2. Introduction
Steel scenario
Physical and chemical properties
Occurrences
Classification and uses
World chromite production
Global reserves and demand
List of companies engaged
Potential of India
Mining methods
Beneficiation
Cost variation
3. To gain the basic knowledge of chromite
Its formation
Global presence
Uses
Mining methods
Beneficiation practice
4. Introduction
Chromite occurs as a chromium spinel, a complex
mineral containing magnesium, iron, aluminum
and chromium in varying proportions depending
upon the deposit. Chromium is replaced by ferric
iron & aluminum to form hercynite(FeAl2O4)and
iron is replaced by magnesium to form magnesio
chromite(MgCr2O4).
It is this replacement that improves the Cr/Fe ratio
in chromite. Chromium ore occurs exclusively in
ultramafic igneous rocks.
5. 4 tons Stainless steel
1 Ton Ferro chrome
2.5 Tons of chromite ore
6. Properties of Chromite
Chemical Classification oxide
Color
dark gray to black, rarely brownish
black
Streak dark brown
Luster metallic to submetallic
Diaphaneity opaque
Cleavage none
Mohs Hardness 5.5 to 6
Specific Gravity 4.0 to 5.1 (variable)
Diagnostic Properties luster, streak
Chemical Composition
FeCr2O4 with magnesium
substituting for iron in significant
amounts
Crystal System isometric
Uses an ore of chromium
13. Country
Production
2011 ('000
metric tons)
Production
2012 ('000
metric tons)
Reserves('000
metric tons)
South Africa 10,200 11,000 200,000
Kazakhstan 3,800 3,800 210,000
India 3,850 3,800 54,000
Others 5,450 5,300 N/A
World Total 23,300 24,000 >460,000
15. • African Consolidated Resources Plc
• Anglo Pacific Group plc
• ASA Metals (Pty) Ltd
• Chrometco Limited
• Chromex Mining
• Consolidated Minerals Limited
• Eurasian Natural Resources Corporation
• International Ferro Metals South Africa (Pty) Limited
• Kefid Machinery
• Kemai Machinery & Equipment Co Ltd
• Kermas Group Limited
• Mas Minerals
• Merafe Resources Ltd
• Metal Bulletin Events
• Southbridge International Trade Corporation
• vpr Mining Infrastructure Suarl
• Zimbabwe Alloys Chrome Limited
• Zimbabwe Mining & Smelting Co. (Pvt) Ltd
List of Company
16. CHROMITE ORE POTENTIAL OF INDIA
India
1st IN
EXPORT
OF
CHROME
ORE
5th IN
TERMS OF
CHROME
ORE
RESERVE
3rd in
chromite
production
17.
18. CHROMITE ORE POTENTIAL IN INDIA
POSSIBLE RESERVE
(69%) (31%)
TOTAL RESOURCE ─ 213 Mt
EASTERN INDIAN STATE
OF ORISSA
(OVER 95% OF TOTAL)
SUKINDA
ULTRAMAFIC
BELT
BAULA-NAUSAHI
IGNEOUS
COMPLEX
19. CHROMITE ORE POTENTIAL IN INDIA
“CHEMISTRY” OF CLEAN CHROME SPINELS FROM ORISSA
Location Cr/Fe Cr2O3% MgO% FeO% Al2O3%
Sukinda 3.35 57.5 14.01 15.12 12.60
3.30 58.7 12.57 15.57 11.82
3.86 58.9 16.10 13.40 10.70
3.30 56.6 11.70 15.60 11.10
Boula-
Nausahi
2.04 54.9 11.64 23.70 9.82
1.80 52.8 10.50 25.65 9.80
1.67 49.4 8.89 26.08 14.40
INDIA COMES UNDER HIGH-GRADE GROUP WITH COUNTRIES
HAVING AVERAGE Cr2O3 GRADE OF 39%.
20. Rock containing chromite ore
Mining Method
Extraction of the Chromite Ore
Both surface and underground mining methods will be used to mine the
chromite. Mining produces both ore and waste rock. Waste rock consists of
all other non-chromite bearing rock excavated during mining.
Surface Mining
Chromite ore is mined by surface methods. This includes an open pit from which surf ace
material, non-chromite bearing overburden and chromite ore,
will be excavated. The chromite ore containing rock will be drilled, blasted, removed and loaded
onto large trucks for hauling to the crusher and ore processing facility
Underground Mining
The transition to underground mining will be
considered once it is necessary to extract rock from
greater depths. The underground mine will be
reached from the bottom of the open pit. Blast hole
stopping methods will be used for underground
mining. Stopping occurs in underground mineral mining
when the surrounding rock is strong enough to allow
the drilling, blasting, and removal of ore without caving
21.
22. CHROMITE BENEFICIATION IN INDIA
PAST
SCENARIO
MINING OF
HIGH GRADE
ORE
LEAVING LOW AND
MEDIUM GRADE ORES
STACKED AS WASTE
USE OF MANUAL
METHODS FOR
DRESSING
23. Generally Chrome ore deposits are classified as
Siliceous type (silica rich)
Ferruginous type (iron rich)
Associated gangue minerals are
Talc
Quartz
Hematite
Goethite
Limonite
Serpentine
Pyroxinite
24.
25.
26. Comminution(to prepare the ore for subsequent unit operations)
and concentration. The feed unit incorporates screening of the
ROM ore to 75mm from -220mm followed by two stage
crushing(primary& secondary crusher) and screening to produce
less than 3mm size fraction. This fraction is further ground to less
than 1mm and then upgraded utilizing conventional gravity
techniques like spiral concentrator and shaking table in the
concentration section.
Low grade chrome ore with Cr2O3 of about 20-30% of sukinda
region of India ,can be beneficiated to a marketable grade of 45%
Cr2O3 with 45-50% recovery, by grinding the chrome ore(d80
passing size 260 microns).
Circuit descriptionCircuit description
