Question

Which of the following ores are concentrated by Froth Flotation?
\[{\text{A}}{\text{. Oxide ores}}\]
\[{\text{B}}{\text{. Chloride ores}}\]
\[{\text{C}}{\text{. Sulphide ores}}\]
\[{\text{D}}{\text{. Nitride ores}}\]

Answer 1

Hint: There are various methods of concentrating ores. The proper process is selected on the basis of the metal's physical and chemical properties. Froth flotation is mainly used for Sulphide ores. This will help approach the solution to this problem.

Complete step by step solution:

An ore consists of many impurities like sand, gravel, clay, rocks, etc which are known as gangue. Gangues are useless and so we have to remove it from ore. The process of removal of gangue and other impurities from ore is known as concentration of ore.
Froth flotation is a process in which non polar materials are differentiated. For example, copper, zinc, and lead concentration sulphide ores are brought in this process. In this process, oil helps in wetting of ore. The finely ground ore is placed in a tank containing water and 1% of pine oil or turpentine oil. Then strong air current is forced through the suspension, which creates a thick froth or foam on the surface. The metal sulphide gets wet by the oil, but the gangues are not wetted and hence the sulphide-oil mixture is brought to the surface by oil films. In this flotation process, more than 90 % of a sulphide ore can be concentrated to $\dfrac{1}{{10}}{\text{th}}$ of its original content.
Now in this froth floatation process can be used for concentration of only sulphide ores because we can see that only sulphide present in copper, zinc and lead can only be concentrated by this process.
Hence option $C$ is the correct answer and as per this Sulphide ores can be concentrated by the Froth flotation process.

Note: For answering these types of questions we must remember the process of Froth flotation. The first process in the extraction of ore of concentration of ore. And it is the step which mainly involves the removal of dirt. We must remember the main aim of this process.