Iron mine sintering flue gas segmented circulation method

Abstract

The invention discloses an iron mine sintering flue gas segmented circulation method. Sintering flue gas high in O2 content on the tail portion of a sintering machine is circulated to the interior of a head flue cover of a sintering feed surface of the head portion of the sintering machine, flue gas of two to three bellows highest in SO2 content in a bellow on the tail portion of the sintering machine is conveyed to a desulfurization system to be desulfurized, and flue gas in other bellows is circulated to a middle flue cover of a sintering feed surface of the middle portion of the sintering machine. After segmented flue gas circulation is adopted, SO2 will not be accumulated in sintering ore, dust emission is reduced by 20-40%, NOx emission is reduced by 20-40%, dioxin emission is reduced by 50-80%, and CO2 emission is reduced by 20-45%.

Description

technical field [0001] The invention relates to a method for iron ore sintering, in particular to a method for reducing emission of sintering pollutants by flue gas circulation. Background technique [0002] The iron and steel industry is a typical high-energy-consuming and high-pollution industry, and its energy conservation and emission reduction are of great practical significance to the sustainable development of my country's national economy. The ironmaking system of my country's iron and steel industry is dominated by the sintering-blast furnace process, and sinter is the main charge of blast furnace ironmaking, accounting for about 75% in my country. The energy consumption of the sintering production process is high, and the flue gas emitted during the sintering process contains dust, COx, SOx, NOx, and highly carcinogenic substances such as dioxins and furans, and also emits various pollutants such as acid gases, heavy metals, and alkali metals. Due to its large amo...

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Problems solved by technology

The current cycle process mostly uses one cycle, and it is difficult to achieve the maximum comprehensive emission reduction of various pollutants under the condition that the sinter is not enriched in sulfur

For example, the LEEP process and the EPOSINT process mainly circulate the flue gas at the tail of the sintering machine, because the SO in the flue gas at the middle tail 2 High concentration, SO 2 It is easy to be adsorbed in the sinter during the circulation process and lead to sulfur enrichment; while the circulation technology of Nippon Steel and Baosteel only circulates the high-temperature flue gas at the tail of the sintering machine, and contains high SO 2 , Dioxins / furans, PAHs, heavy metals, etc., have not been effectively treated. Even with desulfurization purification technology, dioxins / furans, PAHs, and heavy metals are easily adsorbed in desulfurization by-products and cause environmental pollution.

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