Question

Froth floatation process is used to concentrate magnetic ores.
A. True
B. False

Answer 1

Hint: To answer this question, you must recall the process and principles of the froth floatation process. It is a process used for the selective separation of hydrophobic substances from hydrophilic ones. It has various applications in refining of ores in metallurgy, paper recycling and waste water treatment.

Complete step by step answer:
- The froth floatation process is used mainly for the concentration of sulphide ores. In the froth floatation process, the ore to be concentrated is crushed and added in water. Air is then passed into the suspension using a motor. To this mixture, we further add pine oil which works as a collector and selectively wets the hydrophobic ore particles. Whereas water wets the hydrophilic gangue particles or the impurities.
- When air is passed through the mixture, the particles wetted by the collector being lighter rise up to the top and float and act as froth. The froth is then skimmed from the mixture separating it from the gangue. On drying, we obtain concentrated ore which can now be refined easily.
- This method is used in the metallurgy industry and separates particles of interest physically from a liquid based mixture depending on their ability to adhere to air bubbles selectively. In other words we can say that the particles are separated based upon their hydrophobic character. Thus, it cannot be used to concentrate magnetic ores.
Thus, the given statement is false.

Thus, the correct option is B.

Note:
To separate magnetic ores, a different technique is used which is known as magnetic separation. Powdered ore is put on a moving conveyor belt that moves over two magnetic rollers. The magnetic particles are attracted by the rollers and stick to it while the non- magnetic particles are not attracted by the roller and are separated.