Method of operating in-bath smelting reduction furnace
First Claim
1. In a method of operating an in-bath smelting reduction furnace in the presence of slag wherein oxygen is blown in from a top lance and agitation gas is bubbled through tuyeres located below a metal bath surface, the improvement which comprises controlling the amount of slag present at a weight per unit area of the bath of not less than 2000 kg/m2.
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Abstract
A method of operating an in-bath smelting reduction furnace comprises the step of forming a slag zone in an in-bath smelting reduction furnace supplied with oxygen through a top lance and with agitation gas by bottom bubbling through tuyeres below the metal bath surface, and the step of controlling the carbon material supply rate, the oxygen supply rate and the ore supply rate so as to maintain the apparent density of the slag within a prescribed range.
24 Citations
8 Claims
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1. In a method of operating an in-bath smelting reduction furnace in the presence of slag wherein oxygen is blown in from a top lance and agitation gas is bubbled through tuyeres located below a metal bath surface, the improvement which comprises controlling the amount of slag present at a weight per unit area of the bath of not less than 2000 kg/m2.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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7. A method according to claim 1, wherein the slag contains CaO, SiO2, Al2 O3 and MgO, and the improvement further comprises providing the furnace with a furnace shell lined with refractory, providing the refractory at the upper portion of the furnace with a cooling structure, maintaining the temperature of the metal bath at not more than 1420°
- C., and maintaining a slag composition within the range of CaO/SiO2 =1.1-1.4, Al2 O3 =15-25 wt % and MgO<
13 wt %.
- C., and maintaining a slag composition within the range of CaO/SiO2 =1.1-1.4, Al2 O3 =15-25 wt % and MgO<
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8. A method according to claim 7, wherein ore containing gangue and carbonaceous substances containing ash are present in the furnace, and the improvement further comprises introducing fluxes into the furnace at a ratio of fluxes to the gangue and ash which will maintain the slag composition as defined in claim 7.
Specification