WO2020258806A1

WO2020258806A1 - Joint coal gasification and molten iron reduction device and method having sufficient preheating and gas phase prereduction

Info

Publication number: WO2020258806A1
Application number: PCT/CN2019/129538
Authority: WO
Inventors: 马春元; 赵媛; 王涛; 周滨选; 周振峰; 陈娟
Original assignee: 山东大学
Priority date: 2019-06-27
Filing date: 2019-12-28
Publication date: 2020-12-30
Also published as: CN110218831A

Abstract

A joint coal gasification and molten iron reduction device and method having sufficient preheating and gas phase prereduction, belonging to the technical field of steel smelting. The device comprises an iron ore powder preparation system, a coal powder preparation system, a high-temperature gasification melting section (16), a medium-temperature carbonization section (20), a coke powder separation device (21), and a low-temperature multistage gas phase reduction preheating section. The high-temperature gasification melting section (16) is connected with the medium-temperature carbonization section (20) by a U-shaped structure; a shared ash hopper (17) is arranged at the lower part of the U-shaped structure; a slag pool (18) and a slag conveyor (19) are arranged below the ash hopper (17). The high-temperature gasification melting section (16) adopts a vertical downer design which realizes liquid-state slag removal, a coke powder feeding opening is formed at the upper end, and semi-reduced iron ore powder is subjected to smelting reduction. The medium-temperature carbonization section (20) adopts a vertical riser design, and coal powder is carbonized into coke. The upper end of the medium-temperature carbonization section (20) is connected with the coke powder separation device (21); the coke powder separation device (21) is connected with the low-temperature multistage gas phase reduction preheating section, and sufficient preheating of the iron ore powder promotes prereduction. Finally, the process of gas phase reduction and smelting reduction of the iron ore powder is finished, realizing a short iron-making process with promotion of prereduction by sufficient preheating.

Description

Coal gasification cooperative molten iron reduction device and method with full preheating and gas phase prereduction

Technical field

The invention belongs to the technical field of steel smelting, and specifically relates to a coal gasification synergistic molten iron reduction process with sufficient preheating and gas phase prereduction.

Background technique

Disclosure of the background information is only intended to increase the understanding of the overall background of the present invention, and is not necessarily regarded as an acknowledgement or in any form suggesting that the information constitutes the prior art known to those of ordinary skill in the art.

China's steel production is mainly based on long-process smelting of coking, sintering, pelletizing, blast furnace, and converter. Blast furnace ironmaking is an important part of modern steel production. It is a method of continuously producing liquid pig iron in a blast furnace using coke, iron-containing ore and flux. In recent years, China's blast furnace ironmaking technology has developed rapidly, and is constantly moving towards automation, large-scale and high-efficiency. However, the blast furnace ironmaking industry is also facing problems such as saturation, low economic returns, and insufficient competitiveness in the world market. As the country proposes to implement structural reforms on the supply side of the iron and steel industry and environmental restrictions on production, the energy consumption of ironmaking has increased, prompting structural reforms in the existing blast furnace ironmaking process. In order to get rid of the limitation of the shortage of coking coal resources on the development of ironmaking and adapt to the increasingly stringent environmental protection requirements, short-flow ironmaking technology has gradually become a research hotspot in the steel industry, but the existing short-flow ironmaking technology has low waste heat recovery and high raw material costs. problem.

Patent CN201811303409.5 is a short-process smelting reduction ironmaking system and method. The iron ore powder direct reduction and powder coke preparation device is a U-shaped structure at the bottom, with low temperature reduction section and high temperature reduction section on both sides, and smelting reduction section at the bottom. Section, the molten iron is obtained from the bottom of the smelting reduction section, the pulverized coal preparation device and the iron ore powder preparation device are respectively connected to the lower part and the bottom of the low temperature reduction section, the low temperature reduction section is connected to the gas-solid separation device, and the gas-solid separation device is respectively connected to the high temperature The top combustion device and the middle part of the reduction section are connected. However, because the device adopts a two-stage type, with only a low-temperature reduction section and a high-temperature reduction section, the pre-reduction of ore fines and pulverized coal coke production are both performed in the low-temperature reduction section, and the coke iron is separated later, and the device structure is complicated.

Summary of the invention

In order to overcome the above-mentioned problems, the present invention provides a coal gasification and molten iron reduction process with sufficient preheating and gas phase prereduction. The pulverized coal is carbonized to make coke, and the resulting coke powder is burned and gasified under pure oxygen to form a reducing atmosphere. The added semi-reduced iron ore powder is smelted and reduced in the reducing atmosphere to achieve the separation of slag and iron, and finally the iron ore is reduced to Iron; At the same time, the coal gas produced in the coking process is preheated by multi-stage gas phase reduction, and the upper-level iron ore powder is carried into the iron ore powder separator and pre-reduction reactor, which plays a role in preheating and pre-reducing the iron ore powder. Heat promotes the pre-reduction process and makes full use of the gas calorific value.

In order to achieve the above technical objectives, the technical solutions adopted by the present invention are as follows:

A coal gasification cooperative molten iron reduction device with full preheating and gas phase prereduction, including: iron ore powder preparation system, coal powder preparation system, high temperature gasification melting furnace, medium temperature carbonization furnace, ash hopper, and first-level iron ore powder separation The high temperature gasification melting furnace and the medium temperature carbonization furnace are connected by a U-shaped structure, the lower part is a public ash hopper, and the top of the high temperature gasification melting furnace is provided with a burner. The upper part of the carbonization furnace is connected to the coke powder separator, and the top of the coke powder separator is connected to the bottom outlet of the secondary iron ore powder separator and the inlet on the side wall of the pre-reduction reactor. The bottom outlet of the pre-reduction reactor is connected to the burner, the bottom outlet of the pre-reduction reactor is connected to the high-temperature gasification melting furnace, and the top outlet of the pre-reduction reactor is respectively connected to the inlet and the first-stage side wall of the secondary iron ore separator The outlet at the bottom of the iron ore powder separator is connected, the outlet at the top of the second-level iron ore separator is connected to the inlet of the side wall of the first-level iron ore separator, and the first-level iron ore separator is connected to the iron ore separator. The ore powder preparation system is connected, the medium temperature carbonization furnace is connected to the coal powder preparation system, and the ash hopper is connected to the slag pool.

The present invention proposes a coal gasification synergistic iron reduction process. The produced gas is used for iron ore powder preheating and pre-reduction. A two-stage iron ore powder separator and a pre-reduction reactor are used to promote the preheating of iron ore powder. Pre-reduction, and then smelting reduction of the pre-reduced iron ore powder, forms a set of short-flow ironmaking processes with low energy consumption, which is of great significance to the development of short-flow ironmaking processes.

In some embodiments, the iron ore powder preparation system consists of an iron ore bin, a first crusher, a crushing bin, a first mill, a bag dust collector, an iron ore powder bin, and an iron ore powder feeder in sequence. Connected together. The above-mentioned device can grind iron ore to the required particle size and put it into the system furnace, improve the utilization rate of iron ore powder and reduce energy consumption.

In some embodiments, the pulverized coal preparation system is composed of a raw coal silo, a second crusher, a crushed coal silo, a second pulverizer, a coarse coal separator, a coarse coal silo, and a pulverized coal feeder. . The above-mentioned device can realize the classification and utilization of coarse and fine coal powder, and at the same time realize the balance and matching of consumption between coarse and fine powder.

In some embodiments, a slag conveyor is provided in the slag tank. The above device can remove iron slag quickly and efficiently, has a high slag removal rate, and significantly reduces iron loss.

In some embodiments, the high-temperature gasification melting furnace has a vertical down-bed structure. The above-mentioned structure can fully react the reducing gas with the preheated semi-reduced iron ore powder, thereby improving the yield and the quality of molten iron.

Compared with the existing short-process smelting reduction ironmaking system, this application has a three-stage type, namely a high-temperature gasification melting section, a medium-temperature carbonization section, and a low-temperature multi-stage gas-phase reduction and preheating section, ore powder pre-reduction preheating and coal The powder coke is produced in two reaction sections separately, which reduces the coke-iron separation process. In some embodiments, the high-temperature gasification melting furnace is a liquid slag discharge, and the upper end is a coke powder feeding port to facilitate the reduction of iron ore powder.

In some embodiments, the medium-temperature carbonization furnace has a vertical up-bed structure, so that pulverized coal is injected from the side of the lower end of the medium-temperature carbonization section, and coke is produced through a carbonization activation process.

In some embodiments, the side wall of the intermediate temperature carbonization furnace is provided with a pulverized coal inlet, which facilitates the use of different types of pulverized coal to make coke. The resulting coke has similar physical and chemical properties and can be used for iron reduction in the high-temperature gasification melting section.

The present invention also provides a coal gasification cooperative molten iron reduction process with sufficient preheating and gas phase prereduction, including:

Coal powder is pyrolyzed and gasified to produce coal gas and coke powder;

The coal gas undergoes a pre-reduction reaction with the two-stage preheated iron ore powder to form semi-reduced iron ore powder,

The coke powder is combusted to generate reducing gases such as H ₂ and CO, and reacts with semi-reduced iron ore powder at high temperature to generate molten iron. In the low-temperature multi-stage gas-phase reduction preheating section of the present application, the iron ore powder is preheated in two stages and then pre-reduced. Full pre-heating promotes the pre-reduction.

In some embodiments, the heat source for the two-stage preheating of iron ore powder is the coal gas. The coal gas generated by gasification of pulverized coal is used to fully preheat the iron ore powder in the two-stage iron ore powder separator, which promotes the pre-reduction process of the iron ore powder. The quality of the molten iron is better, and the complexity of the ironmaking process is reduced. The process is shorter and the production energy consumption is lower.

The beneficial effects of the present invention are:

(1) The present invention proposes a coal gasification cooperative molten iron reduction process with sufficient preheating and gas phase prereduction. According to the conditions required for the reduction of iron ore powder to iron, a low temperature multi-stage gas phase reduction preheating section and high temperature gasification melting are designed. Section, respectively control the temperature range in the two sections of the reactor, so that the gas phase preheating and pre-reduction process of iron ore powder is completed in the low temperature section, and the semi-reduced iron ore powder smelting reduction process is completed in the high temperature section, using the coal gas generated by gasification of pulverized coal The iron ore powder is fully preheated in the two-stage iron ore powder separator, which promotes the pre-reduction process of the iron ore powder. The quality of the molten iron is better, the complexity of the ironmaking process is reduced, the system process is shorter, and the production energy consumption is higher. low. At the same time, different types of pulverized coal can be used to make coke in the medium temperature section, and the obtained coke has similar physical and chemical properties, and can be used to reduce iron in the high temperature gasification melting section. It has strong applicability to coal and has broad application prospects.

(2) The device of the present application has simple structure, low cost, universal applicability, and is easy to scale production.

Description of the drawings

The drawings of the specification forming a part of the application are used to provide a further understanding of the application, and the exemplary embodiments and descriptions of the application are used to explain the application, and do not constitute an improper limitation of the application.

Figure 1 is a coal gasification synergistic molten iron reduction process and device with full preheating and gas phase prereduction in Example 1;

Among them: 1. Iron ore warehouse; 2. First crusher; 3. Crushing ore warehouse; 4. First mill; 5. Bag dust collector; 6. Iron ore powder warehouse; 7. Iron ore powder feeding Machine; 8. Raw coal bin; 9. Second crusher; 10. Coal crushing bin; 11. Second mill; 12. Coarse coal separator; 13. Coarse coal bin; 14. Coal feeder; 15. Burner; 16. High temperature gasification and melting section; 17. Ash hopper; 18. Slag tank; 19. Slag conveyor; 20. Intermediate temperature carbonization section; 21. Coke powder separator; 22. Primary iron ore powder separation Device; 23, secondary iron ore powder separator; 24, pre-reduction reactor; 25, coke powder feeder.

Detailed ways

It should be pointed out that the following detailed descriptions are all illustrative and are intended to provide further explanations for the application. Unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs.

It should be noted that the terms used here are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprising" and/or "including" are used in this specification, they indicate There are features, steps, operations, devices, components, and/or combinations thereof.

As introduced in the background art, the existing short-flow ironmaking process has the problems of low waste heat recovery and high raw material cost. Therefore, the present invention proposes a coal gasification cooperative molten iron reduction process device with sufficient preheating and gas phase prereduction, including an iron ore powder preparation system, a coal powder preparation system, a high temperature gasification melting section, an intermediate temperature carbonization section, and a coke powder separation device , Low temperature multi-stage gas phase reduction preheating section; high temperature gasification melting section and medium temperature carbonization section are connected by a U-shaped structure, the lower part is a public ash hopper, under the ash hopper is a slag tank and a slag conveyor; the high temperature gasification melting section is vertical Downward bed design, liquid slag discharge, the upper end is a coke powder feeding port; the medium temperature carbonization section is a vertical upward bed design, coal powder is injected from the side of the lower end of the medium temperature carbonization section, and coke is produced through the carbonization activation process; the upper end of the medium temperature carbonization section The coke powder separation device is connected to separate coke powder and coal gas; the upper end of the coke powder separation device is connected to the low-temperature multi-stage gas phase reduction preheating section.

Preferably, the iron ore powder preparation system includes an iron ore bin, a first crusher, a crushing bin, a first mill, a bag filter, an iron ore powder bin, and an iron ore powder feeder.

Preferably, the pulverized coal preparation system includes a raw coal silo, a second crusher, a crushed coal silo, a second pulverizer, a coarse coal separator, a coarse pulverized coal silo, and a pulverized coal feeder.

Further preferably, the coarse coal separator is connected to the bag filter.

The iron ore powder preparation system can grind the iron ore to the required particle size, and put it into the low-temperature multi-stage gas phase reduction preheating section to realize the preheating and pre-reduction process; the coal powder preparation system can grind the raw coal to the desired particle size. The particle size is required, and the coarse and fine-level utilization of coal powder is realized.

Preferably, the high-temperature gasification and melting section from top to bottom is a coke powder combustion device and a semi-reduced iron ore powder smelting reduction section. The upper end of the high-temperature gasification and melting section is connected to the coke powder feeding port, and the molten iron and molten slag are downwardly discharge.

Preferably, the upper end of the intermediate temperature carbonization section is connected with a coke powder separator, and the lower end is connected with a coal powder feed port.

Further preferably, the high-temperature gasification melting section and the medium-temperature carbonization section are connected in a U-shaped structure, and a common ash hopper is provided with a slag tank and a slag conveyor under the ash hopper.

Preferably, the upper end of the coke powder separator is connected to the low-temperature multi-stage gas phase reduction preheating section, and the lower end is connected to the burner on the top of the high-temperature gasification melting section.

More preferably, the temperature of the coal gas discharged from the upper end of the coke powder separator is the highest.

Preferably, the low-temperature multi-stage gas-phase reduction preheating section is composed of a two-stage iron ore powder separator and a pre-reduction reactor. The upper end of the two-stage iron ore powder separator discharges coal gas of different temperatures, and the lower end separates the gas after being preheated by the gas of different temperatures. The higher temperature coal gas is discharged from the upper end of the pre-reduction reactor, and the lower end separates the iron ore powder pre-reduced by the higher temperature gas.

More preferably, the temperature of the gas discharged from the first-level iron ore powder separator is the lowest, the temperature of the gas discharged from the second-level iron ore separator is lower, and the temperature of the gas discharged from the pre-reduction reactor is higher; The temperature of the ore powder is the lowest, the temperature of the iron ore powder separated by the secondary iron ore powder separator is medium, and the temperature of the iron ore powder separated by the pre-reduction reactor is the highest.

More preferably, the two-stage iron ore powder separator mainly plays a role of preheating, and the pre-reduction reactor mainly plays a role of pre-reduction, and sufficient preheating of the iron ore powder promotes subsequent pre-reduction. The terminal temperature is low, mainly preheating, and pre-reduction as the temperature increases.

A coal gasification and molten iron reduction process with full preheating and gas phase prereduction, the specific steps are:

1) Powder preparation

Iron ore and raw coal pass through the iron ore powder preparation system and the coal powder preparation system respectively, and the raw materials are crushed, ground, and separated.

Do not enter the iron ore powder warehouse and coarse coal powder warehouse for standby;

2) Middle temperature section: pulverized coal coking

The pulverized coal produced by the pulverized coal preparation system is sent to the lower end of the medium-temperature carbonization section. The pulverized coal is pyrolyzed and gasified under the action of the temperature and atmosphere of the high-temperature section to produce gas and powder coke. Under the action of the updraft bed, the gas and powder coke enter the upper end Powder coke separator;

3) Low temperature section: low temperature multi-stage gas phase reduction preheating

The coal gas with the highest temperature is discharged from the upper end of the powder coke separator, and the secondary preheated iron ore powder separated from the lower end of the secondary iron ore powder separator enters the pre-reduction reactor; the temperature in the pre-reduction reactor is higher, and the pre-reduction of iron ore powder mainly occurs Reduction reaction, the higher temperature gas is discharged from the upper end, and the primary preheated iron ore powder separated at the lower end of the first-level iron ore powder separator enters the second-level iron ore powder separator; the second-level iron ore powder separator has a lower temperature, which mainly affects The iron ore powder plays a role of preheating, and the lower temperature gas is discharged from the upper end, and the iron ore powder input from the iron ore powder bin enters the first-level iron ore powder separator; the first-level iron ore powder separator has the lowest temperature, mainly for iron ore powder It plays a role of preheating, and the upper end discharges the lowest temperature coal gas; the two-stage iron ore separator mainly plays a role of preheating, and the role of pre-reduction as the temperature rises is the main role. The pre-reduction reactor mainly plays the role of pre-reduction, and full preheating promotes Pre-reduction.

4) High temperature section: pure oxygen combustion and gasification of coke, iron smelting reduction

The coke powder separated at the lower end of the coke powder separator is sent to the burner at the top of the high temperature section, where it undergoes combustion and gasification reaction under pure oxygen conditions.

Generates reducing gases such as H ₂ and CO, and generates a large amount of heat; the semi-reduced iron ore powder separated at the lower end of the pre-reduction reactor is transported

Into the upper end of the high-temperature section, under the reducing atmosphere and high-temperature conditions, the semi-reduced iron ore powder becomes a molten state and gasifies at high temperature.

Smelting reduction reaction occurs in the melting section, reducing to molten iron, and finally achieving slag and iron separation.

The structure and process of this application will be further explained below in conjunction with the drawings:

Example 1:

The structure of a coal gasification cooperative molten iron reduction process and device with full preheating and gas phase prereduction includes an iron ore powder preparation system, consisting of an iron ore bin 1, a first crusher 2, a crushing bin 3, and a first grinding powder Machine 4, bag filter 5, iron ore powder bin 6, iron ore powder feeder 7, iron ore powder feeder 7 is connected to the feed inlet of the first-level iron ore powder separator 22; the coal powder preparation system is composed of raw coal Bin 8, the second crusher 9, the coal crushing bin 10, the second pulverizer 11, the coarse powder separator 12, the coarse pulverized coal bin 13, and the pulverized coal feeder 14; the intermediate temperature carbonization section 20 is an upward flow bed, The upper end is connected to the coke powder separator 21, the lower end is connected to the pulverized coal feeder 14, and the bottom is an ash hopper 17; the high temperature section is a descending bed, which includes burner 15, high temperature gasification melting section 16, and ash hopper 17, from top to bottom. The upper end is connected to the semi-reduced iron ore powder feeder 25; the middle temperature section and the high temperature section are arranged in U-shaped structure, sharing a ash hopper 17, and the lower part of the ash hopper 17 is provided with a slag pool 18 and a slag conveyor 19; the upper end of the coke separator 21 is connected to low temperature The pre-reduction reactor 24 of the multi-stage gas-phase reduction preheating section is connected to the burner 15 at the top of the high-temperature section by a feeder; the low-temperature multi-stage gas-phase reduction preheating section is composed of a primary iron ore powder separator 22 and a secondary iron Ore powder separator 23, pre-reduction reactor 24, and semi-reduced iron ore powder feeder 25; the inlet of the primary iron ore powder separator 22 is connected to the upper outlet of the secondary iron ore powder separator 23 and the iron ore powder feeder 7. The upper outlet is the gas outlet, the lower outlet is the primary preheated iron ore powder outlet; the inlet of the secondary iron ore separator 23 is connected to the upper outlet of the pre-reduction reactor 24 and the lower outlet of the primary iron ore separator 22, and the upper outlet It is the gas outlet, and the lower outlet is the secondary preheated iron ore powder outlet; the inlet of the pre-reduction reactor 24 is connected to the upper outlet of the coke powder separator 21 and the lower outlet of the secondary iron ore separator 23. The upper outlet is the gas outlet, and the lower outlet is It is the semi-reduced iron ore powder outlet, and the lower end outlet is connected to the semi-reduced iron ore powder feeder 25, and leads to the upper end of the high temperature section.

1) Powder preparation

As shown in Figure 1, the iron ore powder preparation system is arranged vertically, the iron ore is ground into iron ore powder with a diameter of 100-500μm after the first crusher and the first mill, and the iron ore powder is pumped into the bag for dust removal After the device is stored in the iron ore powder bin; the coal powder preparation system is arranged vertically, the raw coal is ground into a 100-500μm diameter coal after the second crusher and the second mill, and the coal powder is pumped into the coarse coal to separate After the device, it is stored in the pulverized coal bin for later use.

2) Middle temperature section: pulverized coal coking

The pulverized coal produced by the pulverized coal preparation system is sent from the pulverized coal feeder to the lower end of the medium-temperature carbonization section. The pulverized coal is pyrolyzed and gasified under the action of the temperature and atmosphere of the high-temperature section to produce coal gas and coke. Under the action of the updraft bed, Gas and powder coke enter the coke powder separator at the upper end;

The coal gas with the highest temperature is discharged from the upper outlet of the coke powder separator, the gas temperature is about 800-1000℃, and the secondary preheated iron ore powder separated at the lower end of the secondary iron ore separator is carried into the pre-reduction reactor to preheat the iron twice. The temperature of the ore powder is about 400-700℃; the higher temperature coal gas is discharged from the upper outlet of the pre-reduction reactor, and the gas temperature is about 600-800℃. The primary preheated iron ore powder separated from the lower outlet of the primary iron ore powder separator enters the second Grade iron ore separator, the temperature of preheating iron ore powder is about 200-400℃; the upper end of the second-level iron ore separator discharges lower temperature coal gas, and the gas temperature is about 400-600℃. The iron ore powder enters the first-level iron ore powder separator, and the temperature of the iron ore powder is about -20～40℃ (the temperature varies according to environmental changes); the lowest temperature gas is discharged from the upper outlet of the first-level iron ore powder separator, and the gas temperature is 200 ～400℃; The two-stage iron ore powder separator mainly plays a role of preheating, and the role of pre-reduction as the temperature increases. The pre-reduction reactor mainly plays a role of pre-reduction, and full preheating promotes pre-reduction.

The coke powder separated at the lower outlet of the coke powder separator is sent to the burner at the top of the high-temperature section. The temperature of the separated coke powder is about 750～950℃, and the combustion and gasification reaction occurs under pure oxygen conditions to generate reducing gases such as H ₂ and CO. , Produces a lot of heat, the temperature reaches 1300～1600℃; the temperature of the semi-reduced iron ore powder separated at the lower end of the pre-reduction reactor is about 600～900℃, and is fed into the upper end of the high temperature section through the semi-reduced iron ore powder feeder, in a reducing atmosphere Under the conditions of high temperature and high temperature, the semi-reduced iron ore powder turns into a molten state, a smelting reduction reaction occurs in the high-temperature gasification melting section and flows downwards, and is reduced to molten iron, and finally the slag and iron are separated and fall into the slag pool.

Example 2:

A coal gasification cooperative molten iron reduction device with full preheating and gas phase prereduction, including: iron ore powder preparation system, pulverized coal preparation system, high temperature gasification melting furnace 16, medium temperature carbonization furnace 20, ash hopper 17, first-grade iron Ore powder separator 22, secondary iron ore powder separator 23, pre-reduction reactor 24; high-temperature gasification melting furnace 16 and medium-temperature carbonization furnace 20 are connected by a U-shaped structure, and the lower part is a public ash hopper, high-temperature gasification melting furnace 16 A burner 15 is provided at the top. The upper part of the intermediate temperature carbonization furnace 20 is connected to a coke powder separator 21. The top of the coke powder separator 21 is respectively connected to the bottom outlet of the secondary iron ore powder separator 23 and the pre-reduction reactor 24 The inlet on the side wall of the coke dust separator 21 is connected to the burner 15, the bottom outlet of the pre-reduction reactor is connected to the high-temperature gasification melting furnace 16, and the pre-reduction reactor 24 The top outlet is respectively connected with the inlet of the side wall of the secondary iron ore fine separator 23 and the outlet at the bottom of the primary iron ore fine separator 22, and the outlet on the top of the secondary iron ore fine separator 23 is connected to the primary iron ore separator 23. The inlet of the side wall of the slag separator 22 is connected, the first-level iron ore separator 22 is connected with the iron ore powder preparation system, the medium temperature carbonization furnace 20 is connected with the coal powder preparation system, and the ash hopper 17 is connected with the slag tank 18 connected.

Example 3:

The iron ore powder preparation system consists of an iron ore bin 1, a first crusher 2, a crushed ore bin 3, a first mill 4, a bag filter 5, an iron ore powder bin 6, and an iron ore powder feeder 7. Connected in turn. The above-mentioned device can grind iron ore to the required particle size and put it into the system furnace, improve the utilization rate of iron ore powder and reduce energy consumption.

Example 4:

The pulverized coal preparation system consists of a raw coal silo 8, a second crusher 9, a crushed coal silo 10, a second pulverizer 11, a coarse coal separator 12, a coarse coal silo 13, and a pulverized coal feeder 14 are sequentially connected to make. The above-mentioned device can realize the classification and utilization of coarse and fine coal powder, and at the same time realize the balance and matching of consumption between coarse and fine powder.

Example 5:

A slag conveyor 19 is provided in the slag tank 18. The above device can remove iron slag quickly and efficiently, has a high slag removal rate, and significantly reduces iron loss.

Example 6:

The high-temperature gasification melting furnace 16 has a vertical down-bed structure. The above structure can fully react the reducing gas with the preheated semi-reduced iron ore powder, and improve the yield and the quality of molten iron.

Example 7:

Compared with the existing short-process smelting reduction ironmaking system, this application has a three-stage type, namely a high-temperature gasification melting section, a medium-temperature carbonization section, and a low-temperature multi-stage gas-phase reduction and preheating section, ore powder pre-reduction preheating and coal The powder coke is produced in two reaction sections separately, which reduces the coke-iron separation process. In this embodiment, the high-temperature gasification melting furnace 16 is a liquid slag discharge, and the upper end is a coke powder feeding port to facilitate the reduction of iron ore powder.

Example 8:

The intermediate temperature carbonization furnace 20 has a vertical up-bed structure. The pulverized coal is injected from the side of the lower end of the intermediate temperature carbonization section, and the coke is produced through the carbonization activation process.

Example 9:

The side wall of the intermediate temperature carbonization furnace 20 is provided with a pulverized coal inlet. It is convenient to use different types of pulverized coal to make coke, and the obtained coke has similar physical and chemical properties, and can be used to reduce iron in the high-temperature gasification melting section.

Example 10

Coal powder is pyrolyzed and gasified to produce coal gas and coke powder;

In this embodiment, the heat source for the two-stage preheating of iron ore powder is the coal gas. The coal gas generated by gasification of pulverized coal is used to fully preheat the iron ore powder in the two-stage iron ore powder separator, which promotes the pre-reduction process of the iron ore powder. The quality of the molten iron is better. The process is shorter and the production energy consumption is lower.

Finally, it should be noted that the above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, it is still for those skilled in the art. The technical solutions described in the foregoing embodiments may be modified, or some of them may be equivalently replaced. Any modification, equivalent replacement, improvement, etc., made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. Although the specific embodiments of the present invention are described above in conjunction with the accompanying drawings, they do not limit the protection scope of the present invention. Those skilled in the art should understand that on the basis of the technical solutions of the present invention, those skilled in the art do not need to pay creative work Various modifications or variations that can be made are still within the protection scope of the present invention.

Claims

A coal gasification cooperative molten iron reduction device with full preheating and gas phase prereduction, which is characterized by comprising: iron ore powder preparation system, coal powder preparation system, high temperature gasification melting furnace, medium temperature carbonization furnace, ash hopper, and one stage Iron ore powder separator, secondary iron ore powder separator, pre-reduction reactor; high-temperature gasification melting furnace and medium-temperature carbonization furnace are connected by a U-shaped structure, the lower part is a public ash hopper, and the top of the high-temperature gasification melting furnace is equipped with a burner The upper part of the intermediate temperature carbonization furnace is connected with a coke powder separator, and the top of the coke powder separator is respectively connected with the bottom outlet of the secondary iron ore powder separator and the inlet on the side wall of the pre-reduction reactor. The bottom outlet of the powder separator is connected to the burner, the bottom outlet of the pre-reduction reactor is connected to the high-temperature gasification melting furnace, and the top outlet of the pre-reduction reactor is respectively connected to the inlet of the side wall of the secondary iron ore powder separator It is connected to the outlet at the bottom of the first-level iron ore powder separator, and the outlet at the top of the second-level iron ore powder separator is connected to the inlet of the side wall of the first-level iron ore powder separator. The device is connected with the iron ore powder preparation system, the medium temperature carbonization furnace is connected with the coal powder preparation system, and the ash hopper is connected with the slag pool.
The coal gasification cooperative molten iron reduction device with sufficient preheating and gas phase prereduction according to claim 1, wherein the iron ore powder preparation system consists of an iron ore bin, a first crusher, a crushing bin, and a second A powder mill, bag filter, iron ore powder bin, and iron ore powder feeder are connected in sequence.
The coal gasification cooperative molten iron reduction device with full preheating and gas phase prereduction according to claim 1, wherein the coal powder preparation system consists of a raw coal bunker, a second crusher, a crushed coal bunker, and a second grinding powder The machine, the coarse coal separator, the coarse coal silo, and the pulverized coal feeder are connected in sequence.
The coal gasification cooperative molten iron reduction device with sufficient preheating and gas phase prereduction according to claim 1, wherein a slag conveyor is provided in the slag tank.
The coal gasification cooperative molten iron reduction device with sufficient preheating and gas phase prereduction according to claim 1, characterized in that the high temperature gasification melting furnace is a vertical down-bed structure.
The coal gasification cooperative molten iron reduction device with sufficient preheating and gas phase prereduction according to claim 1, characterized in that the high temperature gasification melting furnace is liquid slag discharge, and the upper end is a coke powder feeding port.
The coal gasification cooperative molten iron reduction device with full preheating and gas phase prereduction according to claim 1, wherein the intermediate temperature carbonization furnace is a vertical up-bed structure.
The coal gasification cooperative molten iron reduction device with sufficient preheating and gas phase prereduction according to claim 1, characterized in that the side wall of the intermediate temperature carbonization furnace is provided with a pulverized coal inlet.
A coal gasification synergistic molten iron reduction process with sufficient preheating and gas phase prereduction is characterized in that it comprises:

Coal powder is pyrolyzed and gasified to produce coal gas and coke powder;

The coal gas undergoes a pre-reduction reaction with the two-stage preheated iron ore powder to form semi-reduced iron ore powder,

The coke powder is burned to generate H 2 and CO reducing gas, and reacts with semi-reduced iron ore powder at high temperature to generate molten iron, which is obtained.
The coal gasification and molten iron reduction process with full preheating and gas phase prereduction according to claim 9, characterized in that the heat source for the two-stage preheating of iron ore powder is the coal gas.