Patent ID: 7828873

Claim:
A direct smelting vessel for operating a molten bath-based direct smelting process for smelting a metalliferous feed material and producing molten metal under pressure conditions in the vessel, which vessel includes: (a) a hearth adapted to contain a metal layer of the molten bath, the hearth having a base and a hearth side wall; (b) a vessel side wall that extends upwardly from the hearth side wall; (c) a plurality of water-cooled solids injection lances extending downwardly and inwardly into the vessel for injecting solids feed materials into the vessel; (d) at least one water-cooled oxygen-containing gas injection lance extending downwardly into the vessel for injecting an oxygen-containing gas into the vessel; and (e) a forehearth for tapping molten metal continuously from the vessel, the forehearth including: (i) a chamber that can hold a volume of molten metal and has an outlet for discharging molten metal from the chamber, and (ii) an open connection that extends through the hearth side wall to an interior of the vessel and thereby interconnects the chamber and the interior of the vessel, the open connection including a first channel, the first channel having a length of 200 mm to 600 mm that extends from the vessel and a uniform transverse cross-section along its length, the transverse cross-section having a cross-sectional area that is a minimum transverse cross-sectional area of the open connection and that is selected to limit molten metal flow into the forehearth in over-pressure conditions in the vessel and thereby dampen the impact of sudden changes in pressure in the vessel on molten metal flow in the forehearth that could result in an undesirable surge of molten metal from the forehearth, and the open connection also being formed so that molten metal does not freeze in the open connection for at least 6 hours when molten metal is not being discharged from the vessel into the forehearth via the open connection.