A converter steelmaking method that blows air or oxygen from the side of the converter wall to refine molten iron into steel. The air acidic side-blown converter is also called Tropenas furnace according to the inventor's surname.
In the 1950s, China's Tangshan Steel Plant successfully tested the alkaline-lined side-blown converter for steelmaking, and it was used throughout China after 1958. The composition changes of the molten pool during the side-blowing converter blowing process are shown in the figure [Composition changes during the side-blowing alkaline converter blowing process].

Since the 1970s, it has been gradually replaced by oxygen converters, mainly oxygen top-blown converters. However, Tangshan Steel Plant developed an oxygen side-blown converter and is used in a workshop of the plant.