Device and method for smelting iron by low-grade limonite ore

Abstract

The invention discloses a device and method for smelting iron by low-grade limonite ore. The device comprises a hot blast furnace, an ore roasting furnace, a lime stone calcining furnace and a blower, wherein the ore roasting furnace and the lime stone calcining furnace are respectively arranged at the left side and the right side of the hot blast furnace; the upper part of the gas burning chamber of the hot blast furnace is connected with the lime stone calcining furnace through a high-temperature flue gas channel; and the top of the hot blast furnace is connected with the ore roasting furnace through a waste heat flue gas channel. In the method, the gas in the gas burning chamber and the air sucked into an air inlet and a furnace charge adding port are mixed and burnt, the generated high-temperature flue gas heats the air in a heated air pipe, and partial high-temperature flue gas is sucked into the lime stone calcining furnace through the high-temperature flue gas channel to calcine the lime stone; and residual waste heat flue gas rises to the top of the hot blast furnace, the temperature of the waste heat flue gas is 750-850 DEG C, and the waste heat flue gas is sucked into the ore roasting furnace through a waste heat flue gas channel to dry and roast the ore. In the invention, the limonite ore which is widely distributed in the natural world and has low smelting value can be used for smelting iron with low cost.

Description

technical field [0001] The invention relates to an ironmaking device and method, in particular to a low-grade limonite ore ironmaking device and method for effectively utilizing the most widely distributed limonite ore with low smelting value in nature. Background technique [0002] Limonite is a hydrous iron oxide ore, which is formed by the weathering of other ores and is the most widely distributed in nature. Abundant reserves. Low-strength (iron-containing<50%) limonite ores are largely undeveloped due to their low smelting value. [0003] Modern airtight blast furnace ironmaking technology has been very mature after decades of development and research, but there are still many problems that are difficult to solve when using low-grade limonite ore directly into the furnace for smelting, such as high energy consumption, low blast furnace utilization factor, and pig iron production. Low, difficult to operate, etc. It is mainly caused by the characteristics of low-gra...

AI Technical Summary

Problems solved by technology

But modern closed ironmaking blast furnaces cannot adapt to this method of ironmaking

The main reason is that when quicklime is added to the furnace, more water vapor in the gas will react with the lime to pulverize a small amount of lime, so that the gas dust contains an excessive amount of calcium oxide ions, and the calcium oxide ions and water vapor, etc. The reaction is prone to fouling and a series of problems such as gas pipeline blockage

In addition, the use of hot ore in a closed blast furnace is prone to danger. When the temperature of the hot ore is higher than 550°C, it is easy to ignite the gas and cause accidents when feeding materials. Therefore, this ironmaking method is not suitable for modern closed blast furnaces.

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