Mineral Resources Other Than Hydrocarbon

Mineral Resources other than Hydrocarbon

1.COAL

The existence of coal deposits in Upper Assam had been known from the early days of the British occupation of the State. It is mentioned in the old Gazetteer of Lakhimpur that in 1825,Lieutenant Wilock reported that coal was found near Borhat on the Disang river. In 1825,about 5000 maundsof coal were quarried by Mr.Bruce was dispatched to Calcutta. The Coal was pronounced to be equal to English coal and the best ever found in India. But it took time to develop this industry. A geological survey of coal fields was undertaken by Mr. Medlicott in 1864-65. In 1876,Mr.Mallet who examined the coal fields of Nagaland, divided the coal measures of Lakhimpur into two fields, Makum and Jaipur. According to him, Makum coal field contained about eighteen million tons of coals, about half of which could be exploited

In Assam, the coal reserves have been estimated as follows:

Proved reserves – 259 Million Ton
Indicated reserves – 27 Million Ton
Inferred reserves – 34 Million Ton

Coal Field-wise deposit of Coal is given below:

Coal Deposit in Assam

1.Coal Deposit at Dilli – Jeypore (Dibrugarh & Sivasagar District)

Coal
Deposit (s) / Description of deposit
Quality / Reserve (million ton) / Specific features
Dilli – Jeypore
(Dibrugarh & Sivasagar District) / Ash % - 4.7 0 – 21.30
Moisture % - 3.1 – 21.4
Volatile Matter % 35.0 – 42.50
Total Sulphur – 1.31- 6.62
As an average the form of Sulphur content in Makum coal field is as below:
Organic Sulphur - > 80%
Pyritic sulphur - < 17 %
SulphateSulphur - < 12%
CV Kcal/kg – 5730 – 7706
The Petrographical analysis of Makum coal in % by volume is given below:
Vitrinite – 90
Exinite – 4.8
Inertinite – 2.5
Mineral matter – 5.8
Phlobaphinite – 2.7
CV Kcal/kg – 5370 – 7180 / 54.02 / Low ash coal with high calorific value (CV)

High Sulphur content of the coal makes its usage restricted to few industries.
There are two coal bearing horizons lower and upper. The lower horizon consist of three coal seams of 0.10 mtrs to 19.0 mtrs thickness. The upper horizon consist of eight seams and the thickness varies from 0.20 mtrs to 4.90 mtrs.
Mining lease is under North Eastern Coal Field

Location:

The Dilli – Jeypore coal field is located in Dibrugarh (Jeypore) and Sivasagar (Dilli) districts of Assam and lies between co-ordinates: N 270 0”– N 270 20’ : E 950 15’ – E 950 30’ E

Accessibility:

(a) Road:

The coal field is well connected by road and can be accessed by Sivsagar – Simalugiri- Namrup – Jeypore road and Dibrugrh – Tengaghat- Nahorkotia – Jeypore road. Sivasagar and Dibrugarh are located at a distance of 40 km and 90 km respectively from Jeypore.

(b) Rail:

The coal field is well connected by Guwahati- Tinsukia broad gauge railway line and it runs parallel to Nahorkatiya- Sivasagar road. The nearest railway station is Namrup, which is located at a distance of 10 km from Jeypore.

The nearest airport is Mohanbari (Dibrugarh), which is located at a distance of 80 km from Jeypore.

Geology

The Dilli – Jeypore coal is of Upper Eocene to Oligocene age, which consists of clay, mudstone, shale, coal and sandstone. As per the exploration carried out by various agencies, two coal bearing horizons have been established in this coalfield. The lower coal horizon contains three coal seams and the upper horizon contains eight coal seams. The thickness of seams varies widely from 0.80 m to 31 m. The seams A1, L2 and basal seam attain the maximum thickness of 19.00 m, 10.30m and 31 m. respectively. The coalfield is a part of an anticline and the dip of the limbs varies from 400 to 550 with local dip of up to 750.

Reserves

Coal reserve in this sector is shown below:

Reserves ( Million ton)
Proved / Indicated / Inferred / Total
9.03 / 14.19 / 30.80 / 54.02

Mineability

Presently only two mines i.eKhotaArda (opencast) and Garampani (Underground) are under operation by AMDC as shown below:

Mine / Type of Mining / Recovery ratio
(Coal : OB) / Production during year 2010-11 (tonnes)
Koilajan / Open cast / 1: 5 / NA
Shelvetta / - / - / NA
KhotaArda
(DimaHasao) / Opencast / 1 :5 / 9202
Garampani (DimaHasao) / Underground / - / 29439

2.Coal Deposit at KarbiAnglongDimaHasao District

Coal
Deposit (s) / Description of deposit
Quality / Reserve (million ton) / Specific features
KarbiAnglongDimaHasao District / Ash % - 5.20 – 25.50
Moisture % - 6.90 – 12.70
Volatile Matter % 33.6 – 47.0
Total Sulphur – 0.4 – 5.59
As an average the form of Sulphur content in Makum coal field is as below:
Organic Sulphur – 45.7-96.4%
Pyritic sulphur – 0 – 35.2 %
SulphateSulphur – 2.3 – 14.6 %
CV Kcal/kg – 5730 – 7706
The Petrographical analysis of Makum coal in % by volume is given below:
Vitrinite – 88.8
Exinite – 3.8
Inertinite – 7.4
Mineral matter – 18.1
CV Kcal/kg – 4285 - 6110 / 1.19 /

Low ash content with high calorific value.
High Sulphur content of the coal makes its use restricted to few industries.
The thickness of coal seam varies from 0.20 mtrs to 5.0 mtrs
The low reserves and poor mineability of these deposit(s) limits their potential for establishment of coal based industry.
The coal mines of Karbianglong district are under lease hold of North Eastern Coal Field while the coal mines of DimaHasao district are under hold of AMDC.

Location:

The occurrence of coal is reported from several localities in Karbi-Anlong and DimaHasao districts of Assam. The prominent coal bearing areas which may be of some economic importance are given below:

Deposit / Location
Koilajan / KarbiAnglong District
Shelvetta / KarbiAnglong District
KhotaArda / DimaHasao District
GaramPani / DimaHasao District

Apart from the above, small occurrences of coal are also reported in Khunbaman river course near village WohpangTogpi, Daigrung river bed near Bagijan , Longlai area of KarbiAnglong district and Dehangi, Dithor on Lanka – Garampani road of Dim Hasao district. The thickness of coal seam in these areas is less than 1 m with limited lateral extension. At this stage of study, these deposits cannot be considered for commercial exploitation.

Accessibility:

Road / Koilajan / The deposit lies on Dimapur-Dillai-Bokajan road. The deposit is 28km from Dimapur and 38km from Diphu by road.
Shelvetta / The Shelvetta deposit lies on Dimapur- Naogoan National Highway No:36. The area is 44km from Dimapur and 40km from Diphu by road.
KhotaArda / The KhotaArda coal deposit is located at a distance of 25 km from Lanka (Nagaon district) on Lanka – Garampani road.
Garampani / The deposit is located at a distance of 88 km from Lanka via Lanka – Garampani (3km post) road.
Raill / Koilajan / The nearest railway station is Dimapur on Guwahati – Tinsukia broad gauge railway line.
Shelvetta / The nearest railway station is Diphu on Guwahati – Tinsukia broad gauge railway line.
KhotaArda / The nearest railway station is Lanka on Guwahati – Tinsukia broad gauge railway line.
Garampani / The nearest railway station is Lanka on Guwahati – Tinsukia broad gauge railway line.

Geology

The coal of DimaHasao belongs to Jaintia Group of Eocene age. The coal seams occur in association with clay, shale, sandstone and fossiliferous limestone. The coal seams are very thin , lensoid and inconsistent in thickness.

Deposit

/ Thickness of coal seam (m)
Koilajan ( with dirt bands) / 0.30 – 1.05
Shelvetta ( with dirt bands) / Seam – I – 0.30 to 5.0, Seam – II – 0.20 to 3.50
Khota - Arda / 0.30 – 3.50
Garampani / 0.35 – 1.50
The dip of the sediments varies from 20 to 150.

Reserves

Reserves ( Million ton)
Deposit / Proved / Indicated / Inferred / Total
Koilajan * / 0.87 / 0.87
Shellvetta / - / 0.523 / 0.523
KhotaArda / - / - / 0.174 / 0.174
Garampani / Not considered since the area shall submerge in KopiliHydel project.
TOTAL / - / - / 1.19 / 1.19

* 1 sq. km mineralized area with average 0.67 m thickness of coal seam

3.Coal Deposit in Tinsukia district

Coal
Deposit (s) / Description of deposit
Quality / Reserve (million ton) / Specific features
Makum Coal field
(Tinsukia District) / Ash % - 3.8 – 19.0
Moisture % - 2.2 – 3.5
Volatile Matter % 18.0 – 45.20
Total Sulphur – 1.9 – 5.73
As an average the form of Sulphur content in Makum coal field is as below:
Organic Sulphur - > 60%
Pyritic sulphur - < 20 %
SulphateSulphur - < 20%
CV Kcal/kg – 5730 – 7706
The Petrographical analysis of Makum coal in % by volume is given below:
Vitrinite – 91.4 – 93.3
Exinite – 4.6 – 5.1
Inertinite – 1.6 – 4
Mineral matter – 1.6 – 3.0 / 260.69 /

Coal of this area has a low ash content with high calorific value.
The thickness of coal seam is

Seam – I – 60 feet.
Seam –II – 7 feet
Seam – III- 20 feet

The coal mines of Makum coal fields are under lease hold of North Eastern Coal Field.

Location

Makum coal field, the largest coal field of North Eastern region is located in Tinsukia district of Assam and lies between co-ordinates: Latitude : 270 15’ N – 270 25’ N and Longitude : 950 40’ E – 960 05’ E.

Accessibility

Road / The important township Margherita that lies on the western end of the coal field is well connected by road network and lies on NH- 38. There are various approach roads, which serves access to the various collieries of Coal India Ltd. The Margherita coal field is located at a distance of 54 km from Tinsukia which is the head quarters of Tinsukia district.
Rail / Makum coal field is well connected by broad gauge railway line up to the eastern part of coal field i.e. Lekhapani, which is connected to Tinsukia, the main rail head of North Eastern Frontier Railway. Tinsukia lies on Tinsukia – Guwahati broad gauge railway line. The rail distance from Guwahati to Tinsukia is 550 km.
Air / The nearest airport is Mohanbari (Dibrugarh), which is located at a distance of 93 km from Margherita.

Exploration Status

Makum coal field has been explored in detail by GSI, DGM Assam and CMPDI in the form of surface sampling, diamond core drilling and sample analysis.

Geology

Makum coal is of Upper Eocene to Oligocene age, which consists of clay, mudstone, shale, coal and sandstone. In all, there are five prominent coal seams as identified by CMPDI and the details of the same are given below:

Seam No. / Seams / Thickness (m)
V / 8 Ft. / 2.42
IV / 5 Ft / 1.66
III / 20 Ft / 6.16
II / 7 Ft / 2.27
I / 60 Ft / 12-45

The strata of Makum coal field are folded and the dip of the limbs varies from horizontal to vertical. In general the dip of strata varies from 450 to 550

Reserves

The estimated reserves of Makum coal field are given below:

Reserves ( Million ton)
Proved / Indicated / Inferred / Total
249.65 / 9.85 / 1.19 / 260.69

Mineability

The strata associated with coal seams are of argillaceous nature represented by mudstone, clay, siltstone and sandstone. The occurrence of clay creates problems in opencast mining as the clay beds become soft when soaked in rainwater. The steep dips of strata also create problem of slope stability. Presently, coal is being exploited from two opencast and three underground mines, the details of the same are given below:

Mine / Type of Mining / Recovery ratio
(Coal : OB) / Production during year
2010-11 (tonnes)
Tikak / Opencast / 1: 8 / 455073
Tirap / Opencast / 1: 8 / 530008
Bargolai / Underground / - / 0
Tipong / Underground / - / 1522
Ledo OCP / Underground / - / 113896

The whole of the coal bearing area of Makum coal field is under mining lease of North Eastern Coal fields, a subsidiary of Coal India ltd.

Utilization of Coal in Assam:

Following are the users of coal in Assam:

Present Users
Categories / % use of Total production of Coal
Paper Industry / 19%
Brick industry / 40%
Cement Industry / 4%
Tea / 3%
Other including Coke industry / 34%

[Source : NEDFi]

2.Limestone:

Limestone occurs primarily in the districts of DimaHasao and Karbi-Anglong. The Limestone of DimaHasao is well exposed in the area along Garampani-Lanka road. Large exposures are found in Umrangshu area.

The limestone reserves have been estimated as follows:

Proved reserves – 166 Million Ton
Indicated reserves – 488 Million Ton
Inferred reserves – 49 Million Ton

Total - 703Million

Limestone Deposit of Assam is give below:

Limestone Deposit in Assam

1.Limestone Deposit at DimaHasao district:

Limestone deposit(s) / Deposit description
Quality / Reserves (MT) / Specific features
Garampani- New Umrangshu (DimaHasao district) / SiO2 (%) : 3.15 – 7.84
Al2O3 (%) : 1.92 – 3.96
Fe2O3 (%) : 1.35 – 4.48
CaO (%) : 39.75 – 50.14
MgO (%) : 1.31 – 2.15
LOI (%) : 25.85 – 38.70 / 1354.20 /

Large reserves of limestone exist.

The limestone reserves are high grade to cement grade and have the potential to sustain a large size cement plant.
The limestone is high in R2O3 content, which requires detailed study to establish its use as high grade limestone for lime and chemical industries.
The infrastructure facilities are poor.
Part of the area leased out to various cement plants in the area.

Location:

This limestone deposit is a NE continuation of Nonghlie – Sutnga limestone belt of Meghalaya and can be traced along 46 km length from Garampani –Umarangshu to Panipur along Garampani Lanka road. The co-ordinates of the deposit(s) are given below:

Location / Co-ordinates
Garampani / N 25030’ 00” – 25030’ 52” : E 92039’ 00” - 92039’ 45”
New Umarangshu - Juripahar / N 25030’ 00” - 25035’ 00” : E 92045’ 00” – 92050’ 00”
Panipur / N 25044’ 00” : E 92049”00”

Accessibility

Road / Garampani / The limestone deposit is located at a distance of 120 km from Haflong, the district head quarters of DimaHasao. Guwahati is located at a distance of 232 km via Shillong and 272 km via Nagaon. Shillong is located at a distance of 122 km via Jowai.
New Umarangshu - Juripahar / The limestone deposit is located at a distance of 138 km from Haflong, the district head quarter of DimaHasao. Guwahati is located at a distance of 250 km via Shillong and 254 km via Nagaon. Shillong is located at a distance of 140 km via Jowai.
Panipur / Panipur is located at a distance of 28 km from Garampani on Garampani – Lanka – Nagaon road.
Rail / The nearest railway station is Lanka on Guwahati – Tinsukia broad gauge railway line that is located at a distance of 75 km from Garampani.
Air / The nearest airports are at Shillong and Silchar , which are located at a distance of 250 km and 220 km respectively from Umarangshu.

Geology:

The New Umarangshu limestone deposit belongs to Sylhet limestone formation of the Jaintia Group of Eocene age. The deposit extends over a strike length of 46 km (from Garampani to Panipur) with a width of 2.4 km and the thickness of limestone ranges from 30 m to 80 m. It is overlain by shale and sandstone.

Reserves :

Block Area (sq km ) / Reserves (Million ton)
Proved / Indicated / Inferred / Total
New Umarangshu – (2.02) / - / - / 70 / 70
AIDC (3.75) / 101 / - / - / 101
AMDC (1.80) / 59 / - / 76 / 135
High Grade Block(1.33) / - / - / 86 / 86
Juripahar (8.50) / 184 / 325 / 450 / 959

Panipur

/ - / - / 3.2 / 3.2
TOTAL / 1354.20

Utilization :

Present Users:

Presently the limestone from the area is being used for cement manufacture. The high grade limestone from AMDC mine is being used as sweetener by Vinay Cement Ltd.

Potential Utilization:

The quality of limestone is highly variable from low grade to high grade. The limestone from the area can be used for :

-Manufacture of grey cement.

-Production of lime for use in paper and other chemical industries subject to further detailed studies.

2.Limestone deposit at Karbi-Anglong district:

Limestone Deposit(s) / Deposit Description
Quality / Reserves (Million ton) / Specific Features
Shelvetta – Koilajan – Dillaiparbat
(Karbi-anglong district) / SiO2 (%) : 37.88 – 48.72
Al2O3 (%) : 4.21 – 10.22
Fe2O3 (%) : 0.22 - 3.00
CaO (%) : 37.88- 48.72
MgO (%) : 0.22-3.00
LOI (%) : 30.62-39.30 / 73.87 /

The limestone is low grade to cement grade and shows wide variation in quality.

The deposit is covered by thick soil cover.

The deposit at Dillaiparbat is steeply dipping which makes mining difficult.
Part of the area leased out to Cement Corporation of India & KarbiAnglong Chemicals (Pvt) Ltd.

Location:

The occurrence of limestone is reported at several localities in KarbiAnlong district of Assam. The location details of these limestone deposit(s) are given below:

Deposit / Location
Koilajan / N 26000’ : E 93045’
Shelvetta / N 25054’ – 26006 ’ : E 93015’ – 93041’
Dillaiparbat / N 26000’ : E 93025’

Accessibility:

Road / Koilajan Deposit / The deposit lies north west of Dimapur and north east of Diphu on Dimapur - Dillai – Bokajan road. The deposit is located at a distance of 28 km from Dimapur and 38 km from Diphu. Diphu is the district head quarter of KarbiAnglong district. Nagaon is located at distance of 144 km from the deposit.
Shelvetta / The Shelvetta deposit lies on Nagoan - Dimapur National Highway No. 36 at a distance of 122 km from Nagaon. The district head quarter Diphu is located at a distance of 40 km due southeast of Shelvetta.
Dillaiparbat / The deposit lies on Dimapur-Dillai – Bokajan road. And is 28km by road from Dimapur and 38km by road from Diphu.
Rail / The nearest railway station is Dimapur on Guwahati – Tinsukia broad gauge railway line.
Air / The nearest airport is Dimapur, which is located at a distance of 40 km from Shelvetta and 28 km from Koilajan.

Geology:

The limestone deposit of the area belongs to Sylhet limestone formation of the Jaintia Group of Eocene age. It is underlain by coal bearing Basal sandstone and overlain by sandstone, shale and clay of Kopili formation. The limestone outcrops at Dillaiparbat area only while the rest of the area is concealed under a thick soil cover.

Quality:

The quality of limestone as analyzed by exploration agencies is given below:

SiO2 (%) / Al2O3 (%) / Fe2O3 (%) / CaO (%) / MgO (%) / LOI (%)
37.88 – 48.72 / 4.21 – 10.22 / 0.22 - 3.00 / 37.88- 48.72 / 0.22-3.00 / 30.62-39.30

The limestone is highly variable in quality with comparatively high Al2O3 content.

Reserves:

Deposit / Reserves ( Million ton)
Proved / Indicated / Inferred / Total
Koilajan / - / - / 31 / 31
Shelvetta / - / - / 10 / 10
Dillaiparbat / 18.18 / 14.69 / - / 32.87
TOTAL / 18.18 / 14.69 / 41 / 73.87

[Source: NEDFi]

Industries based on Limestone:

Assam has 20 nos of hydrated/dehydrated lime factories to feed the requirement of local market. The major market for these units are HPC JagiroadPanchgarm , IOC, PHE department, etc. Apart from that based on Limestone of Assam & Meghalaya, 33 nos of Cement plants are now operating in Assam with an installed capacity of 3223053 MT per annum. The major players in the state area Dalmia, Star Cement, TOPCEM, Purbanchal Cement, etc.

3.China Clay:

The estimated China Clay reserves are 0.24 million tones with deposits in the Karbi-Anglong district at:

Deopani:1 million tone

Sheelvata:58000 tonnes

Chilonijan:175094 tonnes

4.Feldspar:

The feldspar of deposit of 13000 tonnes are found in the following areas:

RangsaliGoalpara

HahimKamrup

KoilajanKarbi-Anglong

5.Granite:

Reserves of Granite in Assam are about 10 billion cubic metre. The occurrence of this mineral is found in the districts like Dhubri, Bongaigaon, Kokrajhar, Kamrup, Nagaon, Morigaon and Karbi-Anglong.

6.Sillimanite

Sillimanite deposit is found in places like Chippinala, Chipriangso of Karbi-Anglong district. Approximate deposit may be about 50 million tones. Chemical properties of these materials are as follows:

Contain Al2O3 in grade-1 is about 58.4%, in Grade-2 is about 35.5% and in Grade-3 is about 13.05% respectively.

7.Quartzite:

Quartizite is found in places like Jiajuri, Thansjuri Hills, Borhola and Chapanala in Nagaon district. Approximate deposit may be about 17 million tones.

8.White Clay (Fuller’s earth):

White clay is found in places like Subankhata & Bhutan Khuti of Baksa district. Approximate deposit may be 20 million tone.

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