Here is your essay on Copper

It is the most important non-ferrous metal and was the earliest metal used by man.

Ore-minerals:

In nature copper occurs in four principal formes, viz , sulphides, carbonates, oxides and as native copper. Of these the bulk of copper is obtained from the sulphide ores. The chief economic ore-minerals however, are

To be economically exploited a copper ore should contain at least 2.5% of copper. In modern times ores with 1 % of copper are also used.

Origin:

All large copper ore bodies are closely connected with igneous rocks mostly of an acidic nature. It is mostly believed that copper deposits are formed through hydrothermal solutions, either as cavity-filling or replacement deposits. But replacement has been a more dominant process than cavity filling.

Only a few deposits have been formed by magmatic concen­tration or by contact-metasomatism.

The process of oxidation and supergene enrichment also plays dominant role in giving rise to workable deposits of secondary copper sulphide ores:

Mode of occurrence:

Copper deposits may occur as

(a) Disseminated ore bodies:

Where the copper minerals; re generally dispersed in a large volume of rock. They are generally of low grade. The porphyry-copper deposits of USA are of this type.

(b) Massive, irregular or lenticular ore bodies, which are formed by the process of replacement.

(c) Vein deposits or lodes:

In which the copper bearing solutions percolating along shear zones and rock-fractures deposit copper minerals with changes of temperature and pressure forming fissure-veins, e g.,Copper deposits of Singhbhum.

(d) Deposits following stratigraphic beds, as are the case with the deposits of Khetri (Rajasthan).

Distribution:

(i) In Andhra Pradesh, the most important copper deposits are the Agnigundla-deposits.

(ii) In Bihar, in the Singhbhum district, a copper bearing belt of about 80 miles long occurs. Here the copper ores occur as veins in the country rock consisting of mica-schists, quartz-schists, chlorite-schists, biotite-schists, granite and granite-gneisses. The veins are best developed along a zone of over thrust, where they form well defined lodes, as seen at Rakha mines, Mosabani and Dhobani. Individual lodes normally consist of one or more veins one inch to two feet thick, the average being 5 to 7 inches.

(iii) In Madhya Pradesh, the important deposit is the Malan Jhakhand copper deposit, where copper ores occurs in the form of vans within dolomitic limestone.

(iv) The Khetri copper deposit of Rajasthan is one of the important copper deposit in the country. This belt has 3-richly mineralised sections-Madhian, Kolihan and Akhwali. The copper ore bodies occut in phyllites, slates and schists of the Ajabgarh series (Delhi system) as irregular stringers, fillings of schistose planes and fractures and disseminations in the host rock. The minerali­sation in Rajasthan copper belt is epigenetic and seems to have occurred under mesothermal conditions from post-Delhi (Erinpura) granite magma.

(v) Other important copper deposits of the country are follows:

(a) Himachal Pradesh. Kangra, Kulu valley.

(b) Mysore. Chittaldrug, Hassan, Bellaiy districts.

(c) West Bengal. Darjeeling, Jalpaiguri districts.

(d) Sikkim. Rangpo and Dickchu deposits which are found to occur in association which the metamorphic rocks belonging to the Daling series.

Economic uses:

The metal is of great industrial importance, because of its high electric conductivity, high ductility and malleabi­lity. Thus it is mostly used in electrical manufactures. Besides, the copper alloys are used in buildings, automobiles, air planes, naval ships, house hold utensils as well as in metallurgy and paints.