Treatment process of dust containing iron and zinc

A treatment process and dust technology, which is applied in the field of iron and zinc dust treatment, can solve the problems of high maintenance cost, corrosion of waste heat recovery pipeline, blockage of flue gas pipeline, etc., so as to improve the effect and efficiency of zinc recovery and reduce production cost , to avoid the effect of condensation adhesion

Active Publication Date: 2022-01-11
WISDRI ENG & RES INC LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the production of rotary hearth furnaces has problems such as low thermal efficiency, high energy consumption, and large one-time investment.
At the same time, the high-temperature zinc-containing flue gas produced by the rotary hearth furnace has the characteristics of high viscosity and strong corrosion, which is easy to cause blockage of flue gas pipes and corrosion of waste heat recovery pipes, which seriously affects the long-term stability and safe operation of the rotary hearth furnace.
The maintenance cost remains high, which is one of the main reasons why rotary hearth furnaces are difficult to apply on a large scale in dust treatment in iron and steel plants
[0004] In addition, in the traditional zinc pyrometallurgy method, vertical tanks are used for zinc smelting, but they are mainly used to process zinc concentrates with an iron content below 12%. When the iron content of raw materials is high, the iron is reduced and bonded to the vertical tanks Therefore, vertical tanks are not suitable for handling zinc-containing dust in iron and steel plants. On the one hand, it is due to the low zinc content in iron and steel plant dust, and on the other hand, due to the high iron content in iron and steel plant dust. high
At the same time, in order to ensure the condensation of zinc vapor in the vertical tank smelting, excessive coal needs to be added when the vertical tank smelting zinc is pelletized, so the energy consumption is high

Method used

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  • Treatment process of dust containing iron and zinc

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] Such as figure 1 , raw materials containing iron oxide and zinc oxide and carbonaceous materials enter the raw material bin 1, and then are mixed by the mixing device 2, pressed and dried, and exchanged heat with the high-temperature flue gas of 1100 ° C in the roasting furnace 5, and heated to 900 ° C ℃ discharge, through the feeding trolley 6, the material is loaded into the reduction furnace charge tank, and the hot state charge is put into the reduction furnace 7 from the material tank, the reduction temperature is set at 1100°C, and the treatment is for 10 hours, and the reduction furnace 7 discharges the gas containing zinc vapor , the gas temperature is 1000°C, the gas composition is CO with a volume ratio of 57%, CO 2 The volume ratio is 30%, enters the lead rain condenser 8, is cooled by the 500-600 ℃ lead rain raised by the lead lifting rotor, the zinc in the gas is cooled and enters the lead pool, and the coarse zinc is separated in the lead-zinc separation p...

Embodiment 2

[0051] Raw materials containing iron oxide and zinc oxide and carbonaceous materials enter the raw material bin 1, then are mixed by the mixing device 2, pelletized and dried by discs, and exchange heat with the high-temperature flue gas at 600°C in the roasting furnace 5, and Use gas combustion to heat the formed product to 850°C and discharge it, then feed it to the reduction furnace material tank through the feeding trolley 6, and feed the hot charge into the reduction furnace 7 from the material tank, set the reduction temperature to 1050 °C, and process for 12 hours. The reduction furnace 7 discharges gas containing zinc vapor, the gas temperature is 950°C, the gas composition is 57% by volume of CO, CO 2 The volume ratio is 30%, enters the lead rain condenser 8, is cooled by the 500-600 ℃ lead rain raised by the lead lifting rotor, the zinc in the gas is cooled and enters the lead pool, and the coarse zinc is separated in the lead-zinc separation pool, cooled The final g...

Embodiment 3

[0053] Raw materials containing iron oxide and zinc oxide and carbonaceous materials enter the raw material bin 1, and then are mixed by the mixing device 2, pressed and dried, and exchanged heat with the high-temperature flue gas of 1100°C in the roasting furnace 5, and heated to 900°C It is discharged and loaded into the reduction furnace charge tank through the feeding trolley 6, and the hot state charge is fed into the reduction furnace 7 from the charge tank, and the reduction temperature is set at 1100 ° C, and the treatment is for 10 hours. The reduction furnace 7 discharges the gas containing zinc vapor, The gas temperature is 1000°C, the gas composition is 40% CO by volume, CO 2 The volume ratio is 40%, enters the lead rain condenser 8, is cooled by the 500-600 ℃ lead rain raised by the lead lifting rotor, the zinc in the gas is cooled and enters the lead pool, and the coarse zinc is separated in the lead-zinc separation pool, cooled The final gas is discharged at abo...

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Abstract

The invention relates to a treatment process for iron-zinc-containing dust, which comprises mixing a carbonaceous reducing agent with iron-zinc-containing dust to prepare pellets, sending them into a roaster to be heated to 700-900°C and then discharging them, and adding them into a reduction chamber in a hot state ; The reduction chamber is heated by indirect heating in the combustion chamber, so that the reduction reaction of the pellets occurs under the condition of isolating the air; the exhaust gas of the reduction chamber enters the lead rain condenser to recover crude zinc. The indirect heating reduction furnace is used to ensure that the zinc in the exhaust gas of the reduction chamber exists in the form of zinc vapor, and the zinc vapor in it can be recovered through the lead rain condenser to obtain crude zinc, which realizes the combination of zinc, iron oxide and alkali metal halide The purpose of separation: due to the hot state supply of pellets, the rising gas in the reduction chamber is always in contact with hot raw materials, which can effectively reduce the temperature drop of the gas and avoid the condensation and adhesion of zinc vapor in the exhaust gas of the reduction chamber.

Description

technical field [0001] The invention relates to a treatment method for dust containing iron and zinc, in particular to a treatment method for dust containing zinc and alkali metal halide produced by iron and steel enterprises. Background technique [0002] my country is a country with a large steel output, and steel production has played an important role in the development of the national economy. However, a large amount of dust and sludge are produced in steel production, which is generally about 10% of steel production. According to the current steel production, my country's steel industry produces tens of millions of tons of dust every year. In the dust (sludge) which accounts for about 30% of the total dust, in addition to Fe, it also contains a large amount of Zn, Pb, K, Na and other elements, and some dust particles are very fine. These dusts are called refractory dust or zinc-containing dust. , which contains about 72,000 tons of zinc per year. Although the traditi...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): C22B19/30C22B19/18C22B1/248C22B1/16
CPCC22B1/16C22B1/248C22B19/18C22B19/30Y02P10/20
Inventor李菊艳张国兴
OwnerWISDRI ENG & RES INC LTD