The reverse process of fractional crystallisation is called

ANS:B - leaching

The reverse process of fractional crystallization, where a solvent is added to dissolve the solute, is known as "leaching." Leaching involves extracting a soluble component from a solid mixture by dissolving it in a liquid phase. This process is commonly used in various industries, including mining, metallurgy, and agriculture, to separate desired components from raw materials or waste products.