阅读说明：本技术 一种含铁粉料在还原性气氛中直接炼钢装置及使用方法 (Direct steelmaking device for iron-containing powder in reducing atmosphere and use method ) 是由 赵晓 于 2021-08-10 设计创作，主要内容包括：本发明实施例公开一种含铁粉料在还原性气氛中直接炼钢装置及使用方法,属于冶金的技术领域。所述装置包括炼钢池、造气塔、快速还原区、矿料投放区和控制系统；所述炼钢池设在最底部,所述炼钢池包括造渣熔剂堆,所述炼钢池底部设有钢水层,所述钢水层上设有液态渣层；所述炼钢池的上方设有快速还原区；所述快速还原区下部设有造气塔,所述快速还原区的上方设有矿料投放区；所述矿料投放区顶部的中央部位设有尾气排放口,所述尾气排放口的外侧设有造渣熔剂投放口,所述矿料投放区的侧面设有冷气口和矿粉投放口,所述矿料投放区的内部设有造渣熔剂仓和造渣熔剂投放机构；所述直接炼钢装置设有控制系统,通过传感器和控制部件与所述装置电连接。(The embodiment of the invention discloses a direct steelmaking device of iron-containing powder in reducing atmosphere and a using method thereof, belonging to the technical field of metallurgy. The device comprises a steel-making pool, a gas making tower, a rapid reduction area, an ore material feeding area and a control system; the steelmaking pool is arranged at the bottommost part and comprises a slagging flux pile, a molten steel layer is arranged at the bottom of the steelmaking pool, and a liquid slag layer is arranged on the molten steel layer; a rapid reduction area is arranged above the steelmaking pool; a gas making tower is arranged at the lower part of the rapid reduction area, and an ore material feeding area is arranged above the rapid reduction area; a tail gas discharge port is arranged in the center of the top of the mineral aggregate feeding area, a slagging flux feeding port is arranged on the outer side of the tail gas discharge port, a cold gas port and a mineral powder feeding port are arranged on the side surface of the mineral aggregate feeding area, and a slagging flux bin and a slagging flux feeding mechanism are arranged in the mineral aggregate feeding area; the direct steelmaking device is provided with a control system and is electrically connected with the device through a sensor and a control part.)

1. A direct steelmaking device of iron-containing powder in reducing atmosphere is characterized by comprising a steelmaking pool, a gas making tower, a rapid reduction area, an ore feeding area and a control system;

wherein: the steelmaking pool is arranged at the bottommost part of the device and comprises a slagging flux pile, a molten steel layer is arranged at the bottom of the steelmaking pool, and a liquid slag layer is arranged on the molten steel layer;

a rapid reduction area is arranged above the steelmaking pool;

a gas making tower is arranged beside the lower part of the rapid reduction zone, and an ore material feeding zone is arranged above the rapid reduction zone;

a tail gas discharge port is arranged in the center of the top of the mineral aggregate feeding area, a plurality of slagging flux feeding ports are arranged on the outer side of the tail gas discharge port along the circumference, a plurality of cold gas ports and a plurality of mineral powder feeding ports are uniformly arranged on the side surface of the mineral aggregate feeding area, and a slagging flux bin and a slagging flux feeding mechanism are arranged in the mineral aggregate feeding area;

the control system is arranged beside the steel-making pool, the gas-making tower, the rapid reduction area or the mineral aggregate feeding area and is electrically connected with the device through a sensor and a control part.

2. The direct steelmaking device of iron-containing powder in a reducing atmosphere of claim 1, wherein the steelmaking pool is a cylinder or a polygonal prismatic cylinder, the upper part of the steelmaking pool is directly connected with the rapid reduction zone, one side of the molten steel layer of the steelmaking pool near the bottom is provided with a tap hole, and the other side of the liquid slag layer near the molten steel layer is provided with a tap hole.

3. The apparatus for direct steelmaking in a reducing atmosphere of iron-containing powder of claim 1 wherein the slagging flux pile is a circular cone shaped solid slagging flux pile; the solid slagging flux material pile is in a conical pile shape and is formed by mixing one or more of granular or blocky limestone with the grain diameter of 5-50mm, quicklime, semi-coke, fluorite, dolomite and lump coal and then naturally falling; the solid slagging flux material pile passes through the liquid slag layer, and the bottom of the solid slagging flux material pile is suspended in the molten steel layer.

4. The direct steelmaking device of iron-containing powder in reducing atmosphere as claimed in claim 1, wherein the gas making tower is internally provided with a gas making gun and a reducing gas flow channel, and is in the shape of a truncated cone or a truncated pyramid; the outside of the gas making gun is connected with an oxygen supply device and a gas making raw material supply device, and the high temperature of the flame at the mouth of the gas making gun reaches 1800-; and the outlet of a reducing gas flow passage of the gas making tower is connected with the lower part of the rapid reduction area.

5. The apparatus for direct steelmaking in a reducing atmosphere containing iron fines as claimed in claim 4 wherein the reducing gas flow channel is flared with a downward inclination from the horizontal of 30 ° -60 °; the inclination angle with the centripetal axis is 1-16 degrees for right inclination in the northern hemisphere and 1-16 degrees for left inclination in the southern hemisphere.

6. The direct steelmaking device of iron-containing powder in a reducing atmosphere according to claim 1, wherein the rapid reduction zone is an area for reducing iron-containing powder and has a structure of a variable cross-section cylinder or a polygonal cylinder with a thin middle part and thick upper and lower ends; and at least 3 gas making towers are arranged at the lower part of the rapid reduction zone along the circumference.

7. The direct steelmaking device of iron-containing powder in a reducing atmosphere according to claim 1, wherein the ore charging area is of a frustum shape with a large bottom and a small top, and a tail gas discharge port is formed in the central part of the top of the ore charging area; at least 1 slagging flux feeding opening is arranged on the outer side of the tail gas discharge opening along the circumference; the outside in mineral aggregate input area evenly is provided with 2 at least powdered ore input openings, the outside in mineral aggregate input area evenly is provided with 2 at least cold gas mouths, the inside in mineral aggregate input area is provided with slagging scorification flux storage storehouse and slagging scorification flux input mechanism.

8. The apparatus for direct steelmaking in a reducing atmosphere containing iron fines of claim 1 where the control system is comprised of a hardware system and control software electrically connected to the apparatus through sensors and control components.

9. Use of the iron-containing powder according to any one of claims 1 to 8 in a direct steelmaking plant in a reducing atmosphere, characterized in that it comprises the following steps:

opening a slagging flux feeding opening through a control system, mixing slagging flux materials, then loading the materials into a slagging flux storage bin, and enabling the slagging flux materials to enter a steel-making pool from the slagging flux storage bin to form a slagging flux pile with the height of 1-3m at the bottom;

step two, drying the gas making raw material with the average grain diameter of less than 0.1mm until the moisture content is less than or equal to 1 wt%, and then filling the gas making raw material into a gas making raw material supply device;

thirdly, starting the gas making gun through an ignition device of the gas making gun, and adjusting an oxygen supply device and a gas making raw material supply device to enable CO + H in the components of the gas made₂>90% of temperature>1800℃；

Drying the iron-containing powder until the moisture content is less than or equal to 1 wt.%, starting a mineral powder feeding port to feed the iron-containing powder, wherein the particle size of the iron-containing powder is less than 1mm, the average particle size is 0.074mm, and the TFe content of the total iron is 50-70 wt.%;

fifthly, during the falling of the device, the iron-containing powder and the reducing gas generated by the ascending gas making gun generate heat transfer and mass transfer reaction in the rapid reduction area, and then fall onto the surface of the slagging flux pile in the steel-making pool, and the unreduced part of the iron-containing powder in the rapid reduction area is further reduced on the surface of the slagging flux pile and the reducing gas generated by the gas making gun;

step six, finishing final reduction of the molten iron and the reducing gas, finishing impurity removal reaction with a slagging flux pile to generate final slag, and then separating slag and steel;

and step seven, discharging the molten steel and the slag liquid from the steel tapping hole and the slag tapping hole regularly, and timely discharging generated waste gas through a tail gas discharge port.

10. The use method according to claim 9, wherein the molten steel in the seventh step is C: <0.5 wt.%, S: <0.02 wt.%, P: <0.02 wt.% of a crude steel; the binary alkalinity of the slag liquid is 1.3-2.0.

Technical Field

The invention belongs to the technical field of metallurgy, and relates to a direct steelmaking device of iron-containing powder in reducing atmosphere and a using method thereof.

Background

Coking, sintering/pelletizing → blast furnace → converter is the main process of crude steel production at present, the process integrates four process links of sintering (or pelletizing), coking, blast furnace ironmaking and converter oxidation steelmaking, and has the defects of long production process, high energy consumption, serious environment pollution depending on coke resources and the like. When the current global environmental pollution and resource and energy shortage problem is getting more serious, the implementation of energy conservation and emission reduction and the implementation of clean production become the necessary routes for the continuous development of the global steel industry.

The traditional steelmaking process adopts an oxygen converter and an electric furnace steelmaking process. The oxygen converter adopts blast furnace molten iron as a raw material to carry out converting to obtain qualified molten steel, and has the advantages of multiple production units, large scale and long production period. The blast furnace molten iron adopted by the oxygen converter has high carbon content (usually 2.5-4.3%), contains more impurities such as silicon, manganese, phosphorus, sulfur and the like, not only needs a slagging flux, but also needs high-purity oxygen blowing, and the heat is lost during the transfer of the molten iron. The electric furnace steelmaking mainly adopts recycled scrap steel, and the process for obtaining qualified molten steel by smelting in the electric furnace by using electric energy as a heat source has the advantages of simple process flow and few production links and periods. Because scrap steel needs to be melted, a large amount of electric energy needs to be consumed, and both the scrap steel and the scrap steel need to build independent steelmaking equipment, so that the investment cost is huge.

Aiming at the problems of high pollution and high energy consumption of the traditional blast furnace ironmaking process, the smelting reduction ironmaking technology is developed in recent years because the dependency on high-pollution and high-energy-consumption processes such as agglomeration, sintering, coking and the like can be reduced, and becomes an important technical approach for realizing energy conservation, emission reduction and clean production in the steel industry, such as COREX, FINEX, HIsmelt and the like. The COREX process uses an upper pre-reduction shaft furnace to pre-reduce iron ore to obtain metallized pellets (DRI) with a metallization rate of 70-90%, and then the DRI is fed into a lower melter-gasifier for final reduction. The process still needs to rely on lump ore, pellet ore, sinter ore and part of coke to maintain smooth operation of the furnace condition in the production process. The FINEX process uses fine ore as raw material, adopts a multi-stage fluidized state reactor to complete iron ore pre-reduction, obtains reduced iron powder with the metallization rate of about 90%, and the reduced iron powder and the fine coal are added into a melting gasification furnace as furnace charge after being subjected to hot briquetting for melting final reduction. The HIsmelt process takes fine ore as a main raw material, a cyclone melting furnace is adopted to carry out flash smelting on the fine ore, a flux and coal powder are blown into the cyclone melting furnace along the tangential direction of a furnace body by taking oxygen as a carrier, the fine ore is reduced and melted in the movement process, and then flows along the furnace wall and drops into the melting reduction furnace for final reduction.

The processes obviously carry out reduction iron making and melting final reduction steel making through different devices, wherein iron-containing powder is reduced firstly and then briquetted, and then the steel making is reduced, obviously, the processes are complex, and the utilization rate of the devices is low. Although the flash smelting efficiency is high, the cyclone melting furnace and the smelting reduction furnace are different in device structure, the requirement on the blowing performance of the cyclone melting furnace blown along the tangential direction of the furnace body is very high, the corrosion of refractory materials is serious, the service life of a furnace lining is short, and the industrial large-scale production and popularization cannot be carried out.

The flash iron-making technologies disclosed in patents CN106086280A, CN102690919A, CN103993115A, etc. integrate the processes of reduction, melting, slag-making, etc. into one body, and have the advantages of simplified equipment and easy mass production, but the product molten iron has high carbon content (> 2.0%), and impurities such as Si, Mn, P, S, etc. cannot be effectively removed, and crude steel cannot be directly produced. Other patents CN101906501A and CN108374067A propose a process for direct steelmaking using fine ore and coal oxygen, in which iron ore powder is pre-reduced and then sprayed into a steelmaking furnace together with coal powder and oxygen to make steel. In particular, the device for direct steel making by rapid reduction in CN108374067A includes an iron ore powder pretreatment system, a rapid reduction furnace system and a steel making furnace system, and obviously, reduction iron making and melting final reduction steel making are also performed by different devices.

To sum up, the current-stage smelting reduction iron-making/direct steel-making method can solve the problems of long steel production flow, high energy consumption and serious pollution to a certain extent, but the process still adopts the two-step process of traditional reduction iron-making and oxidation steel-making; the reduction process and the oxidation process are implemented in different devices or containers, so that the defects of high equipment investment and high fault of connecting equipment exist.

Disclosure of Invention

The invention solves the technical problems that the traditional blast furnace iron making and converter steel making have large energy consumption and serious environmental pollution and need two steps; although the smelting reduction iron-making technology exists, reduction iron-making and oxidation steel-making are carried out by different devices, the production flow is long, the energy consumption is high, the pollution is serious, the occupied area of different equipment is large, and the synergy rate is low.

In order to solve the technical problems, the invention provides the following technical scheme:

a direct steelmaking device of iron-containing powder in reducing atmosphere comprises a steelmaking pool, a gas making tower, a rapid reduction area, an ore material feeding area and a control system;

wherein: the steelmaking pool is arranged at the bottommost part of the device and comprises a slagging flux pile, a molten steel layer is arranged at the bottom of the steelmaking pool, and a liquid slag layer is arranged on the molten steel layer;

a rapid reduction area is arranged above the steelmaking pool;

a gas making tower is arranged beside the lower part of the rapid reduction zone, and an ore material feeding zone is arranged above the rapid reduction zone;

a tail gas discharge port is arranged in the center of the top of the mineral aggregate feeding area, a plurality of slagging flux feeding ports are arranged on the outer side of the tail gas discharge port along the circumference, a plurality of cold gas ports and a plurality of mineral powder feeding ports are uniformly arranged on the side surface of the mineral aggregate feeding area, and a slagging flux bin and a slagging flux feeding mechanism are arranged in the mineral aggregate feeding area;

the control system is arranged beside the steel-making pool, the gas-making tower, the rapid reduction area or the mineral aggregate feeding area and is electrically connected with the device through a sensor and a control part.

Preferably, the steelmaking pool is a cylinder or a polygonal prism cylinder, the upper part of the steelmaking pool is directly connected with the rapid reduction zone, one side of a molten steel layer of the steelmaking pool, which is close to the bottom, is provided with a steel outlet, and the other side of a liquid slag layer, which is close to the molten steel layer, is provided with a slag outlet.

Preferably, the slagging flux pile is a solid slagging flux pile with an arc cone shape; the solid slagging flux material pile is in a conical pile shape and is formed by mixing one or more of granular or blocky limestone with the grain diameter of 5-50mm, quicklime, semi-coke, fluorite, dolomite and lump coal and then naturally falling; the solid slagging flux material pile passes through the liquid slag layer, and the bottom of the solid slagging flux material pile is suspended in the molten steel layer.

Preferably, the gas making tower is internally provided with a gas making gun and a reducing gas flow channel which are in a shape of a cone frustum or a pyramid frustum; the gas making gun is externally connected with an oxygen supply device and a gas making raw material supply device, the high temperature of the flame at the mouth of the gas making gun reaches 1800-; and the outlet of a reducing gas flow passage of the gas making tower is connected with the lower part of the rapid reduction area.

Preferably, the gas making raw material supply device supplies gas making raw materials, and the gas making raw materials include, but are not limited to, pulverized coal, natural gas, hydrogen, biomass fuel and the like.

Preferably, the reducing gas generated by the gas making gun contains a certain proportion of CO and H₂Small amount of H₂O，CO₂And N₂。

Preferably, the main reactions of the fast reduction zone are:

[FeO]+H₂(g)＝[Fe]+H₂O(g)

[FeO]+CO(g)＝[Fe]+CO₂(g)

the main reactions in the slagging flux pile area are:

(SiO₂)+2(CaO)＝(2CaO·SiO₂)

[FeS]+(CaO)＝(CaS)+[FeO]

(P₂O₅)+4(CaO)＝(4CaO·P₂O₅)。

preferably, the reducing gas flow channel is in a bell mouth shape, and the downward inclination angle of the reducing gas flow channel and the horizontal plane is 30-60 degrees; the inclination angle with the centripetal axis is 1-16 degrees for right inclination in the northern hemisphere and 1-16 degrees for left inclination in the southern hemisphere.

Preferably, the rapid reduction area is an area for reducing the iron-containing powder, and the structure is a variable-section cylindrical or polygonal cylindrical structure with a thin middle part and thick upper and lower ends; and at least 3 gas making towers are arranged at the lower part of the rapid reduction zone along the circumference.

Preferably, the mineral aggregate feeding area is of a frustum shape with a large lower part and a small upper part, and a tail gas discharge port is formed in the central part of the top of the mineral aggregate feeding area; at least 1 slagging flux feeding opening is arranged on the outer side of the tail gas discharge opening along the circumference; the outside in mineral aggregate input area evenly is provided with 2 at least powdered ore input openings, the outside in mineral aggregate input area evenly is provided with 2 at least cold gas mouths, the inside in mineral aggregate input area is provided with slagging scorification flux storage storehouse and slagging scorification flux input mechanism.

Preferably, the control system consists of a hardware system and control software, and is electrically connected with the device through a sensor and a control component.

Preferably, the control system is electrically connected with the gas making tower, the cold air port, the mineral powder feeding port, the slagging flux feeding port and the slagging flux feeding mechanism.

The use method of the direct steelmaking device of the iron-containing powder in the reducing atmosphere comprises the following steps:

opening a slagging flux feeding opening through a control system, mixing slagging flux materials, then loading the materials into a slagging flux storage bin, and enabling the slagging flux materials to enter a steel-making pool from the slagging flux storage bin to form a slagging flux pile with the height of 1-3m at the bottom;

step two, drying the gas making raw material with the average grain diameter of less than 0.1mm until the moisture content is less than or equal to 1 wt%, and then filling the gas making raw material into a gas making raw material supply device;

thirdly, starting the gas making gun through an ignition device of the gas making gun, and adjusting an oxygen supply device and a gas making raw material supply device to enable CO + H in the components of the gas made₂>90% of temperature>1800℃；

Drying the iron-containing powder until the moisture content is less than or equal to 1 wt.%, starting a mineral powder feeding port to feed the iron-containing powder, wherein the particle size of the iron-containing powder is less than 1mm, the average particle size is 0.074mm, and the TFe content of the total iron is 50-70 wt.%;

fifthly, during the falling of the device, the iron-containing powder and the reducing gas generated by the ascending gas making gun generate heat transfer and mass transfer reaction in the rapid reduction area, and then fall onto the surface of the slagging flux pile in the steel-making pool, and the unreduced part of the iron-containing powder in the rapid reduction area is further reduced on the surface of the slagging flux pile and the reducing gas generated by the gas making gun;

step six, finishing final reduction of the molten iron and the reducing gas, finishing impurity removal reaction with a slagging flux pile to generate final slag, and then separating slag and steel;

and step seven, discharging the molten steel and the slag liquid from the steel tapping hole and the slag tapping hole regularly, and timely discharging generated waste gas through a tail gas discharge port.

Preferably, the surface of the slagging flux pile in the first step is an inwards concave arc surface, and the soft-melted steel slag mixture slowly flows from the top of the pile to the bottom of the pile along the arc surface under the action of gravity and reversely convects with the high-temperature reducing gas to carry out heat and mass exchange; when the steel slag mixture flows downwards, the steel slag mixture reacts with the slagging flux on the surface of the slagging flux pile to remove impurities such as sulfur, phosphorus and the like in the molten steel and generate high-alkalinity final slag.

Preferably, the molten steel in the step seven is C: <0.5 wt.%, S: <0.02 wt.%, P: <0.02 wt.% of a crude steel; the binary alkalinity of the slag liquid is 1.3-2.0.

The technical scheme provided by the embodiment of the invention at least has the following beneficial effects:

in the scheme, the iron-containing powder is directly used for making steel in a reducing atmosphere, the traditional process flow of coking, sintering and pelletizing of a blast furnace and the converter steelmaking method are abandoned, the iron-containing powder is directly used as a raw material and is subjected to reduction reaction with reducing gas in a rapid reduction zone, a small amount of unreduced iron oxide is subjected to final reduction in a slagging flux pile, and impurity removal reactions such as desulfurization and dephosphorization are simultaneously completed, so that crude steel can be directly and efficiently produced in one device, coke resources are not relied on, and the high-energy-consumption process is reduced; a large amount of steel making devices are not needed, the occupied area of a factory is small, and a large amount of capital investment is saved.

The iron-containing powder is directly steelmaking in a reducing atmosphere, the gas making raw material needs to be sprayed with high-temperature reducing gas through a gas making gun, the high-temperature reducing gas directly acts on a slagging flux pile and a steel slag mixture flowing downwards along the slagging flux pile to provide heat for the steel slag mixture and the slagging flux pile, the temperature of the steel slag mixture is favorably improved, the melting of lime is favorably realized, the stagnation period is shortened, the slagging process is accelerated, and the heat loss is less; then the high-temperature reducing gas rises through the rapid reducing region, and meets the falling iron-containing powder in a countercurrent manner in the rapid reducing region, and simultaneously performs heat transfer and mass transfer reactions, so that the contact reaction is sufficient, and the reaction efficiency is high.

The iron-containing powder is directly steelmaking in a reducing atmosphere, a steelmaking pool is arranged at the bottom of a furnace body, iron and iron ore soft melts falling after reduction reaction fall on the surface of a slagging flux pile together, the unreduced part of the iron-containing powder in a rapid reduction area can be further reduced with high-temperature reducing gas, the final reduced steel slag mixture is subjected to impurity removal reactions such as dephosphorization and desulfurization with the slagging flux to generate final slag, then slag and steel are separated, direct steelmaking can be realized in one device, a large amount of independent investment of steelmaking equipment is not needed, and the fund and the area of a site are greatly saved.

The invention is based on the iron-containing powder integrated reduction and slagging in the rapid reduction area and the slagging flux pile, carries out unique design on the structure and the process of the direct steelmaking equipment, creates a flow field and a temperature field which are beneficial to heat transfer and mass transfer in the device, and thus achieves the purpose of integrated direct steelmaking based on the slagging flux pile in the device under the reducing atmosphere.

In a word, the smelting process of the invention is carried out around the slagging flux pile in the steelmaking pool, and the slagging flux is sufficient and excessive in the whole smelting process; the impurities such as sulfur, phosphorus and the like and acidic oxides which need to be removed complete various chemical reactions on the surface of an excessive slagging flux (alkaline oxide) pile to generate low-melting-point final slag, and the low-melting-point final slag is discharged into a steel-making pool.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic structural view of a direct steelmaking apparatus in a reducing atmosphere containing iron powder according to the present invention.

The reference numerals are explained below:

1. a steel-making pool; 11. slagging flux pile; 12. a molten steel layer; 121. a steel tapping hole; 13. a liquid slag layer; 131. a slag outlet;

2. a gas making tower; 21. an air gun; 22. a reducing gas flow channel;

3. a fast reduction zone;

4. a mineral aggregate feeding area; 41. a cold air port; 42. a mineral powder feeding port; 43. a slagging flux storage bin; 44. a slagging flux feeding port; 45. a tail gas discharge port; 46. a slagging flux feeding mechanism;

5. and (5) controlling the system.

Detailed Description

In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1, an embodiment of the present invention provides a direct steelmaking device of iron-containing powder in a reducing atmosphere, the device includes a steelmaking pool 1, a gas making tower 2, a rapid reduction zone 3, an ore material charging zone 4 and a control system 5, the steelmaking pool 1 is disposed at the bottommost portion of the device, the steelmaking pool 1 includes a centrally disposed slagging flux pile 11, a molten steel layer 12 is disposed at the bottom of the slagging flux pile 11, a liquid slag layer 13 is disposed on the upper layer of the molten steel layer 12, the rapid reduction zone 3 is disposed above the slagging flux pile 11, the gas making tower 2 is disposed beside the lower portion of the rapid reduction zone 3, the ore material charging zone 4 is disposed above the rapid reduction zone 3, and the control system 5 controls measurement and control units distributed at different positions through electrical connection.

The steelmaking pool 1 is a cylinder or a polygonal prism cylinder, the upper part of the steelmaking pool 1 is directly connected with the rapid reduction zone 3, one side of a molten steel layer 12 of the steelmaking pool 1, which is close to the bottom, is provided with at least 1 steel outlet 121, and the other side of a liquid slag layer 13, which is close to the molten steel layer 121, is provided with at least 1 slag outlet 131.

The slagging flux pile 11 is a solid slagging flux material pile with an arc cone shape; the solid slagging flux material pile is in a conical pile shape with the height of 1-3m, and is formed by mixing one or more of granular or blocky limestone with the grain diameter of 5-50mm, quick lime, semi-coke, fluorite, dolomite and lump coal and then naturally falling. The solid slagging flux material pile is preferably granular limestone with the grain diameter of 20mm, preferably blocky quicklime with the grain diameter of 30mm, preferably granular semi-coke with the grain diameter of 15mm, preferably blocky semi-coke, fluorite, dolomite and lump coal with the grain diameter of 40mm, preferably granular limestone with the grain diameter of 33mm, quicklime, semi-coke and fluorite; the height of the conical pile is preferably 1.5m, 2.5m, 1m, 3 m.

The gas making tower 2 is internally provided with a gas making gun 21 and a reducing gas flow passage 22 which are in a cone frustum shape; the exterior of the gas making gun 21 is connected with an oxygen supply device and a gas making raw material supply device; the high temperature of the flame at the muzzle of the air making gun 21 reaches 1800-; the gas making gun 21 sprays flame of gas making raw material combustion inwards, high-temperature reducing gas is generated through incomplete combustion, and the high-temperature reducing gas is directly sprayed to the side surface of the slagging flux pile 11; the outlet of the reducing gas flow passage 22 of the gas making tower 2 is connected with the lower part of the rapid reduction area 3.

The gas making raw material supply device supplies gas making raw materials, and the gas making raw materials include but are not limited to pulverized coal, natural gas, hydrogen, biomass fuel and the like.

The reducing gas generated by the gas making gun 21 contains CO and H in a certain proportion₂Small amount of H₂O，CO₂And N₂。

The reducing gas flow passage 22 is in a bell mouth shape, and the downward inclination angle with the horizontal plane is 30-60 degrees, preferably 45 degrees, 40 degrees, 50 degrees, 30 degrees and 60 degrees; the inclination angle with the centripetal axis is 1-16 degrees for right inclination in the northern hemisphere and 1-16 degrees for left inclination in the southern hemisphere, and 8 degrees, 11 degrees and 5 degrees are preferred.

The rapid reduction zone 3 is an area for reducing iron-containing powder, and is structurally in the shape of a variable cross section cylinder with a thin middle part and thick upper and lower ends, and the shape of the variable cross section is used for controlling a flow field to operate according to set parameters; 3-36 gas making towers are uniformly arranged at the lower part of the rapid reduction zone 3 along the circumference.

The mineral aggregate feeding area 4 is of a frustum shape with a large lower part and a small upper part, and a tail gas discharge port 45 is formed in the central part of the top of the mineral aggregate feeding area 4; the outer side of the tail gas discharge port is circumferentially provided with 1-3 slagging flux feeding ports 44, the outer side of the mineral aggregate feeding area 4 is uniformly provided with 2-16 mineral powder feeding ports 42, the outer side of the mineral aggregate feeding area 4 is uniformly provided with 2-18 cold air ports 41 for introducing cooling gas and controlling the temperature of tail gas within a set range, and the inner part of the mineral aggregate feeding area 4 is provided with a slagging flux storage bin 43 and a slagging flux feeding mechanism 46.

The control system 5 consists of a hardware system and control software and is electrically connected with the device through a sensor and a control component.

The embodiment of the invention provides a using method of a direct steelmaking device of iron-containing powder in a reducing atmosphere, which comprises the following steps:

step one, opening a slagging flux feeding port 44 through a control system 5, mixing slagging flux materials, then feeding the mixed materials into a slagging flux storage bin 43, and controlling a slagging flux feeding mechanism 46 to enable the slagging flux materials to enter a steel-making pool 1 from the slagging flux storage bin 43 to form a slagging flux pile 11 at the bottom;

step two, drying the gas making raw material with the average grain diameter of less than 0.1mm until the moisture content is less than or equal to 1 wt%, and then filling the gas making raw material into a gas making raw material supply device;

step three, starting the gas making gun 21 through an ignition device of the gas making gun 21, and adjusting an oxygen supply device and a gas making raw material supply device to enable CO + H in the components of the gas made₂>90% of temperature>1800℃；

Step four, drying the iron-containing powder until the moisture content is less than or equal to 1 wt.%, starting a mineral powder feeding port 42 for feeding, wherein the particle size of the iron-containing powder is less than 1mm, the average particle size is 0.074mm, and the TFe content of total iron is 50-70 wt.%;

fifthly, during the falling of the iron-containing powder in the device, the iron-containing powder and the reducing gas generated by the ascending gas making gun 21 are subjected to heat transfer and mass transfer reaction in the rapid reduction area 3 and then fall onto the surface of the slagging flux pile 11 in the steel making pool 1, and the unreduced part of the iron-containing powder in the rapid reduction area 3 is further reduced on the surface of the slagging flux pile 11 and the reducing gas generated by the gas making gun 21;

sixthly, the steel slag mixture after final reduction and the slagging flux pile 11 are subjected to impurity removal reaction to generate final slag, and then slag and steel are separated;

and seventhly, discharging the molten steel and the slag liquid from the steel outlet 121 and the slag outlet 131 periodically, timely discharging the generated tail gas through a tail gas discharge port 45, and introducing cold gas into the tail gas through a cold gas port 41 to adjust the temperature of the tail gas.

The surface of the slagging flux pile 11 in the first step is an inward concave arc surface, and the soft-melted steel slag mixture slowly flows from the top of the pile to the bottom of the pile along the arc surface under the action of gravity and reversely convects with high-temperature reducing gas to carry out heat and mass exchange; when the steel slag flows downwards, the steel slag reacts with the slagging flux on the surface of the slagging flux pile 11 to remove impurities such as sulfur, phosphorus and the like in the molten steel and generate high-alkalinity final slag.

The molten steel in the seventh step is C: <0.5 wt.%, S: <0.02 wt.%, P: <0.02 wt.% of a crude steel; the binary alkalinity of the slag liquid is 1.3-2.0.

In the scheme, the iron-containing powder is directly used for steelmaking in a reducing atmosphere, the traditional coking, sintering and pelletizing process flow and the flash smelting method of a blast furnace are abandoned, the iron-containing powder is directly used as a raw material and is subjected to reduction reaction with reducing gas in a rapid reduction zone, a small amount of unreduced iron oxide is subjected to final reduction in a slagging flux pile, and impurity removal reactions such as desulfurization and dephosphorization are simultaneously completed, so that crude steel can be directly and efficiently produced in one device, coke resources are not relied on, and the high-energy-consumption process is reduced; a large amount of steel making devices are not needed, the occupied area of a factory is small, and a large amount of capital investment is saved.

The iron-containing powder is directly used for steelmaking in a reducing atmosphere, the gas making raw material needs to be sprayed with high-temperature reducing gas through a gas making gun, the high-temperature reducing gas directly acts on a slagging flux pile to provide heat for the slagging flux pile, so that lime is melted, the stagnation period is shortened, the slagging process is accelerated, and the heat loss is small; then the high-temperature reducing gas rises through the rapid reducing region, and meets the falling iron-containing powder in a countercurrent manner in the rapid reducing region, and simultaneously performs heat transfer and mass transfer reactions, so that the contact reaction is sufficient, and the reaction efficiency is high.

The iron-containing powder is directly steelmaking in a reducing atmosphere, a steelmaking pool is arranged at the bottom of a furnace body, falling iron and iron ore soft melts after reduction reaction fall on the surface of a slagging flux pile together, the unreduced part of the iron-containing powder in a rapid reduction area can be further reduced with high-temperature reducing gas to generate molten iron, finally, all iron oxides and the high-temperature reducing gas can be subjected to final reduction, and are subjected to impurity removal reactions such as dephosphorization and desulfurization with the slagging flux to generate final slag, so that slag and steel are separated, direct steelmaking can be realized in one device, a large amount of independent investment of steelmaking equipment is not needed, and the fund and the area of a site are greatly saved.

In a word, the smelting process of the invention is carried out around the slagging flux pile in the steelmaking pool, and the slagging flux is sufficient and excessive in the whole smelting process; the impurities such as sulfur, phosphorus and the like and the acidic oxides which need to be removed complete various chemical reactions on the surface of the excessive slagging flux (alkaline oxide) pile to generate low-melting-point final slag, and the low-melting-point final slag is discharged out of the steel-making pool. The unique design of the structure and the process of the direct steelmaking equipment is based on the integrated reduction and slagging of the iron-containing powder in the rapid reduction area and the slagging flux pile, and a flow field and a temperature field which are beneficial to heat transfer and mass transfer in the device are created, so that the aim of integrated direct steelmaking is fulfilled based on the slagging flux pile in the device under the reducing atmosphere.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.