Market Survey on Copper - Indian Bureau of Mines

lithologic zones. The major copper ore occurring in the Dhukonda deposit is
chalcopyrite and it is confined in the coarse grained quartzitic rocks. The
average copper content in the Dhukonda area is assessed as 1.51 per cent.
v) Chitradurga Copper Belt
This deposit extends from Gadag in the north to Srirangpatnam in South
over a length of 460 km with a maximum width of 40 km near Chitradurga in
the state of Karnataka. The general trend is NNW-SSE. The host rock
comprises meta-sediments and meta-volcanics which are traversed by dykes of
chlorite and gabbro. The sulphide mineralisation with copper, lead, zinc,
antimony, arsenic and silver values is located over a strike length of 40 km in
the eastern part of the deposit. This mineralised belt is designated as
Chitradurga Sulphide belt. Copper mineralisation is prominent in Bellugudda,
Ingaldhal, Kuchiganahalu sector, over a strike length of 5 km. The copper ore
occurs mainly as chalcopyrite, malachite, pyrite and arsenopyrite
disseminations. The copper contents vary from 0.77 to 1.72%.
vi) Ambamata Multimetal Deposit
This deposit is located in the Banaskantha district of Gujarat in the
temple town of Ambamata. The rock types found in the area are quartz schist,
biotite and sericite schist, which belong to Delhi super group. These rocks are
intruded by meta-basics and Erinpura granite. The surface indications are in the
form of acurite and malachite. The primary sulphides occurs in the region are,
sphalerite, galena, chalcopyrite and pyrite. The copper mineralisation occurs in
arenaceous rock. The total strike length of Ambamata deposit is 2.14 km
trending NW-SE and the maximum width is 700 metres.
vii) Rangpo Multimetal Deposit, Sikkim
This deposit is situated at Rangpo in Sikkim about 40 km south of
Gangtok. The mineralised zone extends from Bhotang, Rangpo in East Sikkim
district to Dikchu in North Sikkim district. The rock formations in the area are
represented by the rocks of Daling group consisting of chlorite-sericite,
phyllites, quartzites and metabasic rocks. The metabasics and chlorite schists
which host the ore are highly folded and faulted. The sulphide mineralisation
which occurs in the form of bands consists of chalcopyrite, pyrrhotite, sphalerite
and galena.
3.2 BENEFICIATION
The copper content in sulphide ores is generally too low (0.3 to 2%) to permit
direct smelting. The copper minerals are generally associated with worthless gangue
constituents which, if not removed, will require large capacity smelting furnaces as
well as enormous quantity of electrical and thermal energy. Besides, copper ores also
contain some base metal minerals which need to be removed for ensuring smooth
smelting and refining operations. Therefore, it is necessary to beneficiate copper ores
to produce smelter grade concentrate. A diagramatic representation of principal
production process is given at Plate 3.IV.
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