Oxygen-free cooling and residual heat recovering method for magnetizing-roasted iron ore product

Abstract

The invention relates to the technical field of metallurgy, in particular to an oxygen-free cooling and residual heat recovering method for a magnetizing-roasted iron ore product. The method comprises the following steps: feeding a magnetizing-roasted high-temperature material being 800-850 DEG C and 8-25 millimeters in granularity from the upper part of a vertical cooler; introducing blast furnace gas of which the CO or H2 volume content is not greater than 30 percent from the lower part of the vertical cooler, and controlling the flow rate of the high blast coal gas at 0.8-1.5 m / s; performing heat exchange between the high-temperature material and the blast coal gas in the vertical cooler during inverse flow, wherein the temperature of the high-temperature material is lowered below 200 DEG C, and the temperature of the blast coal gas is raised to 700-750 DEG C. The magnetizing-roasted high-temperature material undergoes secondary oxidation in a cooling process, and can undergo secondary micro-reduction in the cooling process in the cooler, so that the quality of the magnetizing-roasted iron ore product is improved. Meanwhile, the over-reduction of the material is prevented, and cyclic utilization of residual heat is realized.

Description

technical field [0001] The invention relates to the technical field of metallurgy, in particular to a method for anaerobic cooling and waste heat recovery of iron ore magnetized roasting products. Background technique [0002] In the traditional iron ore magnetization roasting process, high-temperature materials are generally directly put into water for cooling. During the cooling process of high-temperature materials in contact with water, the micro-oxidation of the reduced materials will be caused, and the metal after magnetization and roasting of iron ore will be caused. The recovery rate has a certain impact. This high-temperature material cooling method not only causes the loss of waste heat of the material and the increase of production water consumption, but also produces dusty steam during the material cooling process, which will cause certain environmental pollution. [0003] In the iron ore magnetization roasting furnace, in order to enhance the radiation heat t...

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Problems solved by technology

[0002] In the traditional iron ore magnetization roasting process, high-temperature materials are generally directly put into water for cooling. During the cooling process of high-temperature materials in contact with water, the micro-oxidation of the reduced materials will be caused, and the metal after magnetization and roasting of iron ore will be caused. The recovery rate has a certain impact. This method of cooling high-temperature materials not only causes the loss of waste heat of the materials and the increase of production water consumption, but also produces dusty steam during the material cooling process, which will cause certain environmental pollution.

[0003] In the iron ore magnetization roasting furnace, in order to enhance the radiation heat transfer in the furnace, the furnace temperature is generally raised by burning gas with high calorific value at room temperature. Because of the low theoretical combustion temperature of blast furnace gas, it cannot meet the heating requirements of the iron ore magnetization roasting furnace. needs, and there is a phenomenon of low utilization rate in iron and steel enterprises, and when using traditional tubular heat exchangers and other equipment for gas preheating, due to the heat-resistant temperature limit of the equipment itself, it cannot meet the heating needs of the magnetization roaster , the equipment composition is relatively complex, which affects the production cost of waste heat recovery of high-temperature roasting materials