Comprehensive treatment method of dry reclaimed dust of blast furnace

Abstract

The invention relates to a comprehensive treatment method of dry reclaimed dust of a blast furnace. The reclaimed dust mainly comprise the following ingredients: 15-25% of TFe, 14-30% of C, 4-6% of Zn, 5-7% of alkali metal salt, 0.5-1.9% of cyanide, 8-10% of SiO2, 2-3% of Al2O3, 15-21% of CaO and MnO, and small amounts of combined-state Pb and Cu or simple substances Pb and Cu. The technological process comprises the steps of unloading the dust, mixing, carrying out ball milling, performing flotation, reselecting and carrying out water treatment. After the method is applied to the dry reclaimed dusts of the blast furnace, environment-protection indexes reach the standard, and the contents of alkali metal, lead and zinc entering ore matching for sintering directly can be reduced greatly; the yield of fine powdered iron in dry reclaimed dusts is improved by 5-10%, the yield of the recycled carbon dusts is improved by 8-10% and the equipment failure rate is reduced remarkably.

Description

technical field [0001] The invention belongs to the technical field of comprehensive utilization of resources and environmental protection, and in particular relates to a comprehensive treatment method of blast furnace dry dust removal ash. Background technique [0002] Steel mills usually perform dry dust removal on blast furnace gas ash, gas mud, etc., to obtain a dry dust removal ash (referred to as "dry ash"). Taking an iron and steel group as an example, this blast furnace dry dust removal ash contains 5.0%~7.0% alkali metal salts, 4.0%~6.0% zinc content, and 0.05%~0.19% cyanide content. It will increase the alkali metal load and zinc load of the blast furnace, which is extremely unfavorable for the forward run of the blast furnace. [0003] The prior art generally adopts the method of beneficiation of circulating water for this dust removal, which will cause the circulating water to be continuously concentrated and enriched, and the salt, CN in the system. - The incr...

AI Technical Summary

Problems solved by technology

Taking a certain iron and steel group as an example, the blast furnace dry dedusting ash contains 5.0%~7.0% of alkaline metal salts, 4.0%~6.0% of zinc, and 0.05%~0.19% of cyanide. It will increase the alkali metal load and zinc load of the blast furnace, which is extremely unfavorable to the forward movement of the blast furnace

[0003] The existing technology generally adopts the method of circulating water beneficiation for this kind of dust removal, which will make the circulating water continuously concentrated and enriched, and the salt content, CN - The content rises, and the pH value increases, which is a big hidden danger to the surrounding environment, and the beneficiation system is greatly affected due to the high alkalinity of the water quality

The salt and cyanide ions in the iron-containing materials are dissolved in the circulating water, resulting in high salt and cyanide ions in the system

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