Method for extracting zinc oxide from iron-smelting blast furnace fly ash

Abstract

The invention discloses a method for extracting zinc oxide from iron-smelting blast furnace fly ash. Compared with the commonly used rotary furnace process at present, the method has the following advantages that 1, the used fly ash index is wide: the iron content required by the fly ash used by the rotary furnace process is below 20% and the zinc content is above 20%, and iron content required by the fly ash used by the method is not limited and the zinc content is above 6%; 2, fuel addition is not required: 0.45 ton of anthracite or 0.35 ton of coke powder is required to be added in each ton of fly ash in the rotary furnace, and the method does not require fuel addition; 3, the operation cycle is long: the operation cycle of the rotary furnace is 60 days and the operation period of the enclosed furnace in the method is longer than one year; 4, the fireproof material in the furnace is low in cost: the high-temperature wear-resistant fireproof brick used by the rotary furnace costs ** yuan per ton, and the common fireproof brick used in the enclosed furnace costs ** yuan per ton; and 5, the tailing recycle is convenient: the tailings of the rotary furnace process flow out in a liquid state and need to be continuously cooled by water, and contain less iron so that the value in use is low, and the tailings in the method are discharged in a solid state, the tailings with iron content higher than 50% can be directly used in ironworks and the tailings with iron content lower than 50% can be used in cement plants.

Description

technical field [0001] The invention belongs to the technical field of the metallurgical industry, in particular to a method for extracting zinc oxide from waste dust of steelmaking or pig iron. Background technique [0002] The production of ironmaking blast furnace produces a large amount of dust after gas dedusting. The dedusting ash (fly ash) contains 5-20% zinc oxide. Because zinc oxide is cyclically enriched in the ironmaking blast furnace production, it has serious harm to the blast furnace production. Many enterprises treat this part of the dedusting ash as waste. [0003] At present, iron and steel enterprises mainly deal with dust containing zinc oxide: most of them are sold to local brick factories for internal combustion, and a small part of dust containing more than 20% zinc is recycled through rotary kilns. However, due to the high temperature required by the rotary furnace (1300-1400°C), during the production process of the direct extraction of zinc oxide by ...

AI Technical Summary

Problems solved by technology

However, due to the high temperature required by the rotary furnace (1300-1400 ° C), during the production process of the direct extraction of zinc oxide by the rotary furnace, the furnace is easy to form rings and burn and block, resulting in a short production cycle of the rotary furnace and cannot be produced for a long time

More importantly, about 0.4 tons of fuel with a heat capacity of more than 6,000 kcal must be added to each ton of raw materials during rotary kiln production, which consumes a lot of energy and causes serious pollution to the environment.

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