Smelting reduction iron-making device and method for avoiding re-oxidation of pre-reduction ores

Abstract

The invention discloses a smelting reduction iron-making device and method for avoiding re-oxidation of pre-reduction ores, and belongs to the technical field of smelting reduction iron making. The smelting reduction iron-making device adopts an existing shaft furnace and an iron bath furnace as reduction reactors and also comprises a feed port which is used for conveying pre-reduction ores generated by the shaft furnace to the furnace body side surface of the iron bath furnace by adopting a pre-reduction furnace charge descending passage, the furnace charge is further pressed into a slag blanket of the iron bath furnace to avoid the pre-reduction ores from contacting with gas in a free space in the upper part of the iron bath furnace and generating re-oxidation, thereby ensuring that the secondary combustion rate of the gas in the free space is not limited. Three layers of spray guns are arranged on the furnace body of the iron bath furnace, and the secondary combustion rate and the temperature of the gas in the furnace can be adjusted by adjusting the oxygen blowing ratio and the coal injection ratio as well as the total oxygen blowing quantity and the total coal injection quantity of the three layers of the spray guns, thereby providing sufficient heat for a melting bath in the iron bath furnace.

Description

technical field [0001] The invention belongs to the technical field of smelting reduction ironmaking, and in particular provides a smelting reduction ironmaking device and method for avoiding re-oxidation of pre-reduced ore. Background technique [0002] The main direction of the development of smelting reduction ironmaking technology is to replace coke with coal and directly apply fine ore resources to achieve the goals of making full use of resources, shortening the process, reducing investment, reducing costs and reducing environmental pollution. According to the degree of pre-reduction of iron-containing raw materials, the smelting reduction ironmaking process can be divided into one-step method and two-step method. The one-step method is to melt the iron-containing raw materials first and then reduce them, such as the Romelt process and the HIsmelt process; the two-step smelting reduction method first pre-reduces the iron ore in a shaft furnace or a fluidized bed, and t...

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Problems solved by technology

[0003] The disadvantages of the one-step method are: first, the molten iron oxide is highly corrosive, which seriously damages the furnace lining and shortens the service life; second, the reduction produces high-temperature gas above 1500°C and excessive CO, and the heat carried by the gas cannot be effectively transferred To the reduction zone, the heat utilization rate of the gas is low

However, the common disadvantage of these two processes is that in order to avoid the re-oxidation of the pre-reduced ore, the secondary combustion rate of the gas in the final reduction furnace is very low, such as less than 10%, resulting in a high fuel ratio.

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