Question

What is the role of collectors in froth floatation?

Answer 1

Hint:
The process of extraction of a metal in the free state from its ores is referred to as metallurgy. The three steps involved in metallurgy are:
Concentration or beneficiation of the ore,
Production of metal from the concentrated ore and
Purification of the crude metal.

Step-by-step explanation:
Step 1:
The process of removal of gangue (waste material) from the ore is called concentration or dressing or beneficiation of the ore.
Step 2:
The various methods of concentrating an ore are:
Hydraulic washing
Magnetic separation
Froth floatation
Leaching
Step 3:
Froth floatation method is used for the concentration of those ores in which ore particles are preferentially wetted by oil whereas the gangue particles by water.
The following substances are added in the slurry of the finely divided ore and water:
Frothing agents like pine oil or eucalyptus oil
Collectors like ethyl xanthate or potassium ethyl xanthate and
Activators.
Step 4:
Ethyl xanthate or potassium ethyl xanthate are used as collectors which increases the binding force between the ore particles and the froth. Thus, the ore particles become water repellent and pass on into the froth. So, the ore particles get transferred into the upper layer along with the froth while the impurities settle down in the bottom.

Hence, the collectors help the ore to bind with the froth and get transferred into the upper layer while the impurities settle down in the bottom.

Note: The froth floatation method of concentration of ores is extensively used for the concentration of the sulphide ores.