Back to results
US 4,304,597 AGranted
System for control of sinter formation in iron oxide reducing kilns
AssigneeThe Direct Reduction Corporation
InventorsVitie P. Keran, Alan C. Baker
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeThe Direct Reduction Corporation
InventorsVitie P. Keran, Alan C. Baker
Estimating the term…
A method and means for improving control of the process for directly reducing ores containing iron oxide in a rotary kiln using a solid carbonaceous reducing agent, such as coal, introduced from the ore feed and discharge ends of the kiln, as both fuel and reductant, is disclosed wherein the temperature profile of the moving bed of solids is maintained such that the temperature is moderated to remain below the sintering temperature of the materials in the bed from the feed end zone for about the first two-thirds of the kiln length and the temperature is then maximized within sintering limitations in the working zone which is limited to about the last third of the kiln length. The temperature profile is controlled by regulating the volumes of air supplied to the kiln atmosphere from air injectors at spaced intervals along the length of the kiln, after establishing the appropriate proportion of coal steadily blown into the discharge end of the kiln for the particular process constituents being used.
In the process for reducing ore containing iron oxides using a solid carbonaceous reducing agent as the source of fuel and reductant in a rotary kiln fitted with air injection devices spaced along its length for injecting air axially therein, and wherein the reducing agent forms with the ore and other solid constituents added to the kiln a moving bed of solids therein, the improvement comprising maintaining the temperature profile of the bed of solids in the kiln such that the maximum possible temperature for non-sintering of the constituents occurs in the bed only in approximately the last third of the kiln and the temperature is moderated in the remainder of the bed to below said non-sintering temperature.
A method for controlling sinter formation in a rotary kiln directly reducing ore containing iron oxides using at least one solid carbonaceous material as the source of fuel and reductant, which kiln is fitted along its length with combustion-supporting gas injection devices for injecting said gas axially therein and with temperature-sensing devices and has a preheat zone toward the charge feed end and a working zone toward the discharge end, comprising the steps of:
Dependencies are inferred from the claim text.