Process for treating top gas of reduction shaft furnace

Abstract

The invention belongs to the metallurgical chemical technology, and relates to a process for treating top gas of a reduction shaft furnace. The treatment process is characterized in that after the top gas exhausted from the reduction shaft furnace is subjected to dust removal and cooling treatment, the top gas enters a carbon removal system to remove CO2 in the gas; and one part of the carbon removal gas after carbon removal and compression is directly mixed with the high-temperature gas exhausted from a smelting gas-making furnace to enter the reduction shaft furnace, and the other part of the carbon removal gas is heated and then enters the reduction shaft furnace. The process for treating the top gas of the reduction shaft furnace has the advantages of reasonable flow, optimized energy conservation and discharge reduction and technical domestication, and can be used for an iron-making process of an SDRF furnace.

Description

technical field [0001] The invention belongs to the metallurgical chemical technology category, and relates to a reduction shaft furnace top gas treatment process, in particular to a reduction shaft furnace top gas treatment process for an SDRF furnace ironmaking process. technical background [0002] The SDRF furnace ironmaking process is a new type of ironmaking technology developed by China Metallurgical Saidi Engineering Technology Co., Ltd. It consists of a smelting gas furnace, a reduction shaft furnace, and a gas treatment system. The SDRF furnace is a production of hot metal. It also produces sponge iron, and a new ironmaking process suitable for gas output that is environmentally friendly, energy-saving, and water-saving. [0003] The SDRF furnace ironmaking process involves major issues such as gas backflow at the top of the reduction shaft furnace, gas heat energy, and pressure energy recovery. The gas process is a key component of the entire process. The key of ...

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Problems solved by technology

The key of the SDRF gas process is to use the method of recirculation of the top gas of the reduction shaft furnace to completely recover the heat of the gas at the outlet of the smelting gas furnace, and to use dry dust removal for the top gas of the reduction shaft furnace. The lack of consideration of heat and pressure energy recovery of the furnace top gas is mainly reflected in the following points: 1) The gas outlet of the reduction shaft furnace top has a relatively high temperature, and it needs to be cooled before entering the dry dust removal process, which was not considered in the original process The heat energy recovery of this part of the gas cooling: 2) The original process uses the gas tank to regulate the pressure fluctuation of the pipe network. The storage pressure of the gas tank is low, so that the gas needs to be expanded and depressurized before entering the gas tank. After expansion, it enters the decarbonization system. out of CO 2 It needs to increase the pressure and lower the temperature to meet the entry temperature and pressure requirements of the decarbonization system. Such a treatment process leads to an increase in energy consumption, water consumption and investment, and does not make full use of the pressure of the reduction shaft furnace top gas itself; 3) the original The process uses a hot blast stove to heat part of the reducing gas entering the reduction shaft furnace. The heating speed of the hot blast stove is slow, the investment is high, and the waste gas emitted by heating is more

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