Method for comprehensively utilizing electric field dust-removal ash at head end of sintering machine and blast furnace gas ash

Abstract

The invention belongs to the field of ferrous metallurgy and environmental protection and particularly relates to a method for comprehensively utilizing electric field dust-removal ash at a head end of a sintering machine and blast furnace gas ash. By-products generated in two metallurgical production processes, namely, electric field dust-removal ash at an electrical dust remover located at the head end of the sintering machine and blast furnace gas ash have different contents of potassium salt, iron metal compounds, carbon nonmetal elementary substance, heavy metal compounds of lead and zinc, however, the chemical compositions of the by-products are complementary, by virtue of scientific and reasonable combination and matching of two materials, certain process conditions and recovery methods, iron-containing compounds and potassium salt in the two iron and steel smelting by-products are recovered, heavy metal compounds of lead and zinc are separated so as to achieve the efficient recycling and comprehensive utilization of multiple elements in two solid wastes and meet the requirements of resourceful treatment of the solid wastes, energy conservation and emission reduction.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgy and environmental protection, and specifically relates to the treatment and utilization technology of the gas ash collected by the dry-process bag filter of the blast furnace of the iron and steel plant and the solid waste of the sintering head of the iron and steel plant, and especially a sintering head electric field A method for comprehensive utilization of dedusting ash and blast furnace gas ash. Background technique [0002] my country's steel production is dominated by the blast furnace-converter long process, and iron ore sintering is an important link in steel production. [0003] The sintering head electric field dust is referred to as sintering ash, which is the dust collected by the sintering head flue gas electric dust collector during the iron ore sintering process. In the process of iron and steel production, sinter accounts for about 70%-75% of the blast furnace charge, and...

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Problems solved by technology

[0007] (1) When the sintered ash is recycled as an iron ore sintering ingredient, the alkali metal element compound in it is enriched in the sintered ash, and the high content of the alkali metal compound increases the resistance of the sintered powder particles with a submicron particle size structure , leading to a decline in the collection and removal efficiency of the electrostatic precipitator at the sintering head and a deterioration in the operational stability of the dust removal device, resulting in the excessive concentration of smoke and dust emitted by the electrostatic precipitator at the sintering head and an increase in the operating energy consumption of the dust removal device

[0008] (2) K in the dust removal dust of sintering machine heads in domestic iron and steel plants 2 The O content is more than 10%, and my country is a country lacking in potassium salt resources, K 2 O The economic reserves are only 8 million tons, accounting for about 2.5% of the world, and the self-sufficiency rate is less than 60%. Since sinter ash contains a small amount of heavy metal elements such as lead, zinc, and copper, these heavy metal elements enter the ironmaking blast furnace with iron ore and are Circulating and enriching in the furnace, forming nodules in the blast furnace, blocking the blast furnace gas dust removal system pipeline, causing difficulty in blast furnace ignition, and reducing the blast furnace charge strength, the blast furnace condition is easy to fluctuate, and it is easy to cause blast furnace shutdown and production accidents

[0016] Therefore, the existing method of directly recycling blast furnace gas ash cannot completely solve the problem of gas ash disposal

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