Question:
Which of the following ore is concentrated using group 1 cyanide salt?
Correct Option: 1
Solution:
Conc. of sphalerite, first by cyanide salt as a depressant to remove the impurity of galena
$\mathrm{Zns}+\mathrm{Pbs}+\mathrm{NaCN} \longrightarrow \mathrm{Na}_{2}\left[\mathrm{Zn}(\mathrm{CN})_{4}\right]+\mathrm{PbS} \uparrow$