Direct smelting process

A direct smelting process in a direct smelting vessel that includes;

• (a) injecting iron ore and a solid carbonaceous feed material into a molten bath comprising a layer of molten metal and a layer of molten slag, so as to deliver at least part of the iron ore and the solid carbonaceous feed materials into the metal layer and thereby direct smelting of the iron ore to molten iron, generating reaction gases from smelting reactions in the molten bath which cause molten metal and/or slag to be projected into a gas space above the surface of the molten bath and to form a transition zone,
• (b) injecting an oxygen-containing gas into the gas space to cause post-combustion of the reaction gases, whereby heat generated by post-combustion is transferred to the molten bath by heating the molten metal and the molten slag in the transition zone, and
• (c) producing process outputs of molten iron, molten slag, and an off-gas, and the process being characterised by:
• (i) controlling the slag composition with respect to an FeO content and additive content and the temperature of the molten bath to be below the liquidus temperature of the slag so that a solid oxide phase precipitates from a liquid phase of the molten slag, whereby the slag is a slurry of a solid material and a liquid phase, the solid material is at least 5 vol. % and less than 30 vol. % of the molten slag, and the molten slag has a viscosity in a range of 0.5-5 poise in an operating temperature range for the process;
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• (ii) controlling the injection of the solid carbonaceous feed materials and a carrier gas, to produce substantial agitation of the molten bath such that there is a substantial uniform temperature in the molten bath;
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• (iii) controlling the injection rate of the iron ore feed material and the solid carbonaceous feed material so that a FeO content of the molten slag is at least 3 wt. % and less than 10 wt. %.