ANS:C - Balling

Balling, in the context of ore processing, refers to a process of forming small spherical balls or pellets from fine particles of ore. This process is a type of agglomeration, where individual particles are bound together to form larger, more uniform aggregates. Balling is commonly used in the preparation of iron ore for downstream processing in the steelmaking industry, but it can also be used for other types of ores. Here's how the balling process typically works:

1. Particle size reduction: Before balling can occur, the raw ore must undergo crushing and grinding to reduce its particle size. The ore is typically ground to a fine powder to increase its surface area and improve its reactivity.
2. Agglomeration: Once the ore particles are finely ground, they are mixed with binders, such as bentonite or organic binders, and sometimes water, to form a moistened feed mixture. The binders help to bind the particles together and provide strength to the formed balls.
3. Formation of balls: The moistened feed mixture is then fed into a balling device, such as a balling drum or disc pelletiser. Inside the balling device, the feed mixture is agitated and tumbled, causing the particles to adhere to one another and form small spherical balls or pellets. The rotation of the balling device helps to shape the pellets and ensure uniformity in size and shape.
4. Drying and curing: Once formed, the pellets may undergo a drying process to remove excess moisture and strengthen the bonds between particles. This can be done in a separate drying apparatus or within the balling device itself. After drying, the pellets may be further cured or hardened through heat treatment or chemical processes, depending on the specific requirements of the application.
5. Storage and transportation: The finished pellets are then ready for storage, transportation, or further processing. The spherical shape of the pellets and their uniform size make them easier to handle, transport, and charge into blast furnaces or other processing equipment.

Overall, balling is an important step in ore processing, particularly for iron ore, as it improves the efficiency of downstream processing and enhances the quality of the final product. It allows for the transformation of fine ore particles into larger, more manageable forms that are better suited for handling, transportation, and metallurgical processing.