Question

Name the method used for separation of sulphide ores?

• A. Hydraulic washing
• B. Magnetic separation
• C. Froth floatation
• D. Leaching

Hint:

Sulphide ores are generally concentrated by froth flotation because sulphide particles are preferentially wetted by oil.

Answer 1

The Correct Option is C

Concept:
The concentration of ores means removal of unwanted impurities called gangue from the ore. Different ores are concentrated by different methods depending on their physical and chemical properties. Sulphide ores are commonly concentrated by froth flotation.

Step 1: Understand froth flotation.
In froth flotation, powdered sulphide ore is mixed with water and collectors. Air is blown through the mixture. Sulphide ore particles attach to air bubbles and rise as froth. Gangue particles remain in water.

Step 2: Why sulphide ores use this method.
Sulphide ores are preferentially wetted by oil. Gangue particles are wetted by water. This difference helps separate sulphide ore from impurities.

Step 3: Check the options.
Option (A) Hydraulic washing is based on density difference and is not the common method for sulphide ores.
Option (B) Magnetic separation is used when ore or gangue is magnetic.
Option (C) Froth floatation is correct for sulphide ores.
Option (D) Leaching is used for some ores like bauxite, silver, and gold ores. Hence, the correct answer is: \[ \boxed{(C)\ \text{Froth floatation}} \]