Abstract
Under conditions relevant to the process of an iron blast furnace with alkali cycling, acid iron ore pellets were tested. The alkalis were introduced in three different ways: as part of the pellets gangue phase, as fine crystals of alkali carbonates near the pellets surface, and, as metal vapor mixed with the reducing gas.
During reduction alkalis flux the silicate binding bridges and react with ferrous iron oxide forming low melting point slag which weakens the pellets and causes them to degrade. A mechanism of degradation will be given which relates the behavior of the pellets to the formation of this primary slag. Also, certain measures to control the reduction will be discussed.
