The process of this furnace is based on flash fusion, which tries to suspend and melt the dry charge in a vertical or horizontal flow of air, enriched with oxygen. The molten material that is formed in the reaction tower is collected in the separation chamber where the shaft is separated from the slag by the specific weight difference.
It needs a refractory material with low porosity, high density to avoid the chemical attack suffered by SiO2, high resistance to abrasion caused by waste gases.