Iron-containing zinc powder recycling process

A technology of dust recovery and process, which is applied in the field of recycling and utilization of iron and zinc dust produced in iron and steel process, and can solve problems such as blockage of smoke exhaust channels, high coke ratio, high S and P content in molten iron, etc.

CN104073649AInactive Publication Date: 2014-10-01WISDRI ENG & RES INC LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2014-10-01
Estimated Expiration
Not applicable · inactive patent
Patent Text Reader

Abstract

The invention discloses a recycling process of iron-containing zinc powder generated in an iron and steel process. The process comprises the following steps: mixing dried iron-containing zinc powder with a binder, and pelletizing by a pelletizer to obtain green balls; feeding the green balls into a shaft furnace and heating to 1100-1300 DEG C; reducing iron in the shaft furnace to sponge iron; converting reduced zinc at high temperature into zinc steam which is discharged out of the shaft furnace with coal gas and enters into a two-stage dedustor; and feeding dedusting mud obtained from the dedustor into a settling pond, and filtering, settling, thickening and drying to obtain zinc powder. The iron-containing zinc powder mainly comprises blast furnace gas ash, gas mud, dedusting ash, converter steelmaking dust and continuous casting steel rolling scrap iron generated in the iron and steel production. By adopting a treatment mode of the shaft furnace, the problem such as large rotary kiln equipment, low utilization ratio of in-kiln volume and high energy consumption is solved. Coal base is directly reduced at a high speed, and meanwhile, zinc in dust is further recovered.
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Description

technical field

[0001] The invention belongs to the technical field of iron and steel production, and in particular relates to a recycling method for dust containing iron and zinc produced in the iron and steel process. Background technique

[0002] With the development of my country's iron and steel industry, the impact of dust generated in the process of iron and steel production on the environment has become increasingly prominent. Generally speaking, the amount of dust in iron and steel enterprises is 8% to 12% of steel production. The annual dust output of iron and steel enterprises in my country reaches tens of millions of tons. These dusts contain a large amount of iron, as well as carbon, zinc, lead, potassium and other elements. .

[0003] Usually, iron and steel enterprises collect these dusts and use them as sintering raw materials for recycling within the enterprise. Due to the fine particle size and large specific surface area of ​​these dusts, the addition of ...

Examples

Embodiment 1

[0029] 1) Recycling and drying iron and zinc-containing dust in iron and steel plant;

[0030] 2) Mix the dried dust with coal powder and binder in proportion, the ratio of dust to coal powder is C / O=1.1, and the ratio of binder is 2%;

[0031] 3) Pellet the mixed dust on a pelletizing machine to obtain raw pellets, the diameter of which is about 25mm, plus or minus 5mm;

[0032] 4) The raw pellets are fed into the shaft furnace, and are gradually heated to 1200°C by the gas rising from the bottom from top to bottom, and a self-reduction reaction occurs. 3 above;

[0033] 5) Zinc is reduced in the lower part of the blast furnace to form zinc vapor, which together with the rising gas is discharged from the shaft furnace at 300°C and enters the two-stage dust collector;

[0034] 6) The gas carrying zinc vapor enters the heat exchanger after the initial dedusting, and the heat generated by the heat exchange is used to dry the zinc-rich dust; the dedusting ash has low zinc conte...

Embodiment 2

[0038] 1) Recycling and drying iron and zinc-containing dust in iron and steel plant;

[0039] 2) Mix the dried dust with coal powder and binder in proportion, the ratio of dust to coal powder is C / O=1.5, and the binder ratio is 10%;

[0040] 3) Pellet the mixed dust on a pelletizing machine to obtain raw pellets, the diameter of which is about 25mm, plus or minus 5mm;

[0041] 4) The green pellets are fed into the shaft furnace, and are gradually heated to 1250°C by the gas rising from the bottom from top to bottom, and a self-reduction reaction occurs. 3 above;

[0042] 5) Zinc is reduced in the lower part of the blast furnace to form zinc vapor, which together with the rising gas is discharged from the shaft furnace at 700°C and enters the two-stage dust collector;

[0043] 6) The gas carrying zinc vapor enters the heat exchanger after the initial dedusting, and the heat generated by the heat exchange is used to dry the zinc-rich dust; the dedusting ash has low zinc conte...

Embodiment 3

[0047] 1) Recycling and drying iron and zinc-containing dust in iron and steel plant;

[0048] 2) Mix the dried dust, coal powder and binder in proportion, the ratio of dust to coal powder is 1.2, and the binder ratio is 4%;

[0049] 3) Pellet the mixed dust on a pelletizing machine to obtain raw pellets, the diameter of which is about 25mm, plus or minus 5mm;

[0050] 4) The raw pellets are fed into the shaft furnace, and are gradually heated to 1225°C by the gas rising from the bottom from top to bottom, and a self-reduction reaction occurs. 3 above;

[0051] 5) Zinc is reduced in the lower part of the blast furnace to form zinc vapor, which together with the rising gas is discharged from the shaft furnace at 500°C and enters the two-stage dust collector;

[0052] 6) The gas carrying zinc vapor enters the heat exchanger after the initial dedusting, and the heat generated by the heat exchange is used to dry the zinc-rich dust; the dedusting ash has low zinc content and can ...