Sulphide ore or a metal is first concerted to it's oxide to extract the metal from it
Answers
Reduction of sulphide ore can be done directly but we generally convert sulphide ore into oxide ore in metallurgical process.
general process- convertion of sulphide ore into oxide ore (we have multiple method to do it) and then followed by reduction.
why we take long route?
reason - COST OF EXTRACTION OF METAL
Condition required for reduction of sulphide ore is not favourable (occurs at high temperature)and not easy to handle ,but conversion of sulphide into oxide ore and reduction of oxide ore to metal is favourable,and effective(less energy required).
Our motive in metallurgy, is to extract metal from ore ,profitably. From sulphide to metal conversion occurs at high temperature so Maintaining high temperature needs more energy souce means more cost. Working at high temperature is also a difficult job
While oxide ore is easily reduced to metal . In metallugry every process occurs on large scale (we are not doing in lab),so cost becomes big factor to choose alternative processes.(sometimes quality and nature is also a factor because different process may give different nature of same metal)
Whole process can be easily understood and explained by the thermodynamics of involving reduction reaction.
Remember ,our main motive is ,to extract metal from ore ,PROFITABLY.
Tedious processes and extreme condition contribute to the cost of extraction.
For every extraction process, generally we have many alternatives but we choose which is cost effective and easy to handle.
For example we can see the extraction of iron from iron pyrites and copper from copper pyrites.