Question

Froth flotation process which is used for the concentration of sulphide ore:

• A. is based on the difference in wettability of different minerals
• B. uses sodium ethyl xanthate, $C_2{H}_{5}OC{S}_{2}Na$ as collector
• C. uses NaCN as depresent in the mixture of ZnS and PbS when ZnS forms soluble complex and PbS forms froth
• D. All of the above are correct

Answer 1

The correct option is D All of the above are correct

(A) Froth flotation process used for the concentration of sulphide ore is based on the difference in wettability of different minerals.
The metallic sulfide particles of ore are preferentially wetted by oil and the gangue particles by water.
Thus, the option A is correct.
(B) Collectors such as sodium ethyl xanthate $C_2{H}_{5}OC{S}_{2}Na$ are used. pine oils, fatty acids etc. are also used as collectors.
Thus, the option B is correct.
(C) When the minerals are expected to contain PbS and ZnS, suitable depressants such as naCN are added.
The added NaCN, selectively prevents ZnS from coming to the froth by forming soluble complex $N{a}_2\left[Zn\right(CN{)}_4]$ and PbS is separated along with the froth.
Thus, the option C is correct.