Iron making process in blast furnace and additives therefor

A blast furnace ironmaking and additive technology, which is applied in blast furnaces, blast furnace details, furnaces, etc., can solve the problems of unfavorable blast furnace intensified smelting, large addition amount, and increased production cost.

Inactive Publication Date: 2005-09-07
NORTHEASTERN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Adding magnesium-containing compounds to sintered ore can also help reduce the low-temperature pulverization rate of sintered ore at first glance; however, due to the large amount of MgO added, it brings the following new problems: (1) Reduce the sintering rate. (2) Make the cold strength of sintered ore worse; (3) Make the temperature range of the reflow zone in the blast furnace rise by 60-100°C, so that the overall pressure difference of the blast furnace charge column increases, This is not conducive to the intensified smelting of the blast furnace
Although the above process is widely used, the inventors believe that it is not a scientific method to add MgO in the blast furnace ironmaking process

Method used

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  • Iron making process in blast furnace and additives therefor

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Effect test

Embodiment 1

[0023] In a steel company 1800M 3 On blast furnace 1, control the content of MgO in the sinter to 0.9wt%, with 4.0wt% CaCl 2 Additives are sprayed on sintered ore at a rate of 4.5 kg / ton as raw material for blast furnace ironmaking. Utilize existing pulverizing injection system, the MgO-containing additive of following formula:

[0024] Composition Weight percent (wt%)

[0025] MgO 82.3

[0026] CaO 12.5

[0027] SiO 2 1.4

[0028] Burnout 3.8

[0029] It is fed into the coal mill together with the raw coal for pulverization, and the pulverized coal is sprayed into the blast furnace from the tuyere 4. The injection equivalent of MgO additive is 20 kg / ton of iron. The adoption of this process effectively increases the output of sintered ore, reduces the low-temperature reduction pulverization rate of sintered ore; improves the air permeability of the block zone 2 of the blast furnace, and reduces the pressure difference of the material column by 20kP...

Embodiment 2

[0031] at 1250M 3 Implementation of the process of the present invention on the blast furnace 1. Since the content of magnesium oxide in its sintered ore is 0.8wt%, so 4.0wt% CaCl 2 The aqueous solution is evenly sprayed on the surface of the sintered ore at 200° C. at a usage rate of 5 kg / ton according to the weight of the sintered ore, and then fed into the blast furnace 1 . The MgO-containing additive of the following formula is added again:

[0032] Composition Weight percent (wt%)

[0033] MgO 80

[0034] CaO 14

[0035] SiO 2 2

[0036] burnout 4

[0037] Together with the raw coal, put it into a coal mill to grind it into powder, and spray it into the blast furnace from the tuyere 4. The injection equivalent of the additive is 25 kg / ton of iron. It increases the combustion rate of pulverized coal before the tuyere by about 5%, and at the same time significantly improves the smelting intensity of the blast furnace and the quality of pig iron...

Embodiment 3

[0039] at 750M 3 Implementation of this process on the blast furnace 1. With 4.0wt% CaCl 2 The aqueous solution is evenly sprayed on the surface of the sintered ore (containing MgO 0.8wt%) below 200° C. according to the proportion of sintered ore weight 4.2 kg / ton, and then fed into the blast furnace. The MgO-containing additive of the following formula is added again:

[0040] Composition Weight percent (wt%)

[0041] MgCO 3 80

[0042] CaO 14

[0043] SiO 2 2

[0044] burnout 4

[0045] Add the pulverized coal together with the raw coal, and blow the pulverized coal into the blast furnace from the tuyere 4. The injection equivalent of MgO additive is 20 kg / t iron. The production efficiency of the blast furnace is very good.

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Abstract

The invention discloses a new iron-smelting process of adding magnesium oxide scientifically in blast furnace, and it is characterized in that the magnesium oxide is made to additive which is mixed with raw coal and made to coal powder containing magnesium oxide and is injected into blast furnace 1 from tuyere 4. The invention also provides the magnesium oxide addictive which is used for iron-smelting in the new process. The formulation of the addictive calculated by weight is: MgO 80-83; CaO 12-14; SiO21-2; fire waste 4-6. The main component magnesium oxide can be replaced by magnesium compounds. The invention is modifying the preexisting process of adding magnesium oxide to sintered ore to the new process of adding magnesium oxide into the furnace through tuyere 4 by using coal powder. By applying the process in this invention the air permeability in lump area 2 can be improved; the thickness of reflowing area 3 can be decreased; the combustion efficiency of coal powder can be increased and the flowability and desulfurizing ability can be improved, which is good for the increase of the smelting strength of blast furnace and the yield and quantity of foundry iron.

Description

technical field [0001] The invention belongs to the technical field of blast furnace ironmaking. Specifically, the present invention provides a new process of scientifically adding magnesium oxide in the blast furnace ironmaking process and an additive for ironmaking in the new process. Background technique [0002] In the blast furnace ironmaking production, it is necessary to ensure that the blast furnace slag contains a certain amount of magnesium oxide (MgO). MgO can improve the desulfurization ability of slag, improve the fluidity of slag, reduce the pressure loss of the reflow zone and control the thickness of the reflow zone of the blast furnace, which is conducive to improving the smelting strength of the blast furnace and increasing the output. Since the raw materials of the blast furnace - sintered iron ore itself, coal powder and co-solvent usually do not contain MgO, the existing technology is to add dolomite (CaCO 3 · MgCO 3 ) or magnesite (MgCO 3 ). Adding...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21B5/02
Inventor 沈峰满吴钢生姜鑫李小钢魏国沈岩柏
Owner NORTHEASTERN UNIV
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