Roasting is carried out in extraction of metal in how many ores/minerals?
Chalcopyrite, magnetite, Cassiterite containing impurity of pyrites of Fe and Cu, Galena, Zinc blende, Siderite,

Answer

6

Explanation

`CuFeS_(2)+O_(2)rarrCu_(2)S+FeO +SO_(2)uarr`
`[Fe_(3)O_(4)+O_(4)rarrFe_(2)O_(3)`,
`FeCO_(3)+O_(2)rarrFe_(2)O_(3)+CO_(2)]`
`FeO` conversion into `Fe_(2)O_(3)` to prevent losss of iron in form of slag `(FeSiO_(3))`
`SnO_(2)+O_(2)rarr` No reaction
`{:(FeS),(Cu_(2)S):}}+O_(2)
rarr "sulphate, removed by treating with hot" H_(2)O`
`Pbs + O_(2)rarrPbO+SO_(2)`
`ZnS+O_(2)rarrZnO+SO_(2)`