Solution: 

Basis 1000 kg copper concentrate.

Weight of roasted product can be determined easily, it is 773.6 kg (a) Ans.

Sulphurin roast product (b)Ans.

Flue gas analysis is not known. Problem states that flue gas contains  which suggests that excess air is used.

From the problem S oxidized =9.04 kg mols

One can calculate theoretical amount of oxygen by considering that S is oxidized to  is oxidized to . Amount of  have already been determined.







Theoretical oxygen = 49.632 kg mole

Let Z kg mole is flue gas; Amount of .

This excess oxygen coming from air will also contain 0.451Z excess .

Now the flue gas contains excess  theroctical excess oxygen  =  Z



Excess air  (c) Ans.

Composition of flue gas .