METHOD OF CAST IRON MANUFACTURE BY THE ROMELT PROCESS OF LIQUID PHASE RECOVERY Russian patent published in 2017 - IPC C21B11/00 

FIELD: metallurgy.

SUBSTANCE: in the liquid slag bath of the Romelt furnace, iron-containing materials, fluxes and coal fractions of more than 5 mm are simultaneously charged through the upper charging hole. The bubbling of the liquid slag bath and initiation of incomplete coal combustion is achieved by supplying air-oxygen blasting to the lower tuyeres of the Romelt furnace. Oxidation in the afterburn zone of CO and H₂, gases discharged from a liquid slag bath, is carried out by supplying oxygen to the upper tuyeres of the Romelt furnace. The degree of afterburning of gases leaving the liquid slag bath is maintained at 60-85% of the maximum possible degree of afterburning by dividing coal into fractions more 5 mm and less 5 mm. The fraction of coal less than 5 mm is milled to a particle size less than 1 mm and is delivered in a liquid slag bath through the lower tuyeres of the Romelt furnace together with air-oxygen blasting with the intensity of 400-1000 m³/m² of furnace square at the level of the lower tuyeres. The heat flow from the afterburning zone to the liquid slag bath is ensured within the range of 3-6 MW/m² of a liquid slag bath surface.

EFFECT: invention makes it possible to reduce losses of iron with slag and to exclude the possibility of uncontrolled effervescence of the slag bath.

6 cl, 1 dwg, 2 ex, 6 tbl