I would appreciate a bit more discussion on how sulphide ore is...

I would appreciate a bit more discussion on how sulphide ore is processed.

Doing a google search on extracting gold from sulphide ore comes up with the following:

The gold-bearing mineral in the high sulfide ore is enriched into the concentrate by flotation, and then slaked lime and additives are added to the flotation concentrate, and the mixture is roasted after being thoroughly mixed. The roasting temperature is generally controlled at about 650 ° C.17 Mar 2020

Guides For High-sulfide Gold Processing

Some posters saying that an oxide plant is hard to convert to sulphide processing.
It seems that a roasting plant would need to be added - and that does not sound cheap to me.