CHROMITE MINERALISATION INSUKINDA ULTRAMAFIC COMPLEX

RUPALI LOHANIGEOLOGIST

35TH OCGBATCH-F

Chromite Industrie Chromite is the only economic source of chromium.

It belongs to the Ferrous Group of metals along with Iron and Manganese.

The properties of chromium that make it most versatile and indispensable are resistance to corrosion oxidation wear enhancement of hardenability.

For manufacture of various types of stainless steel and alloy steels, besides its other uses in chemical and refractory .

- ONLY ORE OF CHROMIUM METAL.

- BELONGS TO FERRUS GROUP OF METAL ALONG IRON & MANGANESE.

-Sp.GRAVITY 4.5 to 5 AND HARDNESS 5.5 .

- IN STEEL INDUSTRY.- WITH Ni and Fe PRODUCE NICHROME,USED FOR MAKING OVENS ETC.-PLATING ON AUTOPARTS OF APPLIENCES AND OTHER PRODUCT AND GIVEN THE NAME CHROME PLATE.

The Sukinda ultramafic field is confined to an east-west trending valley lying between the Daitari hill range and Mahagiri range.

The ultramafic rocks of Sukinda valley are emplaced within a sedimentary sequence of Iron Ore Supergroup.

The belt extend from Kansa in the east to Maruabil/ Kathpal in the west in an ENE-WSW direction for over 25 km.

SUKINDA ULTRAMAFIC COMPLEX

SUKINDA ULTRA MAFIC COMPLEX

GEOLOGICAL MAP OF SINGHBHUM ARCHAEAN NUCLEUS

Generalised Geological map of Sukinda UMF Complex

The chromite mineralisation is confined to a Precambrian ultramafic body which has intruded in the form of a lopolith into the Precambrian supracrustals

The intrusive has a width of 2 to 5 km and extends for a length of nearly 25 km in an ENE-WSW direction from Kansa in the east to Maruabil and beyond, on the west.

The ultramafic body consists of magnesite-rich serpentinised dunite-peridotite with chromite bands besides subordinate amount of pyroxenite without chromite association.

CHROMITE MINERALISATION

The repetition of dunite members and chromite ore seams has been attributed to rhythmic layering within ultramafic complex.

The dunite-peridotite members are highly serpentinised and intensely lateritised giving rise to a nickeliferous laterite profile of variable thickness.

SUKINDA ULTRA MAFIC (LAYERED CHROMIFEROUS DUNITE)

Chromite layering

Lower Brown Ore seam Upper Brown Ore seam Sukrangi Ore seam Kamarda Ore seam Grey Ore seam or Mahagiri Ore seam

CHROMITEGSEAMS OF SUKINDA ULTRAMAFIC

COMPLEX

MAHAGIRI CHROMITE SEAM

OTHER CHROMITE SEAMS

- Fine grained lumpy ore

- Dipping south into Mahagiri Hills.

- Friable and partly lumpy

- Steep dip towards North.

LOWER BROWN ORE SEAM (SEAM-1) IS 40m THICK (THICKEST SEAM IN THE WORLD ).

OTHER SEAMS ARE 200m TO 2Km STRIKE AND SEAM-1 HAS STRIKE LENGTH 7Km.

FRIABLE CHROMITE ORE

NICKELIFEROUS LATERITE

The ore bands have dips ranging from 25º to 85º but in general it is 75o.

The ore bands have dips ranging from 25º to 85º but in general it is 75o.

The wall rocks are generally composed of soft, limonitised, silicified and talcose or serpentinised ultramafic rocks.

The ore bands locally exhibit swelling and pinching both along the strike and dip.

CHROMITE MINING IN SUKINDA

GRADE The ore is mostly of charge chrome and metallurgical grade with

+48% Cr2O3

1-6% SiO2 5-8% C 0.4% S 0.3% P Only the upper weathered portions to a maximum thickness of 30 m may show 30-35% Cr2O3.

RESERVE Chromite ore resources in India total 232 million tones.

Lumpy ore reserves constitute hardly 10 % of the total reserve base.

World chromite resources are placed at over 12 billion tonnes.

Over 95% resources are located in South Africa, Zimbabwe and Kazakhstan.

As per UNFC, total resources (Provisional) of chromite in the country are 232 MT, comprising 66 MT reserves (28%) and 166 MT remaining resources (72%).

More than 95% resources of chromite are mostly located in Sukinda Complex of Orissa.

The remaining 5% reserves of the country are scattered over Jharkhand, Maharashtra, Tamil Nadu, Andhra Pradesh and Manipur.

A pure mineral may assay FeO 32.1% and Cr2O3 67.9%.

THANKS FOR YOUR KIND ATTENTION……