The smell of rotten egg is given by sulphide ores only because the sulphur has the characteristic smell of rotten egg.
The sulphide ores are concentrated by froth floatation method. The metals are obtained from the conc. ores by using pyrometallurgy, or smelting at high temperature, in which process the sulfur in the metal sulfide is oxidized with air or oxygen to sulfur dioxide, and molten metal is produced.