Basics of converting operation

It is important that the reader should consult any text book on non-ferrous metal extraction to familiarize with the process of converting. Detailed description about the converting process is not given here. The following description is given with a view to solve the problems on converting.

In production of copper, converting is an important unit process. Matte, which is a mixture of copper and iron sulphide, is treated in Pierce-smith-Converter. The converter has the form of a horizontal cylindrical drum, and is usually lined with magnesite brick.

In converting matte is converted to molten copper. It is done in two stages. In the stage-1 air is blown to oxidize all Fe of matte. During blowing of air silica is added to flux the FeO. The reaction is

             

The oxidation of iron sulphide produces enough heat to maintain the temperature of the bath 1300.

After practically all iron is slagged-off more matte is added to the converter and the process is repeated until a sufficiently large amount of copper sulphide is obtained. This is called white metal.

After removal of last slag, blowing is continued to produce molten blister copper. The reaction is

 

The reaction of oxidation of copper sulphide is exothermic. In the converting process no heat supply from outside is needed. The basics of converting operation are illustrated by the following problem;