Manufacture process of copper

Md. Habib Ullah Khan, Lecturer, ME, KUET

Engineering Metallurgy

Engineering Metallurgy

Engr. Md. Habib Ullah KhanLecturer, ME, KUET,

Bangladesh

MANUFACTURE OF COPPER(Welsh & Manhe’s Process)


MANUFACTURE OF COPPER:There are various copper ores available e.g. Copper pyrite (CuFeS2), Cuprite (Cu2O), Chalcocite (Cu2S) etc. Copper is mainly extracted from Copper pyrite.

Several processes to extract copper from ores 1. Reverberatory Furnace Process (Welsh Process)2. Blast Furnace Process (Manhe’s process)

These 2 processes are used to extract copper from ores which contain sulphur.


The main steps of extraction of copper from ores are

i. Crushing and Concentrationii. Roastingiii. Smeltingiv. Bessemerisationv. Refining

MANUFACTURE OF COPPER (WELSH+MANHE’S):


i. Crushing and Concentration:

At first, Copper pyrite is crushed in a crusher machine. Then concentrated by froth flotation process.Oil is used in the froth floatation process because the ore contains sulphur.


Fig.: Froth Floatation


ii. Roasting:

The concentrated ore is heated in the reverberatory furnace (Welsh Process)

Roasting removes the moisture and volatile materials e.g. Sulphur, Phosphorus, Arsenic and Antimony as their oxides

Blister copper forms in this process. It contains 2-3% impurities which is purified by melting in a furnace hearth.


Fig.: Welsh Process



iii. Smelting:a) The roasted ore is mixed with coke

and silica (sand) and charged into the top of the blast furnace.

b) Air is forced through pipes and reaction occurs leading to the formation of slag and a matte corresponding with the coarse metal of welsh process.

c) The slag and matte flow into the fore hearth, the slag running away continuously from an opening in the fore hearth.

d) Matte is collected from matte hole

Fig.: Manhe’s Process



iv. Bessemerisation:

a. The matte is poured into a Bessemer converter and a current of air is forced through it.

b. Air is admitted through ports in an annular pipe above the bottom. The same reaction occurs as Welsh process and copper is produced

Sulphur is burnt of as sulphur oxide, iron passes into the slag as silicate and arsenic etc. as oxides and sublime.


v. Refining:

2 ways of refining crude copper:

vi. Remelting it in a furnace vii. Electrolysis of crude copper:

Crude copper is used as anode and a thin sheet of pure copper acts as cathode


Manufacture process of copper

Engineering

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