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Seminar on iron ore beneficiation in india
1. C U R R E N T P R A C T I C E S I N I N D I A N
IRON ORE
BENEFICIATION
DEPARTMENT OF MINERAL ENGINEERING
G O V E R N M E N T C O L L E G E O F E N G I N E E R I N G K E O N J H A R
Ankit Kumar Panda
By
Regd. No.:
1501104248
7TH SEMESTER
MINERAL
ENGINEERING
2. Contents
1. Introduction
2. Formation
3. Origin And Classification Of Iron Ore Deposits
4. Reserves/Resources
5. Production Demograph
6. Beneficiation !
7. Common Unit Operations For Beneficiation Of Iron Ore
8. Beneficiation Plants In India
9. Future Trends Of Beneficiation In India
10. Indian Scenario
11. Iron Ore Beneficiation Plants In India
12. Bibliography
3. Introduction
Iron is the fourth most abundant mineral on earth having a reserve of 170 billion
tonnes of crude iron ore.
Iron & steel is the driving force behind industrial development in any country.
The mining of iron ore, an essential raw material for Iron & Steel Industry, is
arguably of prime importance among all mining activities undertaken by any
country.
With the total resources of over 33.276 billion tonnes of haematite (Fe2O3) and
magnetite (Fe3O4), India is amongst the leading producers of iron ore in the
world.
4. Formation
Indian Iron ore is from pre-Cambrian age. There are two types of formation from
the pre-Cambrian iron ore.
o Algoma type : Dominant in Archean age and characterized by thin
banding and absence of oolitic and granular texture closely associated with
volcanic and greywacke sediments.
o Superior type : Characteristic formation of Proterozoic age closely
associated with clastic sediments like quartzite, dolomite and pelitic rocks
without showing an direct relation with volcanic association.
5. Origin and classification of Iron ore deposits
The iron ore deposits of India can be broadly divided in to the following six groups on
the basis of mode of occurrence and origin:
o Banded Iron Formation of Pre-Cambrian Age
o Sedimentary iron ore deposits of siderite and limonitic composition
o Laterite ores derived from the sub-aerial alterations
o Ores formed by magmatic activity
o Titaniferous and vanadiferous magnetites
o Fault and fissure filling deposits
6. RESERVES/RESOURCES
Haematite and magnetite are the most important iron ores in India.
As per NMI database based on UNFC system, the total reserves/resources of haematite as
on 1.4.2015 has been estimated at 22,487 million tonnes of which 5,422 million tonnes (24%)
are under 'Reserves' category and the balance 17,065 million tonnes (76%) are under
'Remaining Resources’ category.
98% magnetite reserves/resources are located in five States, namely, Karnataka (7,802
million tonnes or 72% reserves) followed by Andhra Pradesh (1,392 million tonnes or 13%),
Rajasthan (617 million tonnes or 6%), Tamil Nadu (507 million tonnes or 5%) and Goa (226
million tonnes or 2%). Assam, Bihar, Chhattisgarh, Jharkhand, Kerala, Maharashtra,
Meghalaya, Nagaland, Odisha and Telangana together account for the remaining 2%
resources.
7. “Cut off grade” means the minimum economic assay grade of the mineral
for a deposit below which the mining operations become unviable in the
present market dynamics or end use quality. It may vary from deposit to
deposit depending upon the market conditions.
The revised (25th April, 2018) Threshold value of iron ore minerals by IBM are:
I. Hematitic Ore - 45% Fe(Min.)
II. Hematitic Siliceous Ore - 35% Fe(Min.)
III. Magnetite Ore-15% Fe (Min.)
Continued…
8. State-wise Production in India
Odisha Chhattishgarh Karnataka
Jharkhand Goa MadhyaPradesh
Other
(*According to Mineral Year Book 2017 – Indian Bureau of Mines)
Production Demograph
9. BENEFICIATION !
In general, the practice adopted by major steel plants in India is to consume medium
to high-grade ores (+62% Fe). It is achieved by resorting to selective mining keeping
the cut-off up to as high as 58-60% Fe. Therefore, prime objective of beneficiation is to
meet the physical standards as required for iron making.
The entire run of mine (r.o.m.) iron ore is processed, Comprise:
1. Dry-Processing
high-grade(> 65% Fe) hematite iron ore are subjected to dry process of beneficiation
to obtain calibrated lumps i.e., -40+ 10 mm (for blast furnace); -18+6 mm (for sponge
iron) and fines (-10/6 mm) products.
10. Continued…
2. Dry-cum-wet Processing
Beneficiation of fine fraction (-10mm), is processed in mechanical
classifiers, hydrocyclones, etc. to obtain 10+0.15 mm size products that
constitutes the feed for sintering.
3. Wet Processing
The wet processing circuit is generally practiced for low/medium-grade (60-62%
Fe) hematite iron ore. The process consists of multi-stage crushing followed by
different stages of washing in the form of scrubbing and/or wet screening,
classification etc.
12. COMMON UNIT OPERATIONS FOR BENEFICIATION OF IRON ORE
Types of Process Uses For
Heavy media separation
Flotex
Cyclone
Magnetic Concentrator
• Low Intensity Separator
• Medium Intensity Separator
Spiral
Tables
• High Intensity Separator
Forth Flotation
Gravity concentration
Multi gravity separator
Washing and wet scrubbing
-50+3 mm particle size
<1mm size of particles
Both classification and dewatering
(based on magnetic susceptibility)
1000 to 2000 guss
2000 to 7000 guss
1 mm to 0.03 mm
Cleaning & scavenging of -1+0.03mm particles
7000 to 20000 guss
Finer than 65 mesh(#)
Heavy & valuable iron ore, based on Sp. gravity
Ultra fine particles
Lumpy iron ore
13. Beneficiation Method Percentage of Iron Ore
Treated
• Magnetic Separation 41.6
• Flotation following
Magnetic Separation 51.2
• Subtotal 92.8
• Flotation 6.3
• Gravity Concentration < 11
• Total 100
Percentage of iron ore treated with most common methods, in weight
percentage, are:
Continued…
14. Process Flow Sheet of Noamundi, Singhbum
Jharkhand, TISCO
Process Flow Sheet of ESSAR Concentrator,
Kirandul, Bastar
Process Flow Sheet of Bailadila (Deposit-14)
NMDC
Beneficiation Plants in India
15. Process Flow Sheet of Bolani, SAIL, Orissa Process Flow Sheet of Donimalai, Bellary, NMDC Process Flow Sheet of Fomento, Goa
Continued…
16. A close look at the beneficiation/processing practiced in the country reveals that:
1. Most of the iron ore mines in India have been operated by selective mining for maintaining high-grade of ore.
2. To maintain high-grade ore, low-grade lumps and laterite are rejected. Generally, classifier fines
(-10+0.15 mm) are not processed any further and as such used for sinter making.
3. The current industrial practice of iron ore washing is oriented towards product with 2.5-3.0 A12Q3 in lumps
and around 5%A12Q3 in sinter fines.
4. The present iron ore washing circuit produces slimes, particles below 0.15 mm (-100mesh) which are discarded
as waste. The generation of slimes is about 20-25% of the feed to the plant.
5. The present industrial practice causes huge loss of iron values in process/mine rejects and their stacking has
adverse effects on environment causing ecological imbalance.
6. No low-grade ores are exploited.
Continued…
17. Future trends of Beneficiation in India
Extensive Research and Development (R&D) work has been undertaken during last
decade by Ore Dressing Laboratory of IBM engaged in beneficiation of iron ore,
namely r.o.m. ore (high, medium, low & sub-grade), stacked fines from old dumps
(-10 mm), slimes (-100 mesh) from tailing ponds and various process stream
products of existing processing plant, to evolve a suitable process flow sheet for
recovery of valuables from various types/characteristics of iron ore in India
Some developments are:
Beneficiation of
High-grade Iron Ore Associated with little Shale & Quartz Gangue Impurity.
Medium-grade Iron Ore Associated with Shale & Quartz Gangue Impurity.
Low /Medium-grade Iron Ore Associated with Goethite (over 20%) Impurity
Low /Sub-grade ore Associated with Goethite/Limonite (over 40%) Impurity
18. Iron ore beneficiation facilities in the country are highly inadequate i.e.,
only 52 concentrators cater to the need for iron ore production of about 220
MTPA (mines-316). Of this around 50% of the concentrators are exclusively
in Goa region (production 33 MTPA; mines 72) dedicated solely for export
and not meant for domestic consumption.
INDIAN SCENARIO
Iron Ore Beneficiation Plants in India
19. In most of these concentrators, beneficiation process technology is limited to sizing,
washing and classification to meet the size requirement with nominal rejection of silica
and alumina impurities. Such washing facility was basically successful on account of
selective mining of medium to high-grade iron ore at a cut-off grade of 60% Fe.
However, such practice of processing may not be of any help once low-grade ores are
mined at the threshold value i.e., 45% Fe to augment production.
Major beneficiation plants in the country are owned by M/s SAIL, NMDC, TISCO,
OMC, JSW Steel Ltd, M/s V.M.Salgaoncar Pvt. Ltd, Sesa Goa Ltd, Socedade de
Fomento, Goa etc
Continued…
20.
21. Bibliography
Indian Bureau of Mines: www.ibm.nic.in
https://en.wikipedia.org/wiki/Iron_ore
Iron & Steel – vision 2020 by Indian Bureau of Mines
THE GAZETTE OF INDIA : EXTRAORDINARY (No. C-284/3/CMG/2017)