Iron ore pellets are indurated, spheres of ore with a high iron content and uniform quality. Peller plants can produce two varieties of pellets: blast furnace pellets and direct reduction pellets (DR pellets). Blast furnace pellets are used in the coke-based blast furnace process, which is the most common method of producing hot metal (molten iron for steelmaking). Blast furnace pellets are delivered mainly to steel mills. DR pellets are used in the direct reduction processes to produce sponge iron, which is an alternative process route, as an initial stage from iron to steel. The DR process is primarily based on the use of natural gas and has become increasingly common in countries with access to inexpensive natural gas.