Question

Which of the following pair of ores cannot be converted into corresponding metals by pyrometallurgy?

• A. ${\mathrm{Ag}}_2\mathrm{S},\mathrm{ZnS}$
• B. ${\mathrm{Cu}}_2\mathrm{S},\mathrm{HgS}$
• C. ${\mathrm{MnO}}_2,{\mathrm{SnO}}_2$
• D. None of this

Answer 1

The correct option is A

${\mathrm{Ag}}_2\mathrm{S},\mathrm{ZnS}$

Explanation for the correct option

(A)${\mathrm{Ag}}_2\mathrm{S},\mathrm{ZnS}$

Pyrometallurgy

• A subfield of extractive metallurgy is pyrometallurgy. It entails heating minerals, metallurgical ores, and concentrates to cause physical and chemical changes in the materials that allow for the recovery of valuable metals.
• A zinc blende $\left(\mathrm{ZnS}\right)$ is a thermally stable zinc blende that does not undergo auto reduction. Roasting converts it to oxide ore, which is then transformed to the required metal. The same may be said for element ${\mathrm{Ag}}_2\mathrm{S}$.
• So, ${\mathrm{Ag}}_2\mathrm{S},\mathrm{ZnS}$ can not be converted to corresponding metals by pyrometallurgy.

Explanation for incorrect options

• Pyrometallurgical treatment can lead to commercially viable products such as pure metals or intermediate compounds or alloys that can be used as feedstock for further processing.
• Other given pairs can be converted to corresponding metals by pyrometallurgy.
• Therefore, options (B), (C), and (D)are incorrect.

Hence, option (A) is correct. ${\mathrm{Ag}}_2\mathrm{S},\mathrm{ZnS}$ can not be converted to corresponding metals by pyrometallurgy.