Question

Why zinc sulphide is not reduced by self reduction process?

Answer 1

because self reduction process is used for the less electropositive element like Hg, Pb, and Cu. so Zns and Ag2s is not converted by this process

Answer 2

Heya friend!

Zinc sulphide is note reduced by self reduction/autoreduction process because self reduction process is used for the sulphide ores of less electropositive elements like Hg, Pb, and Cu that are heated in air as to convert part of the ore into oxide or sulphate which then reacts with the remaining sulphide ore to give the metal and sulphur dioxide . So,ZnS and Ag2s is not converted by this process .

hope that helps!