High-heat direct reduction dezincing method for zinc-containing dust carbon-bearing briquette

A dust and agglomerate technology, applied in the field of coal-based high-temperature direct reduction, can solve the problems of increasing the consumption of the reduction process

Active Publication Date: 2008-03-05
BAOSHAN IRON & STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] Above-mentioned prior art is aimed at the zinc-containing dust below 5% of zinc content, must adopt raising reduction temperature, increase reduction time, mix in more carbon content and improve the removal rate of zinc, these methods certainly are helpful for improving agglomerate The removal rate is favorable, but both increase the consumption of the reduction process

Method used

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  • High-heat direct reduction dezincing method for zinc-containing dust carbon-bearing briquette
  • High-heat direct reduction dezincing method for zinc-containing dust carbon-bearing briquette
  • High-heat direct reduction dezincing method for zinc-containing dust carbon-bearing briquette

Examples

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Effect test

Embodiment 1

[0030] The original zinc-containing dust alkalinity is 1.1, and at 1250° C., the dezincification rates obtained after reduction respectively for 10 minutes, 15 minutes, 20 minutes, and 30 minutes are shown in the comparative example in the following table 1; meanwhile, according to the present invention, the alkalinity Add slaked lime to the original zinc-containing dust of 1.1 to increase the alkalinity. The amount of slaked lime added accounts for 3.13% of the agglomerate, and the alkalinity is increased to 1.3. Then, it is mixed with coal powder to make agglomerates. 3.82% of the block, followed by reduction at 1250°C for 10 minutes, 15 minutes, 20 minutes, and 30 minutes respectively for the dezincification rates obtained in the following table 1 of the invention example. It can be clearly seen from the following table 1 that after the invention example increases the alkalinity compared with the comparative example, its dezincification rate is also significantly improved co...

Embodiment 2

[0034] The alkalinity of the zinc-containing dust is 1.1, and at 1250° C., the dezincification rates obtained after reduction respectively for 10 minutes, 15 minutes, 20 minutes, and 30 minutes are shown in the comparative example in the following table 2; meanwhile, according to the present invention, the alkalinity Lime powder is added to the original zinc-containing dust of 1.1 to increase the alkalinity. The amount of lime powder added accounts for 5.03% of the agglomerate, and the alkalinity is increased to 1.8. Coal powder is then mixed in for agglomeration, and the amount of coking coal powder added accounts for 3.70% of the agglomerate. Then, the dezincification rates obtained after reduction at 1250° C. for 10 minutes, 15 minutes, 20 minutes, and 30 minutes are also shown in the invention examples in Table 2 below. It can be clearly seen from the following table 2 that after the inventive example increases the alkalinity compared with the comparative example, its dezi...

Embodiment 3

[0038] The alkalinity of the zinc-containing dust is 1.1, and at 1250° C., the dezincification rates obtained after reduction for 10 minutes, 15 minutes, 20 minutes, and 30 minutes are shown in the comparative example in the following table 3; meanwhile, according to the present invention, the alkalinity Adding limestone and dolomite mixed mud cake to the original zinc dust of 1.1 accounted for 14.2% of the agglomerate, increasing the alkalinity to 2.0. Then add petroleum coke powder to make agglomerates, and the amount of added petroleum coke powder accounts for 2.31% of the agglomerate. Then, the dezincification rates obtained after reduction at 1250° C. for 10 minutes, 15 minutes, 20 minutes, and 30 minutes are also shown in the invention examples in Table 3 below. It can be clearly seen from the following table 3 that after the alkalinity of the inventive example is increased compared with the comparative example, the dezincification rate is also significantly improved com...

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Abstract

The direct high temperature reduction process to eliminate zinc from zinc containing dust pellet includes the following steps: 1. analysis to determine the CaO, MgO, SiO2 and Al2O3 contents in zinc containing dust with zinc content lower than 5 wt% and calculate ternary (CaO+MgO)/(SiO2+Al2O3) alkalinity value; 2. adding one or several of slaked lime, lime limestone, dolomite powder and alkaline steel slag powder to zinc dust to control the alkalinity value in 1.3-2.6; 3. adding coal powder, coke powder, petroleum powder and/or graphite powder, mixing and rolling or pressing into pellet; and 4. heating the pellet at 1100-1350 deg.c for over 10 min to reduce zinc while reducing ferric iron into metal iron. The process has high zinc eliminating rate and no increased loss.

Description

technical field [0001] The invention relates to the technical field of coal-based high-temperature direct reduction, in particular to a method for high-temperature direct reduction and dezincification of zinc-containing dust mixed with carbon material blocks. Background technique [0002] Coal-based high-temperature direct reduction technology is one of the important methods to deal with zinc-containing dust or dust sludge generated in the process of steelmaking and ironmaking in iron and steel plants. This method is to mix zinc-containing dust with carbon to form agglomerates, and then directly reduce it at a high temperature above 800°C to make an iron-containing charge with a certain metallization rate and collect the metals such as zinc in the agglomerate to volatilize, and separate the former ( Iron-containing charge) is used for ironmaking or steelmaking in steel plants, and the latter (secondary dust rich in zinc metal and its oxides collected by volatilization) is us...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B19/30C22B5/10
CPCY02P10/20
Inventor 王东彦
Owner BAOSHAN IRON & STEEL CO LTD
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