Question

Zinc blende is concentrated by:
(A) Chemical separation
(B) Magnetic speciation
(C) Froth floatation
(D) Hydraulic washing

Answer 1

Hint: We should note here that the zinc blende is concentrated by the froth floatation process as zinc blende is basically the ore of zinc. Others are not as effective as this one and the reasons are given against each one.

Complete step by step solution:
Firstly it is important to note what is zinc blended. So a zinc blender is basically the ore of zinc. It consists largely of the zinc sulphide in crystalline form and variable iron.as we know that the ore is concentrated by froth floatation process and then heated to air to convert zinc sulphide to zinc oxide.
We should note here that the zinc blende is concentrated by the froth floatation process . It is further used for the concentration of the low grade sulphide ores like galena, lead sulphide, copper pyrites. Discussing more about the process we come to know that it is a process which can be selectively used for separating hydrophobic particles from the hydrophilic particles.
Then further we will discuss the other processes also so chemical separation is basically a method that converts a mixture or the solution of chemical substances into two or more product mixtures.
Moreover the magnetic speciation is used to distinguish between the solid mixtures where basically the metals are to be separated.
Lastly we will discuss the hydraulic washing so it is basically a type of gravity separation which is based on gravity differences between the ore and the gangue particles.

Note:
As all the methods have its own significance . but about the froth floatation this was the first used in the mining industry, where it was one of the great enabling technologies of the twenty century.