What is the primary use of a cupola in metalworking?

The primary use of a cupola in metalworking is to melt cast irons. A cupola is a vertical, cylindrical furnace that operates continuously and is primarily designed for melting ferrous metals, particularly cast iron. It is charged with layers of metal scrap, coke (as fuel), and limestone (as flux), and as the materials descend, they undergo a combustion and melting process due to the intense heat generated in the furnace.

The cupola's design allows for efficient melting and continuous operation, enabling metal foundries to produce large quantities of molten iron, which can then be poured into molds for casting. This makes it a crucial piece of equipment in the foundry industry where cast iron parts are produced.

The other options pertain to different processes in metalworking. While shaping, cooling, and refining metals are essential steps in metal processing, they do not specifically relate to the primary function of a cupola, which is focused on melting.