NON-METALLIC AND REFRACTORY MINERALS GROUP T HE important minerals which fal! under this group are (1) Limestone (2) Magnesite (3) Dolomite, (4) Kyanite-Sillimanite (5) Quartz- Silica Sand, (C) Fluorspar and (7) Bentonite 1. LIMESTONE Limestone is the most mined and widely used industrial raw material next to coal and iron ore. It is used in the manufacture of cement, as flux in iron and steel industry and ferro-alloys and in fertilizer, chemical and paper industries and also as building material and ornamental stone. It occurs in all the States and distributed in most of the geological formations in India right from the pre-cambrian to recent. Reserves The total grade-wise reserves of all the limestone deposits are not fully known. G.S.I. has estimated them as around 17,952 million tonnes of inferred reserves. Some broad estimates of all grades in the different States according to the G.S.I. and other organisatios like I.B.M. State Directorates of Geology and Mining etc. are given in Table 1.31. The flux grade includes blast furnace grade and S.M.S. grade varieties. Specifications , Grades and Uses There are various specifications to which the limestone is to be met with to be used for different industries. In some cases the specifications are to be adhered to the chemical analysis (grade) as well as to the physical characteristics of the limestone such as hardeness, size etc. Limestone is most widely used in the manu- facture of portland cement and about 4 of the limestone produced in the country is being utilised for the cement industry. Cement grade limestone is to conform to the following specifications : °./o CaO :- __42 to 44% CaO 45.0 (Min) MgO :- 3.3 MgO 3.0 (Max. tolerable upto 5.0%). AI,O :- <4.5 ALO,; + SiO0_2 15.0-20.0 Fe.O:, :- <2.5 SiO, :- 14% Fe 2.0 (Max.) Total Carbonate :- 79-81% Pure limestone is neither necessary nor desirable. Pyrite and free silica should be absent, and alkalies low. Next to cement industry, limestone is used as a flux in iron and steel and ferro-manganese in- dustries. Blast furnace grade (B.F.G.) and open- hearth (S.M.S.) grade are the two common types used in iron and steel industry and are to con- form to the specifications given in the following page. 24
Transcript
NON-METALLIC AND REFRACTORY MINERALS GROUP
T HE important minerals which fal! under thisgroup are (1) Limestone (2) Magnesite
Limestone is the most mined and widely usedindustrial raw material next to coal and iron ore.It is used in the manufacture of cement, as fluxin iron and steel industry and ferro-alloys and infertilizer, chemical and paper industries and alsoas building material and ornamental stone. Itoccurs in all the States and distributed in most ofthe geological formations in India right from thepre-cambrian to recent.
Reserves
The total grade-wise reserves of all thelimestone deposits are not fully known. G.S.I. hasestimated them as around 17,952 million tonnesof inferred reserves. Some broad estimates ofall grades in the different States according to theG.S.I. and other organisatios like I.B.M. StateDirectorates of Geology and Mining etc. are givenin Table 1.31. The flux grade includes blastfurnace grade and S.M.S. grade varieties.
Specifications , Grades and Uses
There are various specifications to which the
limestone is to be met with to be used for differentindustries. In some cases the specifications areto be adhered to the chemical analysis (grade)as well as to the physical characteristics of thelimestone such as hardeness, size etc.
Limestone is most widely used in the manu-facture of portland cement and about 4 of thelimestone produced in the country is being utilisedfor the cement industry. Cement grade limestoneis to conform to the following specifications :
°./oCaO :- __42 to 44% CaO 45.0 (Min)MgO :- 3.3 MgO 3.0 (Max. tolerable
Pure limestone is neither necessary nor desirable.Pyrite and free silica should be absent, andalkalies low.
Next to cement industry, limestone is used as aflux in iron and steel and ferro-manganese in-dustries. Blast furnace grade (B.F.G.) and open-hearth (S.M.S.) grade are the two common typesused in iron and steel industry and are to con-form to the specifications given in the followingpage.
Maharashtra (12) 36.93 526.48 2735.92Manipur (14) - N. A. --- 3.0Orissa (15) 1.60 117.40 - 94.40Pondicherry (16) N.A. - 4.0
Rajasthan 18.06 (17) 50.00 251.33 37.46 5266.54Tamil Nadu (18) 2.34 6.00 - 295.45Uttar Pradesh 0.51 (19) 336 88 6.78 149.94Punjab (20) - N. A. - 1.83
Kerala (21) N.A. - 7.14West Beijal (22) N.A. -- -
(Source - I.B.M.) (1971).
The limestone should be of 5 to 10 cm in sizedense, massive compact and preferably finegrained and non-gritting on burning and shouldwithstand batch load of the operating furnace.
Limestone is used in fertilizer production intwo plants in India namely the Naya Nangal unitof FCI and Rourkela Unit of HSL. The NayaNangal uses both limestone and dolomite togetherhaving combined CaCO;,+MgCo.=90% Minimum
with CaC0 54--70% and MgCO.,=22-45%Si0.2 =4% (Max.) ; Moisture=0.5% (Max.)organic matter=0.5% (Max.) : S=Nil (free or assulphides). The size range desired of the lumpsis from 203 mm (8") with pieces upto 279 mm(11") in the long direction not to exceed 10%.
The Rourkela fertilizer plant uses limestonehaving insolubles 12% (Max.) and lump sizeranging from 3 to 25 mm.
25
Limestone is used in most of the chemical Future I-rendindustries such as calcium carbide manufacture,bleaching powder, soda ash, caustic soda etc. The demand for cement and iron and steel haveafter calcination in the form of lime (CaO), and risen steeply during the last 10 to 15 years andshould be originally of a high grade nature. The accordingly the requirements of limestone havefollowing are the specifications of lime for the also increased. The future requirements of lime-various chemical industries. stone for both cement and iron and steel in-
7. Paper : (for sulphite pulp manufacture) : CaO = 92.5% Min.MgO = 2.5% Max ; Fe„O.{+AI.,O,,+SiO„ = 3.0% (Max.)
Limestone of similar grade is used in the manu-facture of bleaching powder, caustic soda andsoda ash. It is also used for buildings and con-struction purposes.
Production , Domestic Consumption
Production of limestone as seen for the lastfew years is on the increase due to domesticdemand for the expanding cement and iron andsteel industries of the country. Madhya Pradeshtops the list among the various states producinglimestone. The production figures for the diffe-rent states are given in Table 1.32. The domesticconsumption of limestone in the various industriesis given in Table 1.33. Besides limestone, lime-kankar, lime shells and calcareous sea sand/marlare also used in the various above industries.
Import and Export
There was no import of limestone to India after1965. The export trend of limestone/lime for thelast few years is given in Table 1.34.
dustry are likely to increase further in the comingyears with the expansion programmes in boththese industries. As the reserves of high gradelimestone meant for iron and steel industry arelimited, the necessity is there now for conserva-tion and proper utilisation of the resources byproper development and expansion of the existingmines to the full capacity and by benefication ofof low grade limestone.
Attempts are also to be made to developsubstitute materials to be used for cement in-dustry in partial replacement of lime-stone withB.F. slags etc . to minimise the limestone usageand conserve the same.
The future requirements of limestone for internalconsumption as estimated by Planning Group onMinerals would be 38.3 million tonnes of cementgrade and 10.7 million tonnes of flux grade for1978-79. It is further estimated that it is likelyto touch 25.0 million tonnes of flux grade by1990-91.
26
^,1i ni s 1 MAIN NilNHdIINRN N illi # _.. +'"^"''^1"
T ^ ^^' ^ ^1f"" ?i""t^ T ^,"''T"^'^"I"'1^,^,^f^^^^,^,,,^"'^'^.,^.^^, ^,^^► ,^^^ ,^^^, ,:^,^...^,^,,,^..III
r
_
O)
I N
tO fo
M
IC)I "-I
My l N
2MM
M0
O)d r
rM
r W6)
d Cfl M_ N I 00 m -I GLD W V X) Q) d LO L N L M LO
0 Nr r N
WN o O a)
0 (r)I (0 W rZ N N N
dN
L6d
L6N N C^id °' I Ln I
N IWZ0
OcoLO
hLOr
0rl(D N
O)
n
MMO)
WLOL
Ln
O
MdLf)
WhLA
MNO
r-(D
Wr-Q)
dcoN
M Irlh
CO I
N
H N L CO Ln N M LO 0 N N LO Ln cp (V (n I cV IL co h (0 Q) M M d CD W m LD L h
W CON
W NN
It ItN
Lnd
mN N d LO
I NW N N a) N d M O O
DM m co CD
LL 0 co co It 0 co 0 'IT CO LO L() (D LO Cl) m0 O N M W O O L - W O CD LL7 M d W I h
O(D
r- r-- 0 CO coZ r
L co (D Wm
o(D d t W, r- ! LO 00 M a^d M pp
,co 0 co
N N N N d N N I I
N IMM
CD6)
rCfl
a CDL
rM
NN
rco
0m
6) co
N
NLO
d M M i N
00 h NU)
(D (0 M O d V r W r - cof
d0cc
CTm Cho
W N m OM I,
O^td
LD()7
LC)LD
NCO
MM
dM
h i Na L
-
N N
,
0 CD N WW I
N N N N MN
N II N
Q) LO d 0 LO O (o M 0 LO I
W(DO)
co6)
0r
rh
L NO C a t L N r
LOLo
r-m d r
Qco(0 o (m0 '* N a m U)
N m p a) m rn I NF- ^ Ln r L (C
(D °Nm
N N M M I
HM r co co N r 0 co r 0 Ln C,
N LLD It O) M O rNO
h LOM
Md
O)CD
OD 00Cl) CO
hW
o IN
W h r 6 06 4r-': m co CD N O) (p CO to, hJCo
WL co LO co co h It '. L N N Cl) r co
aI r 0 L d CO WM N M I rnI _
hd O M L!) r M N Lo I dm L) d O N O W C'4 0 co L L L a o
Cfl M N LO W O r O O . h
CO OCD m C4 -zt N co co L() C ) (5) I OtD CO M W O 6) M co CO O) O O M
LT
Nd CO CC) M
N r Nr-O 00
LI I ^
E L
IN R a t Q)a) L y R O y ^ f ^ I
m a) 0_ X 1O m a^_0 a l-be
C:
t`°Z
ma
ym
v
L Em cc
[O E C t COyN
fO0 E f0 N
N L 7 (a E E A (O c
oQ Q
N
m
U)
C7
V
X
Ln
2
(D r
Y
W Cn O
O
a-
a
(N
CD H
27
TABLE 1 . 33-DOMESTIC CONSUMPTION OFLIMESTONE ( IN TONNES)
Industry 1967 1968
(1) Cement 1,46,27,506 1,54,07,861(2) Iron & Steel 27,90.677 33,28.841(3) Chemical 6,41.675 8,95,655(4) Others 14,08,692 14,83,327
Total 1,94,68,550 2,11,15,684
(Source : I.B.M.)
TABLE 1 . 34-EXPORTS OF LIMESTONE/LIME(IN TONNES)
1967 1968 1969 1970 1971 1972 1973 1974
1,129 408 465 298 282 3 ,016 75,454 60,727
2. MAGNESITE AND DOLOMITE
Magnesite is widely used in the basic refractoryindustry, cements and flooring after calcination.It is also used as a raw material for magnesiumcompounds and metallic magnesium and inchemical industry. It has got a potential exportmarket.
Dolomite is now-a-days employed as a flux stonein blast furnaces, particularly in the making offerro-sillicon and ferro-manganese because itcarries very little of the silica or the manganeseinto the slag. Calcined dolomite and dolomiticlimestone are widely used in basic open-hearthand bessemer convertors in steel industry. It isalso used in refractory, glass, paper and otherindustries.
Both magnesite and dolomite occur in almostall the states in the country, and got widedistribution.
Reserves, Specifications and Uses
Magnesite occurs in Andhra Pradesh, Bihar,Gujarat, Jammu & Kashmir, Karnataka, Rajasthan,Tamil Nadu and Uttar Pradesh, the most importantdeposits lying in Bihar (Singhbhum), Tamil-Nadu(Salem), and Uttar Pradesh (Almora) respec-tively. The important deposits are given inTable 1.35.
28
The specifications and grades of magnesitediffer widely on the usage. It is chiefly used inrefractories industry for the manufacture of basicrefractory bricks after calcining to be used in theopen hearth, electric arc furnaces and hot metalmixers, soaking pits etc. in iron and steel industry,and in copper converters. It is an importantsource of magnesium metal and also used in manu-facture of special cements, chemicals, pharma-ceuticals and rubber industry.
I.S.I. Specifications
Light magnesium carbonate for rubber in-dustry - I.S. 1420-1959 states that the materialshould consist of hydrated basic magnesium car-bonate in the form of dry, fine, white powder freefrom gritty impurities and added substances andconform to the specifications given in Table 1.36.
Ref ractories
According to IS. 1749 1961 and IS. 1750-1961magnesite used for the manufacture of magnesitebricks and dead-burnt pea-magnesite should con-form to the specifications given in Table 1.37.The Indian manufacturers of lightly calcined anddead-burnt magnesite utilize magnesite with44-46% MgO and 2.6% SiO„ (max).
Production , Domestic Consumption and Export
Tamil Nadu accounts for more than 90% ofmagnesite production in the country followed byKarnataka, Rajasthan and U.P. The annual pro-duction figures are given in Table 1.38. Domesticconsumption of magnesite industry-wise is givenin Table 1.39.
Export Policy
Manganesite is outside the purview of the ex-port control order 1968 and is freely allowed tobe exported without any export licence. The ex-port figures of magnesite (mostly calcined) aregiven in Table 1.40.
Import Policy
Magnesite can be imported for refractory purposesfor export production only. The import figuresare given Table 1.41.
r.11 '"^'' I II ! llsI I
TABLE 1.35-MAGNESITE DEPOSITS DISTRIBUTION (IN MILLION TONNES)
State
(1) Bihar
(2) Tamil Nadu
(3) Uttar Pradesh
(4) Rajasthan
District Deposit Reserve extent Grade
Singhbhum Bhitardari
Salem Suramangalam
6.1 (Tale/Refractory(magnesite)
(upto 15 metres depth)
43.35 ll grade with 11.0(upto 30 mts. depth )
bmillion ton
Reserve of Magnesite in U.P. (GSI)
(recovera le reserve) refractory grade
Almora Et Pithorgar Agar Girechina 3.44 m. ton (IBM )(MgO%)38-43;
Dewaldhar 8 m. tons (IBM) 41-42%%Pungar Valley 12.19 m. tons (DGM) 40-42%Lahore Valley 2.54 m. ton (DGM) 41-43%
Tentative estimate by IG.S.I.
r DewalthalThat area
Kanada Masauli(a) Masauli
16.81 m. tonsGoul-3.34 m. tonsKholi-Amthal 11.35 m. tons
6.7 m. tons 9-45%(b) Dhapali(c) Kanda
35.20 m. tons11.88 m. tons 39-45%
Chamoli Pipal Koti
Ajmer Sarupa-Ghnaja
1 m. ton
1.5 (D.G.M.)
Source: I.B.M., G.S.I. State Directorates of Geology & Mining
TABLE 1 .36-I.S. 1420 -1959 SPECIFICATION FOR TABLE 1.37-I.S . 1749 AND 1750 -1961 SPECIFICATIONSLIGHT MAGNESIUM CARBONATE FOR RUBBER FOR REFRACTORIES FOR STEEL INDUSTRIES AND
INDUSTRY DEADBURNT PEA MAGNESITE
Chemical constituent % Assay Specific IS : 1749-1961 IS : 1750-1961R i M f i Dequ rements agnesite re ractor es ead-burnt
for steel plants per magnesiteSi0.. Not prescribedCaO 1.0 (Max.)MgO 40-43.5 (Min.) Tolerance on size 1.5% or Not prescribedFe and Al as oxides 0.1 1 mm whicheverChlorides (CI) 0.2 greaterSulphates (SO 0.2 (Max.)Mn 0.004 Chemical analysisLoss on Ignition (LOI) 58.0 (Max.)
SiO,% 5.5 max. 5.5 max.Ca0% 2.5 max. 2.5 max.MgO% 85 min. 85 min.Refractories underFuture Trend and Expansion
load 1550°C min. Not prescribedApparent porosity
With the growing iron and steel industry which % by volume 24 max. -do-is the main consumer of refractory grade magne- True specific
site, the present reserves position cannot be taken gravity 3.53 max. 3.53 max.
as very satisfactory. As such intensive explora-tion work for finding out newer deposits of suit-able grade is to be geared up besides utilisingthe low grade deposits after suitable beneficiationtreatments to reduce the silica content in themagnesite. Recent indication shows that thereexists a huge potentiality of magnesite in Almoraand Pithoragarh districts of U.P. However, thebeneficiation possibility of high SiO, magnesiteof Salem will have to be studied.
3. DOLOMITE
Even though inferior to magnesite for utilisationin refractory industry, dolomite has now a daysgained importance in view of its cheapness, aswell as its utilisation as fluxing agent in iron andsteel industry. It occurs in almost all the states
29
TABLE 1.38-STATEWISE PRODUCTION OF MAGNESITE (IN TONNES)
State 1967 1968 1969 1970 1971 1972 1973 1974 1975
tonnes (G.S.I. report) with all grade. Reservesof some important deposits have been indicated
Industry 1967 1968
(1) Calcination 2,23,277 2,40,714(2) Refractory including
iron and steel 1,27.803 1,20,116(3) Chemical 1.746 1.759(4) Fertilizer 1,483 1,500(5) Glass 321 389(6) Cement 320 320(7) Foundry 168 108(8) Abestos products 275 315(9) Others ( abrasives etc.) 163 211
(Source : 1.13,W)
except, Assam, Jammu & Kashmir, Kerala, TamilNadu, Punjab and the Union Territories. Orissaand Madhya Pradesh are the chief producingstates of dolomite.
in Table 1.42. Details of many other deposits arenot known.
The specifications vary with the uses to whichdolomite is put to. High purity dolomite is usedin iron and steel, refractory and glass industries.Calcined dolomite and dolomitic limestone areused as linings in different furnaces of iron andsteel, copper and lead smelting. Dolomite is alsoused as a flux for iron ores in blast furnace aswell as in open-hearth furnace (low-magnesialimestone), and steel melting shops. The otheruses are in paper industry, in lime mortars, andin less quantities in rubber, varnish & paints,tanneries and for soil conditioning and fillers withfertilizers and in the manufacture of magnesiummetal. The specifications of different grades ofdolomite are given in Table 1.43.
years is given in Table 1.44. Domestic consump-tion of dolomite for the various industries is givenin Table 1.45. Exports of dolomite in the years1972 and 1973 are 3,769 tonnes and 8,733 tonnesrespectively. Earlier to 1972 there is no exportof the mineral. No imports of dolomite havetaken place so far.
Future Outlook
With the phased increase and envisaged expan-sions in the coming five year plans of iron andsteel industry which is the main domestic con-sumer field of dolomite, the demand for moreoutput of the mineral is arising year by year and
warrants the exploratory programmes to beabreast to meet the recurring and increasingdemands of the industries.
4, FLUORSPAR
The mineral Fluorspar or Fluorite (CaF„) is themost important commercial source of elementalfluorine and is chiefly used as a fluxing agent inthe manufacture of steel and other alloys, alu-minium, in the smelting of gold, silver, copper,lead etc. and in the manufacture of hydrofluoricacid, synthetic cryolite, glasses, enamels refre-girents, insecticides etc. Lately it has beenused in the extraction of U ... from other isotopesof uranium. The present indigenous productionof the mineral is far too inadequate of our require-ments and is to be imported to some extent. Thepotential deposits of Ambadungar in Gujarat Stateand the new finds of Rajasthan and MadhyaPradesh are expected to improve the country'srequirements of the mineral.
Reserves , Specification and Uses
The most important deposits of fluorspar lie inGujarat State (Ambadungar-Baroda dist.), MadhyaPradesh State (Chandi Dungri-Durg district), andRajasthan (Mandokopal-Dungarpur dist); Chowkri-Chhapoli and Salwari in Sikar district) besidessome minor occurrences in the states of Bihar,J & K, Karnataka, Himachal Pradesh and Punjab.Known reserves are given in Table 1.46. Speci-fications of the fluorspar vary with the use towhich it is put in the various industries. Standardsfor the various industries are given in Table 1.47& 1.48.
TABLE 1.43-SPECIFICATION OF DIFFERENT GRADES OF DOLOMITE
Constituents Refractory grade (furnace lining)
MgCO;,%
Mg0%
Si02% 1.0% Max.
CaCO3 Remainder
CaO% 20-30
A120;,%
Fe2O3%
2.0 Max.
Flux grade Glass grade
High grade
20.0 Min. Dolomite with iron oxideless than 0.2%
2.0 Max.
29.0 Min.
1.0 Max.
1.0 Max.
Lime grade
28-46
54.72
Others3.0
31
TABLE 1.44-DOLOMITE PRODUCTION (STATE- WISE) (IN TONNES)
State 1967 1968 1969 1970 1971 1972 1973 1974 1975
Fluorspar is mainly used as flux in the alu-minium and steel industries besides foundries andsmelters, while large quantities of acid gradefluorspar are required for the production ofsynthetic cryolite and fluoro-chemicals. It is alsoused in small amounts in ceramic, glass, enamel,refrigerating, insecticides, preservatives, dyestuffsand other industries.
Production , Domestic Consumption andImport
Indigenous production of fluorspar is on the,
"I - -1
7-77-Tirl710111.1"o __7,
iTuP777"
increase year by year even though it would notbe sufficient to meet domestic consumption whichis to be balanced by imports. In fact 80% of ourinternal needs amounting to about 10,000 tonnesis imported during the year 1972. Production,consumption and import details of fluorspar aregiven in Table 1.49.
Future Outlook
Until 1965 fluorspar was mainly consumed bythe metallurgical industry in India; but pattern ofconsumption has since changed, and is expected
to be about 29,000 tonnes in 1973-74, which mayrise upto 75,000 tonnes in 1983-84 as an inevitableconsequence of the future expansion programmesis the core sector like steel, aluminium and othermetallurgical industries and chemical glass andceramic industries in the country. As such deve-lopment of the known resources on a prioritybasis and utilization of low grade ores by adopt-ing beneficiation methods is to be resorted forminimising the imports. Further, more reservesare to be established by intensive exploration pro-grammes in potential areas to improve the presentreserves position.
TABLE 1.48-FLUORSPAR SPECIFICATIONS FROM U.S. NATIONAL STOCK PILE p. 69 A & B
Note : * = Effective CaF2 is calculated by deducting 2f% from the contained CaF2 for each 1% SiO2.= CaF: may be 95% Min. provided the available CaF2 is calculated by deducting 4% from total for each 1% SiO2.
ri, =CaF2 may be 95% minimum provided CaCO3 is 1 % minimum and CaCO3 shall not be less than 1.5% for each 1 % thatthe CaF, is below 97%.
TABLE 1 . 49-PRODUCTION , CONSUMPTION AND IMPORT OF FLUORSPAR ( IN TONNES)
differ in crystal systems . They are all converted
to mullite on calcination , which is widely used ashigh temperature refractory material as furnacelinings in cement ceramics , glass and metallurgi-
cal industries besides being used in electrical
insulator industry , automobile spark plugs
porcelain etc . Raw Kyanite is used in the manu-facture of certain ceramic materials . The world
famous Lapsa Buru Kyanite deposits ofSinghbhum district , Bihar are one of the mostimportant high grade deposits from where themineral is exported to different countries of theworld.
Reserves , Specifications and Uses
Kyanite occurs in Andhra Pradesh, Bihar,
Maharastra, Karnataka, Orissa, Rajasthan and
West Bengal. Of these the deposits of Bihar inSinghbhum district are of considerable impor-tance in extent and grade. Workable deposits ofkyanite and kyanite-quartz rock are present inSinghbhum district where active production isseen as early as 1924.
The total measured indicated and inferredreserves have been assessed at 2.99 milliontonnes. The potentialities of the 67.4 milliontonnes of Kyanite-quartz rock of Singhbhumdistrict containing 30% Kyanite are yet to beconfirmed. The kyanite-sillimanite deposits ofDahegaon-Pimpalgaon area of Bhandara districtin Maharastra State are of considerable impor-tance and estimated to be 1.87 million tonnes.The details of Kyanite known reserves are givenin Table 1.50.
Kyanite is chiefly used as a refractory liningmaterial after calcination which transforms intomullite, in furnaces for glass. melting, non-ferrousmetals, ceramics and cement kilns, electricalinsulators etc. The specifications of kyanite usedby the different refractory units in the countryare given in Table 1.51.
The current U.S. National Stockpile PurchaseSpecifications (P-270) (29.2, 1960 ), for IndianKyanite or concentrates are given below :
34
(a) Chemical requirements: Assay % ( ignitedat 1000 °C for one hr.).
(b) Phycal requirements
(1) Lump material :- Natural kyanite orelectrically fused synthetic mullite not more than10% by weight shall pass a 12.5 mm (half-inchscreen and not more than 1% by weight shall passthe U.S. Standard sieve No. 60 (A.S.T.M.Designation E-11).
(2) Fine material :- Each lot of ore or con-centrate in natural condition as loaded intorailroad cars in the U.S.A. shall contain not morethan 5% by weight which shall be retained on a12.5 mm (i") screen and not more than 60% byweight shall pass the U.S. Standard sieveNo. 16 (A.S.T.M. Designation E-11).
(3) Calcined material :- The calcined materialafter crushing and screening shall contain notmore than 60% by weight which shall pass the
U.S. Standard sieve No. 100 (A.S.T.M. Designa-tion E-11). The grains of the calcined refractorymaterial shall be strong and suitable for themanufacture of refractory bricks and specialshaped products. These products shall pass thetests required under the procedures laid downfor sampling, inspection and testing.
(c) P.C.E. tests (Pyrometric cone equivalent).
Each lot shall have its pyrometric coneequivalent determined by the latest revision ofA.S.T.M. Designation C-24-56, Pyrometric ConeEquivalent (P.C.E.) of Refractory Material, or byalternate methods approved by the buyer. ThePCE shall be as follows for the four types.
Type - A B C DP.C.E. Cone No. 37 37 37 38
Production , Domestic Consumption andExport
The production of Kyanite is given in Table 1.52.The domestic consumption of kyanite is relativelysmall as compared to the production and thebulk of the production is being exported as exportof this mineral was decontrolled since 1960. Thedomestic consumption and export figures ofkyanite are given in Table 1.53.
TABLE 1.50 (a)- INVENTORY OF RESERVES OF KYANITE AS ON 1.1.1973
State District Area RESERVE ( In million tonnes) Source
Meas . Indict. Inf. Total
Bihar Singhbhum LapsaburuEr Kasidih
0.102 0.159 0261In Bihar out of 0.261 m. tonnes . 0.1098m.t. as of commercial high grade (above60% AI. 0:, and rest is unclassified.
IBM
Karnataka Chitradurga. Holalkere , - 0.4600 0.7899 DGM ErHassan It Holenarsipur , 0.2999 In Karnataka out of 0.7899 m. tonnes LesseeMysore. Koliegal talnus . 0.0300 0.30 m. t. is of commercial low grade
(AI. 03 -58 -60%) and rest in unclassi-fied.
Maharashtra Bhandara Dahegaon &Pimpalgaon
1.87 1.87In Maharashtra out of 1 . 87 m. tonnes0.103 m.t. contain Al, 03 above 60%0.177 m. tonnes contain Al_ 0350 to 60% and rest is below 50%
DGM EtM.M.C.Ltd.
Al. 03.
Orissa Dhenkanal Joradanali 0.02(upto
0.05(upto 15
0.07( Grade unclassified)
Lessee
7.5 m.depth)
m . depth)
Future outlook increased demand of kyar,ite for domestic con-sumption and for exports which is placed at 0.15
The total reserves of kyanite (indicated and million tonnes by 1980-81 it is necessary that theinferred) are put at 2.99 million tonnes. However, present reserves position must be improved byone of this reserve only about 2 lakh tonnes is of extensive exploration programme of new depositshigh grade lumpy ore. So the reserve position and by evaluation and utilisation of the huge lowis far from happy. In order to meet the grade kyanite-quartz deposits 67.4 million of
TABLE 1. 50 (b) RESERVES OF LOW GRADE KYANITE ORE AS ON 1.1.1975
State District Area Reserve ( in million tonnes ) Source
Meas. Indict Inf. Total
AndhraPradesh
Khammam Garibpeta
Nellore Malakonda
48.00 G.S.I.(Kyanite content 10 -12% by volume)
32.00 D.G.M(Average recovery of kyanite from theschist is about 24%)
Singhbhum district by adopting suitable bene-ficiation methods. The world renowned highgrade Lapsa Buru deposit is likely to be depletedin the next decade. The export policy needsmodification in allowing the export of calcinedproduct instead of raw kyanite.
36
'!+
Physical and chemical analysis Assay %
Fe,O3 TiO, MgO LOl PCESegar
Cone No.
6. SILLIMANITE ( AI2O#, SiO.)
Like kyanite and andalusite it is also analumino-silicate with different crystal form and isof similar ceramic and other refractory uses Itcan be used directly without calcination as well
as after calcination. On calcination sillimanitebecomes the high temperature refractory materialmullite which is chiefly used in glass, ceramicsand cement industries as furnace linings and inabrasive industries and asbestos products. Thecalcined raw sillimanite also can be used sincesillimanite has a very low expansion in volumeon heating. It is, however, not suitable for usein ferrous metallurgy as iron oxide attacks andcorrodes the alumina bricks. A part of sillimaniteproduction is consumed by indigenous refractorymanufactures while a considerable amount isbeing exported to foreign countries.
Reserves, Specifications and Uses
Sillimanite deposits of workable importance arepresent in Khasi Hills. Assam, Bastar and Sidhidistricts, Madhya Pradesh and in beach sands ofKerala coast, Manavalam Kuruchi, in Quilondistrict, Kerala. Deposits of minor importanceare reported from Andhra Pradesh (Eastand West Godavari, Kristna, Srikakulam andVisakhapatnam districts), Bihar (Gaya andHazaribagh dist.), Maharastra (Bhandara andNagpur districts), Karnataka (Mysore district),Orissa (Sambalpur and Sundargarh districts)and Tamil Nadu (Coimbatore and Kanyakumaridistricts).
All India reserves of sillimanite as estimatedby G.S.I. are given in Table 1.54. These excludethe beach sand resources of Kerala (13 m. ton)containing 5-6% Sillimanite
Sillimanite is used as a refractory material foruse in glass, cement, ceramics, chemical, elec-trical, enamelling, metal smelting and refining,coal carbonisation industries etc. It is also usedfor electrical insulators manufacture and automo-bile spark plug bodies.
The normal chemical analysis of sillimanitebricks made from natural sillimanite is :
The commercial value z)f sillimanite group ofminerals and their products (including kyaniteand andalusite) is assessed by conducting per-formance tests for determination of refractoriness(P.C.E. value), particle size, porosity, bulk density,crushing strength and dimensional changes,spalling etc. besides the chemical analysis.
The ISI has formulated specifications for (i)
silliminate refractories for glass melting tank
furnaces vide IS : 2044-1962 and (ii) natural silli-manite blocks for glass melting tank furnacesvide IS : 2045-1962.
Production , Domestic Consumption , Exportand Import
The production and exports and imports ofsillimanite are given in Table 1.55. There aremany units manufacturing refractories in thecountry using sillimanite. The important concernsare M/s. Kumardhubi Fireclay & Silica Works Ltd.,and Belpahar Refractories. The domestic con-sumption of sillimanite in 1968 was 3,573 tonnes
Future Outlook
The future demand of sillimanite by 1978-79 isput at 0.016 million tonnes. Current productionis around 3,000 4,000 tonnes as seen in table 55.The total estimated reserves excluding the beachsand deposits (of both the west and east coastswhich are yet to be computed) stand at 0.125million tonnes. The high grade reserves ofAssam are limited and as such this materialshould be exclusively used for indigenous require-ments. Further as the present known reservesare not very large in relation to the anticipatedrequirements to meet the domestic consumers aswell as for exports, all efforts should be putforward to undertake detailed exploration pro-grammes of proving new deposits so as toaugment and conserve the existing high gradereserves. Beach sand sillimanite, after properbonding into blocks and bricks is also to be putinto use to conserve the natural block sillimanitereserves.
7. QUARTZ AND SILICA SAND
Quartz, quartzite, sand stone, Silica sand, opal,agate, flint, chalcedony etc. are the many forms
37
TABLE 1 . 54-SILLIMANITE RESERVES IN INDIA ( IN MILLION TONNES)
State District Area Reserves Remarks
(1) Assam Khasi & Jaintia Hills Sonapahar 0.025 Within a depth of 6 metres.(2) Madhya Pradesh Sidhi Pipra 0.10 Within a depth of 10 metres.
TABLE 1 . 55-PRODUCTION EXPORTS AND IMPORTS OF SILLIMANITE ( IN TONNES)
degrees of purity or concentration. Pegmatitequartzite, quartzose rocks, felspar rocks (grani-
tes) sandstones and silica sand (river sands)
are the important and economic sources of the
mineral quartz. They occur in almost all theStates. Quartz and glass sand are used for glass,
ceramic, abrasive and refractory industries,
Silica sand is used for moulding purposes in
foundries.
Reserves , Specifications and Uses
The reserves of quartz, quartzite and glasssand are quite extensive and wide spread andhave not been fully estimated. Some details ofthe estimates given by G.S.I. and some StateDepartments of Geology and Mining are given inTable 1.56.
The specifications which are to be adhereddepend on the use. Thus different types of speci-fications are to be observed for use inglass, refractories, foundry industries etc.Quartz/quartzite/silica sand is mainly used forthe manufacture of silica refractories, glass,ceramics, abrasives and ferrosilicon. River sandis employed for stowing in colleries and mouldingsand for foundries. Quartzite and sand-stone areused for building construction. Quartz and flintpebbles are used as grinding media in ball mills.High grade quartzite lumps are used in blastfurnace to reduce the viscosity of blast furnaceslags during iron smelting. Perfectly transparentand flawless quartz crystals are used in wirelessindustry and optical glassess, prisms and lenses.Fine ground silica is used in cement and rubberindustries.
TABLE 1.57-1SI SPECIFICATION IS : 488-1953FOR GLASS SAND
Ingredients Grade I Grade II Grade III
SiO2% Min. 97.5 95 . 0 92.50Fe,O3% Max. 0.06 0 . 12 0.50Ti0% Max. 0.10 010 0 50Grain size : Remaining on IS
test sieve 1 mm (aperture1.000 microns) Nil Nil Nil
Remaining on IS test sieve 60(aperture 592 microns) % byweight Max. 1.0 1.0 10
Passing through IS test sieve12 (aperture 124 microns)% by weight 5.0 5.0 5.0
Moisture % Max. 5.0 5.0 5.0
Specification for Glass Sand
The ISI has formulated a specification for glasssand IS : 488-1953 given in Table 1 .57. Thespecification for glass sand for use in differentcoloured glasses issued by the society of glasstechnology , U.K. is given in Table 1.58.
Silica Refractories
Specifications for silica bricks manufacture inthe country used by different manufacturing con-cerns such as Kumardhubi Fire clay and SilicaRefractories Ltd., A.C .C. Katni Works , OrissaCements etc . Quartz , Quartzite , Silica sand etc.containing 97-98.6% SiO .,, 1.3% AI.,O_; Max; 0.4-0.6% Fe O with traces of CaO, MgO and TiOThe refractory plant of MISL specifies quartz with99% SiO , 0.5% AI,O, and 0 . 5°,) Fa 0 Max. TISCOuses quartzite with 98 . 66% SiO , and 0 .67-0.7%AlO in steel plant. Bhilai Steel Plant usesquartzite with 92 °1o SiO„ for viscosity control ofslag in the blast furnace operations.
Foundry Sand
The silica sand used for foundry moulding pur-poses must have high refractoriness to withstandhigh temperatures of pouring ranging from1000'C to 1600'C. Rajmahal Sands are widelyused for steel castings.
Ferro-silicon
For the manufacture of ferro-silicon MISL usedquartz/quartzite with 98.6% SiO and size of51.75 mm, while Indian Metals and FerroalloysLtd., consumed quartz/quartzite with 97% SiOand low alumina and size 15 mm to 80 mm.
TABLE 1 . 58-SPECIFICATION FOR COLOUREDGLASS SAND
Chemical analysis of sandsAssay %
Glass varietySiO)%Min.
Fe_O,%Max.
Ti0„%Max.
(1) Fine optical glass 99.0 0.008 0.08(2) High grade domestic and
decorative glass 99 . 0 0.02 0.05(3) General colourless glass-
wares including containers 98.5 0 .04 0.10(4) Indian glass wares 98.0 0 . 06 to AI,O;,-
0.22 1.22%max.
39
Production , Domestic Consumption and Export
Production of quartz/quartzite and silica sandare given in Table 1.59. Consumption of quartz/quartzite/silica sand/Moulding sand in variousindustries are given in Table 1.60. The exportsand imports of quartz sand including ground
quartz are given in Table 1.61. In recent yearsthe imports have been minimised.
Future Outlook
India is self-sufficient of glass sands require-ments. Glass, Ceramic, Refractory, Ferro-siliconand Abrasive manufacturing industries are theimportant consumers of quartz/silica sand whilefoundries use moulding sand. The manufactureis being stepped up to meet the increasing defenceof optical glass, a strategic material for defence,requirements. Quartz crystals required for usein electronic instrumentation are met by imports.Ferro-silicon of different grades is being manu-factured within the country by more than oneunit.
8. BENTONITE ( NaCaMg )O.AI0O:,. 5 SiO,.nH,O
Bentonite constitutes mainly of montmorillonitegroup of clay minerals and occurs in nature astwo types, namely, the swelling type (15-20 times)and the non-swelling type. The swelling type(Sodium base ) is used as binder in pelletisation
of iron ore fines, limestone, fluorspar, zinc con-centrates etc., as a drilling mud in oil well drillingand as a binder in foundry moulding sands. Thenon-swelling type (calcium base) is mainly usedin decolourising, filtering and catalysis in thepetroleum industry and as a binder in foundrymoulding sands. The commercial utilisation ofbentonite depends more on its physico-chemicalproperties such as base-exchange capacity,thixotropy, setting time, swelling index, pH etc.than on its chemical composition. Bentonite issupposed to have been formed due to the altera-tion of volcanic ash or tuff.
Reserves , Specifications and Uses
Bentonite chiefly occurs in the states ofGujarat, Jammu and Kashmir. Rajasthan and
TABLE 1.60-CONSUMPTION OF QUARTZ'SILICASAND / MOULDING SAND ( IN TONNES)
TOTAL 280.454 271.953 348.341 474,236 557,368 662.037 720,533 664,839 323.013
40
1,61,3241,59.7531.55,717
63,82238,78216.4366,296
6,02.130
1975
279,420
Bihar where some commercial exploitation of thedeposits is found. Some details of the reservesof bentonite available of the various deposits aregiven in Table 1.62.
In Bihar, bentonite occurs at Tinpahar andBakudih deposits in the Rajmahal hills of SanthalParganas district. The Bakudih deposit is esti-mated to have a minium of 100,000 tonnes. Biharbentonite shows poor physical properties (poorswelling characteristics) mainly due to the pre-sence of gypsum and exchangeable Ca-+, Mg-4The Gujarat deposits are mostly of non-swellingtype. Bentonites from Jammu and Kashmir arelow in iron and alumina and high in calcium, whichcan be converted to sodium base by suitabletreatment. Rajasthan deposits are the mostextensive and superior to other deposits of thedifferent States.
Specifications and Uses
The specifications of bentonite vary with theuse to which it is put to and its use is determinedby the original physical and chemical properties,which may be modified if possible in caseswherever it is felt necessary. The industry-wisespecifications are given in Table 1.63.
Bentonite is mainly used in foundries for bond-ing of moulding sands. It is also used as a basefor medicinal, cosmetic and phar-maceutical pre-parations (chemical industry), for oil drilling mudand oil-refining. A small quantity is consumedin paints, ceramics and cosmetics. Sodiumbentonite is widely used as binder in pelletisationof iron ore fines, limestone, fluorspar fines etc.
India's Production, consumption, export andimport of bentonite are given in Table 1.64Complete production and indigenous consump-
1. Green permeability 180-200%2. Moisture 0.2-3%3. Strength = 7 to 8 lbs. p.s.i.4. Min. 98% passed through 200 mesh
Sodium base bentonite powder . Good swelling 90% M in pH : 7
1. Colour to standard setting properly2. Swelling should be equal to standa«1,
1. Screen test 80%-200%2. Moisture - 10%3. Viscosity 7% Slurry
1. Moisture content = 12% Max. when dried to constantweight at 105 -110:C
2. Wet sieve analysis -200 Mesh. 2% Max.3. Viscosity measure by Stormer Viscometer at 600 r.p.mshould no be less han 15 c.p.4. Filtration loss should not be more than 20 c.c. in 30 minutesat 100 ps.i. Testing should be carried out according to theprocedure of the Amercan Petroleum Institute.
5. Drilling mud Oil India Ltd. 1. No size specification in any formDuliajan. Assam 2. Sieve analysis . 200 Mesh. 2.0% Max.
3. Moisture content -- 10% Max. measured by drying to constant
(Source : I.B.M.)
tion data is not available even though the majorusers of bentonite in the country are foundries.The demand for bentonite is likely to increase
42
wet, at 105-110 C.4. Base exchange capacity not less than 80 million ton equiva-
lents per 100 gm. (on oven dry basis).5. Viscosity-7.0% sunspension of bentonite in distilled water
stayed for a day should have a viscosity not less than 25Cen-Viscometer at 20% C.
further due to the top -priority of oil explorationactivity in the country besides the innumerablefoundries spread over through out the country.
