Iron-making method adopting carbothermal pre-reduction, gas-based deep reduction and synchronous cooling

A gas-based, carbon-thermal technology, applied in waste gas treatment, climate sustainability, sustainable manufacturing/processing, etc., can solve the complex gas source isolation control system, low carbon-thermal reduction degree of pellets, and slow gas-based reduction rate and other problems, to achieve the effect of promoting gas-based reduction rate, good internal porosity, and fast carbon-thermal pre-reduction rate

Pending Publication Date: 2020-06-19
CENT IRON & STEEL RES INST +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In view of the above analysis, the embodiment of the present invention aims to provide an ironmaking method of carbothermal pre-reduction, gas-based deep reduction and synchronous cooling to solve the problem of low carbon-thermal reducti

Method used

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  • Iron-making method adopting carbothermal pre-reduction, gas-based deep reduction and synchronous cooling
  • Iron-making method adopting carbothermal pre-reduction, gas-based deep reduction and synchronous cooling
  • Iron-making method adopting carbothermal pre-reduction, gas-based deep reduction and synchronous cooling

Examples

Experimental program
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Example Embodiment

[0043] Example 1

[0044] Guohai sand vanadium-titanium magnetite, TFe content is 56%, chemical composition is shown in Table 1, the particle size of the mineral powder is less than 80 mesh.

[0045] Table 1 Chemical composition of sea sand vanadium-titanium magnetite (%)

[0046] TFe FeOFe 2 O 3

[0047] After the vanadium-titanium magnetite and the binder are uniformly mixed, carbon-containing pellets are prepared by a roller ball press. Place 10kg pellets in a vertical reduction furnace for heating, and use H 2 It is reducing gas, reducing 4~10h at 900℃, and passing N after reduction 2 Cool to 4h. The reduced pellets were crushed and ground to prepare powder samples, and the metallization rate of the samples was determined by chemical titration analysis. H 2 And N 2 The flow rate is 50L / min, H 2 And N 2 The ratio of gas volume to pellet mass is 1.2~3Nm, respectively 3 / kg、1.2Nm 3 / kg.

[0048] The experimental results show that when the pellet reduction time is 4h, 6h, 8h, an...

Example Embodiment

[0049] Example 2

[0050] Use the same raw material of vanadium-titanium magnetite as above. After mixing vanadium-titanium magnetite, binder, and coal powder uniformly, carbon-containing pellets are prepared by a roller ball press, and the pellets C / O=1.2. The chemical composition of pulverized coal is shown in Table 2.

[0051] Table 2 Chemical composition of anthracite coal powder for reduction,%

[0052] composition(%) Fixed carbon Volatile AshS Moisture anthracite 74.535.1617.860.442.45

[0053] Place 10kg of carbon-containing pellets in an electric heating small rotary hearth furnace for heating, and reduce at 1250°C for 15-30 minutes to simulate the carbothermal reduction process of carbon-containing pellets. The reduced pellets were crushed and ground to prepare powder samples, and the metallization rate of the samples was determined by chemical titration analysis.

[0054] The experimental results show that when the pellet reduction time is 15min, 20min, 25min, and 30m...

Example Embodiment

[0055] Example 3

[0056] In this example, the carbon-containing scout prepared in Example 1 was used for pre-reduction, deep reduction, and simultaneous cooling.

[0057] Place 10kg of carbon-containing pellets in a small rotary hearth furnace for heating, pre-reduction at 1250°C for 15min and 20min, stop heating after reduction, and discharge the hot metalized pellets into vertical reduction through the discharger after reduction Cooler, access H 2 Reduction cooling 4h, H 2 Flow rate is 50L / min, H 2 The ratio of gas volume to pellet mass is 1.2Nm 3 / kg.

[0058] The high-temperature gas after reduction and heat exchange is heat exchanged in the waste heat boiler to produce supersaturated steam for power generation. The temperature of the gas after heat exchange in the waste heat boiler is 200 ℃, and then cooled to below 50 ℃ by a water cooler, and the cooled gas passes through a dehumidifier After dehumidification, return to the vertical reduction cooler for recycling, and the ins...

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Abstract

The invention relates to an iron-making method adopting carbothermal pre-reduction, gas-based deep reduction and synchronous cooling, and belongs to the field of non-blast furnace ironmaking. The problems of low carbon thermal reduction degree, low gas-based reduction rate and long cooling time of existing pellets and complex gas source isolation control system due to different gas sources of a reduction section and a cooling section during gas-based reduction are solved. The iron-making method adopting carbothermal pre-reduction, gas-based deep reduction and synchronous cooling comprises thefollowing steps that 1, the carbon-containing pellets are subjected to pre-reducing by using a rotary hearth furnace to obtain porous pre-reduced metalized pellets; 2, the porous pre-reduced metalizedpellets are discharged into a vertical reduction cooling reactor in a hot state, and subjected to countercurrent reduction and heat exchange with cold-state reducing gas; and 3, the high-temperaturegas subjected to reduction and heat exchange is subjected to heat exchange through a waste heat boiler, physical heat is utilized, and after the cooled gas is dehumidified and subjected to impurity removal, unreacted reducing gas returns to the vertical reduction cooling reactor to be recycled. According to the method, the high reduction degree effect that the pellet metallization rate is larger than 90% within 3 h-5 h is achieved.

Description

technical field [0001] The invention relates to the field of non-blast furnace ironmaking methods, in particular to an ironmaking method comprising carbothermal pre-reduction, gas-based deep reduction and synchronous cooling. Background technique [0002] Blast furnace ironmaking is the main method of ironmaking in my country, accounting for the absolute share of my country's iron production, but there are two characteristics of blast furnace smelting, one is to ensure the air permeability of the blast furnace, there must be a coke layer, the price of coke is high, and the coking process is seriously polluted by the environment The second is that the strength of the raw materials is high, and clinker is mainly used to enter the furnace, including sintered ore or oxidized pellets, which increases the cost of smelting and produces a large amount of tail gas, which increases the cost of treatment. Non-blast furnace ironmaking does not use sinter or oxidized pellets as raw materi...

Claims

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Application Information

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IPC IPC(8): C21B13/08C21B13/02
CPCC21B13/02C21B13/08C21B13/029C21B2100/66
Inventor 张俊周和敏齐渊洪严定鎏
Owner CENT IRON & STEEL RES INST
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