gas and oil pressures to their formations level to prevent
outburst. It is estimated that for every 300 metres of high pressures well drilled, about 5
tonnes of barytes are required. This figure is variable depending upon the quantity of
colloidal clay used, pressure of the gas and the depth of the well. Thus the requirements
of barytes are placed as high as 10 tonnes per 300 metres drilling.
Paint
Barytes is an important raw material for the manufacture of lithophone, a white pigment
used in paints. In India, barytes is entirely used in the pulverized form (300 mesh) as an
extender in paint manufacture. There are many units manufacturing enamel paints for
ceramic glazes. For enamel paints generally, precipitated barium sulphate is used. Paint
manufacturers prefer snow-white or white barytes. Off-colour barytes is used as an
extender in dark paints.
Lithophone is an intimate mixture of two precipitated salts, ZnS and BaS04. In the
manufacture of lithophone, the colour of the barytes is not regarded as deleterious
provided the staining is superficial. Such colouration of barytes is leached out by dilute
hydro-chloric or sulphuric acids. Removal of the colour becomes difficult in the case of
minute crystalline barytes. Where the barytes has become stained due to manganese and
iron oxide, colouration is removed by reasting the mineral with nitre and salt and then
leaching with sulphuric acid.
Rubber
The rubber industry is an importgnt consumer. Pulverized barytes of 250 to 300 mesh is
added to the rubber compouned for reinforcement and as filler. All the important
producers of rubber goods in the country consume barytes in small quantities for
reinforcement purposes.
Chemicals
In the manufacture of various barium chemicals, the compound barium sulphide (BaS) is
taken as a starting point. Barium sulphide is obtained by reducing barytes in a
reverberatory furnace. BaS is readily soluble in hot water and dissolves to form barium
hydroxide, [Ba(OH)2] and barium disulphide BaHS2.
Blanc-fixe (precipitated barium sulphate) is used as a fine white pigment filler in paints,
rubber, goods, linoleum, oil cloth and some grades of paper, specially photographic.
Precipitated barium carbonate is used in the ceramic industry to prevent the development
of scum on wares. It reduces porosity, prevents decolouration in bricks and is also used in
making crown and flint less glasses.
Specifications
Drilling Mud
In the preparation of drilling mud, barytes containing a minimum of 94 percent BaS04 of
a specific gravity of 4.15 is preferred. It must be of fine sieve over 300 mesh and its
solubility in water should be absolutely minimum. The colour of the barytes and a small
percentage of silica or iron oxide are not regarded objectionable. It should however be
free from clayey material as it lowers the specific gravity. Indian Standard Specitications
(IS: 2881-1964) lays down the following properties in barytes for the preparation of
drilling mud.
BaSO4
94 percent min.
Fines
Material retained on 53-micron IS. Sieve must not be more than 2
percent
Specific Gravity
4.15 min.
Solubility
Solubility in water at 20 degree not more than 0.02 percent
Colour
Grey white
Foreign importers, especially those from the Middle East countries, prefer barytes
powder having a minimum sp. gr. of 4.2 bagged in hessian cloth.
Lithophone and paint
For the manufacture of pigment, manufactures prefer snow white barytes containing a
minimum of 95 percent BaS04. It should be free from mud, clay or siliceous minerals.
Silicates are on the whole less deleterious than free silica as it tends to form barium
silicate, which may occlude barytes. The presence of iron oxide is undesirable. A
maximum of 1 percent of Fe203 is allowed. The presence of iron oxide, clay, silica, etc.
often flux at temperatures below 1300oC, the furnace temperature usually employed for
reducing barytes to the sulphide with coal or coke. It is estimated that 1 percent of iron
oxide may render 4 percent of barium sulphide inactive. Some compounds of iron or
manganese are regarded harmful. The presence of galena upto 3 percent does not affect
the reduction of BaSO4 to BaS in the furnace but fluorspar is objectionable as it corrodes
furnace lining.
Indian consumers prefer to accept barytes in a pulverized form of 300 mesh for use as an
extender in paint manufacture. One of important consumer prescribes that snow-white
barytes should be absolutely free from carbonates. Moisture must not exceed 0.1 percent
and coarse particles on 240 mesh are not to exceed 0.02 percent.
The Indian Standard Specifications for barytes for paints (IS: 64-1950) specifies that the
material should contain not less than 95 percent BaSO4 carbonates not exceeding 0.5
percent expressed as CO2 and that the material should be supplied as a dry powder. When
lead-free material is required, it should contain not more than 0.05 percent of lead or
compounds of lead. The volatile matter should not exceed 0.05 percent: residue on sieve
(BSS 240 mesh) not more than 0.25 percent; oil absorption not less than 6 percent and
not more than 12 percent and colour not inferior to the approved sample. Water soluble
matter should not be more than 0.5 percent.
Chemical manufacture
The specification of barytes required for manufacture of chemicals and various
compounds, is the same as that of lithophone. As mentioned earlier BaS is the starting
point for the production of various chemicals. As such, all the impurities present in
barytes which are regarded undesirable and deleterious for chemical manufacture are the
same as indicated under lithophone.
Glass
Glass manufacturers usually required barytes containing minimum of 98 percent BaS04
and a maximum of 1.5 percent Si02, 0.165 percent Al203 and 0.15 percent Fe203 In mesh
size a mixture ranging from 30 mesh down through 140 is preferred. Iron is the most
undesirable impurity.
Rubber and paper
Specifications for barytes used as a filler or in aggregate are not so strict as those for
chemicals; in most cases mesh size is considered important. In recent times, paper and
rubber manufacturers have been insisting upon barytes containing a minimum of 99.5
percent BaS04. Barytes of such purity is generally not found in nature; hence, bleached
barytes or blanc-fixe (ppt. BaSO4) is preferred.
Other uses : It is used as the chief constituent of plaster in X-ray laboratories to protect
the operators from harmful radiations. Metallic barium is used in certain types of
electronic tubes.
Statistical Information for Barytes in Rajasthan
Year
Production
(thos. Rs.)
4.950
3.250
2.769
6.461
3.727
1994-95
1995-96
1996-97
1997-98
1998-99
Sale Value
(thos. Rs.)
1553.00
2106.00
1615.00
6532.90
3706.00
Revenue
(thos. Rs.)
284.00
170.00
131.27
393.13
258.94
No. of leases
10
11
11
11
9
District wise production of Barytes (Year: 1998-99)
S.No.
(1)
(2)
(3)
(4)
District
Udaipur
Alwar
Rajsamand
Sikar
Production
(thos. tons)
3.365
0.341
0.021
-
Leases
1
4
3
1