CN1724695A - Method of manufacturing low carbon sponge iron using microwave vertical furnace - Google Patents

Method of manufacturing low carbon sponge iron using microwave vertical furnace Download PDF

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Publication number
CN1724695A
CN1724695A CNA2005100125084A CN200510012508A CN1724695A CN 1724695 A CN1724695 A CN 1724695A CN A2005100125084 A CNA2005100125084 A CN A2005100125084A CN 200510012508 A CN200510012508 A CN 200510012508A CN 1724695 A CN1724695 A CN 1724695A
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powder
microwave
sponge iron
iron
shaft furnace
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CN100398669C (en
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陈津
任瑞刚
刘浏
周渝生
刘金营
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Taiyuan University of Technology
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Taiyuan University of Technology
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Abstract

The invention relates to a method to make low carbon sponge iron by microwave shaft furnace. It adopts iron ore powder as raw material, common soft coal dust or anthracite dust as reducer to gain high quality low carbon sponge. It uses the feature that the iron ore powder, carbon powder, and lime powder has selective absorbing to microwave. Under the condition of sealing and high temperature, and under the effect of microwave generator, heater, and adjustor, it would take carbon heat self-reduction by absorbing the heat produced by microwave generator to gain low carbon sponge iron. The method has simple technology, shortens the reduction time period, saves coking coal and coke resource, and reduces environment pollution. The degree of metallization could reach 90-98%, and the carbon content could be lower than 0.5%. It is the ideal method to make low carbon sponge iron.

Description

Method for preparing low-carbon sponge iron by using microwave shaft furnace
Technical Field
The invention relates to a method for preparing low-carbon sponge iron by using a microwave shaft furnace, belonging to the technical field of smelting and preparing sponge iron in ferrous metallurgy.
Background
The blast furnace iron-making method is the most economical method for preparing iron, has the history of over 400 years, takes iron ore as raw material and coke made from coking coal as smelting energy and reducing agent, and is also used for hundreds of years.
In the process of blast furnace iron making, a large amount of coke is consumed, the coking coal for making coke only accounts for 5% of the total storage amount of coal resources in the world, the coking coal is the best among coal varieties, the combustion performance and the combustion heat are very superior, the demand on iron is greatly increased along with the development of modern industry, and the coking coal coke directly influences the development of the steel industry.
Blast furnace ironmaking processes also have many technical deficiencies in themselves, such as: the method has high dependence on blocky iron-containing ores and cokes, serious environmental pollution in the coking and agglomeration process, complex process flow, low iron purity, high carbon content and more impurities, and seriously restricts the development of the blast furnace ironmaking process.
Sponge iron is a porous, low-density and spongy iron substance, is a high-quality raw material for electric furnace or converter steelmaking, is a metallic iron product obtained by reducing iron ore at a solid softening temperature, is lower in reduction temperature, higher in speed and less in impurities than the high-furnace ironmaking temperature, and is an essential high-quality raw material in the steelmaking process.
Disclosure of Invention
Object of the Invention
The invention aims to overcome the defects of the background art, adopts a brand new method for smelting iron, prepares low-carbon sponge iron by using a microwave shaft furnace, does not use coke as an energy source and a reducing agent, does not need a coke coal coking carbon process, but uses common bituminous coal powder or anthracite powder with abundant reserves as the energy source and the reducing agent, uses lime powder as a flux, carries out reduction smelting in a microwave vertical heating reduction furnace, utilizes the characteristic that iron ore powder, coal powder and lime powder have selective absorption on microwaves, and carries out carbon heat self-reduction by absorbing the heat generated by the microwaves by self under the closed high-temperature condition to obtain the low-carbon sponge iron, thereby achieving the purposes of saving coke coal coke, simplifying the process flow, reducing environmental pollution and improving the reduction reaction speed, so that the sponge iron product has low carbon content, high metallization rate and good quality.
Technical scheme
The invention is refined by the following chemical substances, and the combination proportion of the chemical substances is as follows:
measured in kilograms and liters
Iron ore powder: 72.5 kg. + -. 7.5 kg
Pulverized coal: 20 kg. + -. 5 kg
Lime powder: 7.5 kg. + -. 2.5 kg
The preparation method of the invention comprises the following steps:
1) selecting raw materials
The iron ore powder, the coal powder and the lime powder required for preparing the low-carbon sponge iron are carefully selected, and the purity is controlled as follows:
iron ore powder: the iron content is more than 65 percent, and the water content is less than 5 percent
Coal powder: the carbon content is more than 75 percent, and the water content is less than 2 percent
Lime powder: contains calcium oxide more than 80% and water content less than 1%
2) Fine grinding of raw materials
And (4) finely grinding the carefully selected iron ore powder, coal powder and lime powder twice in a dry ball mill respectively.
3) Sieving and fineness control
Sieving the finely ground iron ore powder, coal powder and lime powder by using a screen respectively, and controlling the fineness of the fine ground iron ore powder, coal powder and lime powder;
iron ore powder: sieving with 150 mesh sieve to obtain fine powder with particle size of 0.01-0.5mm
Coal powder: sieving with 80 mesh sieve to obtain fine powder with particle size of 0.01-2mm
Lime powder: sieving with 100 mesh sieve to obtain fine powder with particle size of 0.01-1mm
4) Mixing, blending and mixing
Preparing raw materials of the sieved iron ore powder, the coal powder and the lime powder according to a combination ratio, and mixing in a special container.
5) Stirring the mixture
And stirring the mixed raw material fine powder in a special stirrer repeatedly and uniformly.
6) Microwave shaft furnace preheating
Preheating a microwave shaft furnace used for smelting at the preheating temperature of 300 +/-10 ℃ for 30-40 minutes.
7) Layered fabric
The fine powder of the raw materials which are mixed and stirred evenly is put into a microwave shaft furnace in layers, and the materials are distributed evenly and loosely with gaps according to the structural volume of the microwave shaft furnace.
8) Microwave shaft furnace smelting
The closed microwave shaft furnace is provided with each part in a quasi-working state;
starting a microwave generator, a microwave regulator and a microwave heater, wherein the power of the microwave generator is 25 kilowatts +/-0.5 kilowatts, and the frequency is 2450 megahertz:
the temperature of the microwave shaft furnace is increased from 300 ℃ to 1050 ℃ to 1250 ℃, and the temperature is kept constant for 5 to 10 minutes;
uniformly mixing iron ore powder, coal powder and lime powder, and absorbing heat generated by microwaves in a closed microwave shaft furnace to perform carbon-heat self-reduction to generate solid sponge iron;
in the smelting process of the closed high-temperature microwave shaft furnace, a chemical reaction is generated, and the chemical reaction formula is as follows:
in the formula:
Fe3O4: magnetite powder
5CHmOn: pulverized coal
CaO: lime powder
H2O: water (W)
FeS: iron sulfide
4 Fe: metallic iron
And (2) CaS: calcium sulfide
5 CO: carbon monoxide
5H2mOn: hydroxide compound
9) Cooling under nitrogen protection
After smelting, placing the solid sponge iron in a special cooling box, continuously inputting nitrogen into the cooling box, naturally cooling under the protection of the nitrogen, cooling from 1250 ℃ to 20 +/-3 ℃ for 12 hours, and preventing oxygen from entering.
10) Magnetic separation and purification
Purifying the prepared sponge iron by using special dry magnetic separation equipment, and shaving off impurities in the sponge iron;
finely grinding the sponge iron into powder, sieving the powder by using a 180-mesh sieve, and repeatedly carrying out fine grinding and sieving to ensure that the powder particles are uniform and refined;
placing the powdery sponge iron obtained by fine grinding and sieving in a dry type permanent magnetic separator, and carrying out magnetic separation under a high-intensity magnetic field with the magnetic field intensity of 1.5-2 ten thousand gausses.
11) Detection, comparison and analysis
And (3) detecting, testing, analyzing and comparing the low-carbon sponge iron obtained after magnetic separation and purification, detecting the components, purity, impurities, luster and morphology of the low-carbon sponge iron, and analyzing and detecting the low-carbon sponge iron item by item.
12) And store it
The low-carbon sponge iron powder qualified in smelting detection needs to be stored in a dry and clean environment by a special container, the storage temperature is 20 +/-3 ℃, and the low-carbon sponge iron powder needs to be waterproof, moistureproof, oxidation-resistant and acid-base corrosion-resistant.
The microwave shaft furnace mainly structurally comprises: the device comprises a furnace body, a feeding hopper, a microwave generator, a microwave regulator, a microwave heater, a discharging hopper and a cooling box; the microwave shaft furnace body 1 is externally provided with a microwave heater 2, the microwave heater 2 is symmetrically provided with a microwave generator 3 and a microwave regulator 4 at the left side and the right side, and the middle parts are connected by a lead 31; the upper part of the furnace body 1 is provided with a sealing cover 6, and the upper part of the sealing cover 6 is provided with a feeding hopper 5; the lower part of the furnace body 1 is a furnace bottom 7, the bottom of the furnace body 1 is a control base 8, the lower part of the control base 8 is a discharge hopper 9, the lower part of the discharge hopper 9 is aligned with a cooling box 10, the right side part of the cooling box 10 is connected with a nitrogen pipe 12, and the nitrogen pipe 12 is connected with a nitrogen source 11; the furnace body 1 is internally provided with a furnace wall 13, a furnace chamber 14 is arranged in the furnace wall 13, and the furnace chamber 14 is communicated with the charging hopper 5, the sealing cover 6, the furnace bottom 7, the control base 8 and the discharging hopper 9.
The preheating temperature of the microwave shaft furnace is 300 +/-10 ℃, the smelting temperature is 1050 ℃ -1250 ℃, the constant temperature heat preservation time is 5-10 minutes, the power of a microwave generator is 25 kilowatts +/-0.5 kilowatts, the frequency is 2450 megahertz, and the microwave generation time is 60 minutes +/-20 minutes.
And the nitrogen protection cooling is carried out, natural cooling is carried out in the cooling box 10, nitrogen 30 is continuously filled into the cooling box 10 through a nitrogen source 11 and a nitrogen pipe 12, the temperature is naturally cooled to 20 +/-3 ℃, and the cooling and nitrogen filling time is 12 hours.
The purification of the low-carbon sponge iron is carried out on special dry magnetic separation equipment, the upper part of the magnetic separation equipment is provided with a feed hopper 15, the feed hopper 15 is communicated with a fine grinding machine 16, and the fine grinding machine 16 is communicated with a feed delivery pipe 17; the material conveying pipe 17 is communicated with the screen 18, and an oscillator 35 is arranged in the screen 18; the screen 18 is communicated with the material conveying pipe 19, the material conveying pipe 19 is communicated with the magnetic separation container 21, a motor 32, a stirrer 20 and an impeller 28 are arranged in the magnetic separation container 21, the magnetic separation container 21 is communicated with the impurity outlet 22, and the impurity outlet 22 is communicated with the impurity box 23; the right side of the magnetic separation container 21 is communicated with a magnetic suction pipe 24, the right side of the magnetic suction pipe 24 is communicated with a magnetic separator 25, an electromagnet 26 is arranged in the magnetic separator 25, the right part of the electromagnet 26 is connected with a power supply 27, the lower part of the magnetic separator 25 is communicated with a product outlet 33, the product outlet 33 is communicated with a product box 29, and a sponge iron product 34 is stored in the product box 29; the sponge iron product 34 is magnetically separated by the magnetic separator 25 and enters the product box 29, and the impurities 36 enter the impurity box 23 through the impurity outlet 22 in the magnetic separation vessel 21.
Effect
The invention has obvious advancement compared with the background art, it has adopted a brand-new method for making sponge iron of low carbon of microwave shaft furnace, use iron ore powder as raw materials, use ordinary bituminous coal powder or anthracite powder as reducing agent, use lime powder as flux, does not use the coking coal coke that the resource is short as reducing agent, refine in the microwave shaft furnace, utilize iron ore powder, coal powder, lime powder to have this characteristic of selective absorption of microwave, under the airtight high-temperature condition, through absorbing the heat that the microwave produces by oneself and carrying on the self-reduction of carbon heat to get sponge iron, through the protective cooling of nitrogen, the magnetic separation method purifies and gets high-quality low carbon sponge iron, use the apparatus few, prepare simple technological process, reduce smelting fast, thermostatical holding time short, only 5-10 minutes, has reduced carburization time and carbon content, has saved the coking coal coke resource, has reduced the environmental pollution, the metallization rate is high and can reach 90-98%, the carbon content is low and can be less than 0.5%, the yield is high, the quality is good, and the method is an ideal method for refining the low-carbon sponge iron.
Drawings
FIG. 1 is a flow chart of a process for preparing low-carbon sponge iron
FIG. 2 is a diagram showing the relationship between the preheating, temperature rising, constant temperature keeping, temperature lowering and cooling temperatures of the microwave shaft furnace and the time coordinate
FIG. 3 is a front view of a microwave shaft furnace structure
FIG. 4 is a cross-sectional view taken along line E-F of FIG. 3
FIG. 5 is a flow chart of magnetic separation and purification equipment and process
FIG. 6 is a graph showing the variation of temperature, time and material in microwave heating
FIG. 7 is a graph showing the change of the microwave heating temperature and time with respect to the weight of the fine iron ore containing coal
FIG. 8 is a structural diagram of the structure of the heat fragmentation of the Ricoh flounder at 1250 ℃ in the microwave heating reduction
FIG. 9 is a structural view of a pumice body in the form of particles reduced at 1250 ℃ by conventional heating
The part numbers shown in the figures are listed below:
1. the device comprises a furnace body, 2, a microwave heater, 3, a microwave generator, 4, a microwave regulator, 5, a loading hopper, 6, a sealing cover, 7, a furnace bottom, 8, a control base, 9, a discharging hopper, 10, a cooling box, 11, a nitrogen source, 12, a nitrogen pipe, 13, a furnace wall, 14, a furnace chamber, 15, a feeding hopper, 16, a fine grinding machine, 17, a feeding pipe, 18, a screen, 19, a feeding pipe, 20, a stirrer, 21, a magnetic separation container, 22, an impurity outlet, 23, an impurity box, 24, a magnetic suction pipe, 25, a magnetic separator, 26, an electromagnet, 27, a power supply, 28, an impeller, 29, a product box, 30, nitrogen, 31, a lead, 32, a motor, 33, a product outlet, 34, a sponge iron product, 35, an oscillator, 36 and impurities.
Detailed description of the preferred embodiments
The invention is further described below with reference to the accompanying drawings:
fig. 1 shows the whole process of low-carbon sponge iron refining, wherein the chemical substances used for the low-carbon sponge iron refining are strictly selected, the iron ore powder can be magnetite powder or hematite powder, the reducing agent can be common bituminous coal powder or anthracite powder, the flux lime powder can be common lime or dolomite lime, and the moisture content ratio needs to be controlled.
The used raw materials are respectively ground finely, sieved and repeatedly circulated, and the granularity of fine powder of the raw materials is strictly controlled.
And mixing the sieved fine powder according to the optimal proportion, and uniformly stirring.
Preheating the microwave shaft furnace at 300 +/-10 ℃ for 30-40 minutes, then opening a furnace cover, and distributing materials in layers in an even, loose and gapped manner.
When the microwave shaft furnace is used for smelting, the furnace is closed, the temperature, the chemical reduction reaction and the constant temperature heat preservation time limit are strictly controlled, and the requirements cannot be exceeded.
FIGS. 2 and 3 show the whole structure and refining state of a microwave shaft furnace, wherein a furnace body 1 is a refining main body and must be firm and have good strength, a furnace wall 13 and a furnace bottom 7 are made of refractory and high-temperature-resistant materials, a sealing cover 6 is tightly closed, a control base 8 is freely opened and closed, and a microwave generator 3 is regulated and controlled by a microwave regulator 4; the cooling box 10 is a box body for containing a sponge iron product 34, is arranged at the lower part of the discharge hopper 9, is aligned to the cooling box 10 during discharging, is communicated with the nitrogen pipe 12 and the nitrogen source 11, and is filledwith nitrogen during cooling to protect and prevent oxidation.
FIG. 4 is a diagram showing the relationship between the temperature of preheating, temperature raising, constant temperature heat preservation, temperature lowering and cooling of a microwave shaft furnace and the time coordinate, wherein the ordinate is the temperature value, the abscissa is the time value, the temperature is raised from 20 ℃ at normal temperature to 300 +/-10 ℃ during preheating, 30-40 minutes are needed, the temperature is intersected at the point K, the furnace body is closed after distribution and is heated to 1050 ℃ and is intersected at the point D, the temperature is intersected at the point A when the temperature is raised to 1250 ℃, the temperature is kept at the constant temperature for 5-10 minutes, namely an A-B section, then a power supply is turned off, the discharging and temperature lowering are started, the nitrogen protection cooling is carried out to 20 +/-3 ℃.
Fig. 5 shows a dry magnetic separation purification apparatus and a purification flow chart, the cooled sponge iron powder product is fed from a feed hopper 15 and enters a fine grinding machine 16, after fine grinding, is fed into a screen 18, is sieved by a 180-mesh screen, and is fed into a magnetic separation container 21, under the action of a motor 32, a stirrer 20 and an impeller 28, the powder of the sponge iron product 34 circulates in the magnetic separation container 21, and simultaneously a magnetic separator 25 is started, under the attraction of a magnetic field of an electromagnet 26, the sponge iron product 34 is sucked out from a magnetic suction pipe 24 to a product outlet 33, and enters a product box 29, so that low carbon sponge iron is obtained, the impurities 36 which are not sucked out in the magnetic separation container 21 enter a sundry box 23 from an impurity outlet 22, and the magnetic separation apparatus is used coordinately.
Fig. 6 is a graph showing the curves of microwave heating temperature, time and material change, the ordinate is the material temperature, the abscissa is the heating time, and the curves of lime powder change, coal powder change and iron ore powder change are different.
FIG. 7 is a graph showing the curve of the change of the microwave heating temperature and time with the weight of the iron ore powder containing coal, the ordinate is the material temperature, the abscissa is the heating time, when the iron ore powder containing coal is 1 kg, 2 kg and 3 kg, the temperature change curves are different, the less the material is, the faster the temperature rise is, the less the time is required, the more the material is, the slower the temperature rise is, the more the time is required, and the proportion is proportional, thereby controlling the heating time and speed of the microwave shaft furnace.
FIG. 8 is a structural diagram showing the thermal fragmentation of the pumice when reduced by microwave heating at 1250 ℃, which shows metallic iron in white and pumice in light gray, and which is broken to facilitate the reduction of iron oxide.
FIG. 9 is a structural diagram showing the granular structure of the pumice when the conventional heating reduction is 1250 ℃, wherein metallic iron is white and metallic iron is light gray, and the pumice is not broken, which is not favorable for the reduction of iron oxide.
Example 1:
the device comprises a microwave shaft furnace, a cooling box and a magnetic separator, wherein the magnetic separator is in a quasi-working state;
selecting 72.5 kg of iron ore powder, 20 kg of coal powder and 7.5 kg of lime powder according to the combination ratio;
respectively grinding the iron ore powder, the coal powderand the lime powder which are selected according to the proportion, and respectively sieving by using screens of 150 meshes, 80 meshes and 100 meshes;
mixing the fine powder after fine grinding and sieving according to the proportion, and uniformly stirring;
starting a microwave generator 3, a microwave heater 2 and a microwave regulator 4 of the microwave shaft furnace, opening a sealing cover 6 when preheating to 300 ℃, and distributing materials into a furnace chamber 14 in a layered and loose manner through a hopper 5;
the sealing cover 6 is closed, and the furnace chamber 14 is in a fully closed state;
the microwave heater 2, the microwave generator 3 and the microwave regulator 4 regulate and control the temperature to rise to 1050-1250 ℃, and then keep the temperature for 5-10 minutes at constant temperature;
turning off the microwave heater 2, the microwave generator 3 and the microwave regulator 4;
opening the furnace bottom 7 and the control base 8, and feeding the sponge iron product 34 into the cooling box 10 from the discharge hopper 9;
starting a nitrogen source 11 and a nitrogen pipe 12, conveying 30 nitrogen to a cooling box 10, and cooling to 20 +/-3 ℃;
and (3) placing the cooled sponge iron product 34 into dry magnetic separation purification equipment, carrying out fine grinding by a fine grinding machine 16, sieving by a screen 18, carrying out magnetic field attraction by a magnetic separation container 21, a magnetic separator 25 and an electromagnet 26, and sucking the sponge iron product 34 into a product box 29 to obtain the low-carbon sponge iron, wherein impurities 36 enter a sundry box 23 from an impurity outlet 22.

Claims (5)

1. A method for preparing low-carbon sponge iron by using a microwave shaft furnace is characterized by comprising the following steps: the invention is refined by the following chemical substances, and the combination proportion of the chemical substances is as follows:
measured in kilograms and liters
Iron ore powder: 72.5 kg. + -. 7.5 kg
Pulverized coal: 20 kg. + -. 5 kg
Lime powder: 7.5 kg. + -. 2.5 kg
The preparation method of the invention comprises the following steps:
1) selecting raw materials
The iron ore powder, the coal powder and the lime powder required for preparing the low-carbon sponge iron are carefully selected, and the purity is controlled as follows:
iron ore powder: the iron content is more than 65 percent, and the water content is less than 5 percent
Coal powder: the carbon content is more than 75 percent, and the water content is less than 2 percent
Lime powder: contains calcium oxide more than 80% and water content less than 1%
2) Fine grinding of raw materials
And (4) finely grinding the carefully selected iron ore powder, coal powder and lime powder twice in a dry ball mill respectively.
3) Sieving and fineness control
Sieving the finely ground iron ore powder, coal powder and lime powder by using a screen respectively, and controlling the fineness of the fine ground iron ore powder, coal powder and lime powder;
iron ore powder: sieving with 150 mesh sieve to obtain fine powder with particle size of 0.01-0.5mm
Coal powder: sieving with 80 mesh sieve to obtain fine powder with particle size of 0.01-2mm
Lime powder: sieving with 100 mesh sieve to obtain fine powder with particle size of 0.01-1mm
4) Mixing, blending and mixing
Preparing raw materials of the sieved iron ore powder, the coal powder and the lime powder according to a combination ratio, and mixing in a special container.
5) Stirring the mixture
And stirring the mixed raw material fine powder in a special stirrer repeatedly and uniformly.
6) Microwave shaft furnace preheating
Preheating a microwave shaft furnace used for smelting at the preheating temperature of 300 +/-10 ℃ for 30-40 minutes.
7) Layered fabric
The fine powder of the raw materials which are mixed and stirred evenly is put into a microwave shaft furnace in layers, and the materials are distributed evenly and loosely with gaps according to the structural volume of the microwave shaft furnace.
8) Microwave shaft furnace smelting
The closed microwave shaft furnace is provided with each part in a quasi-working state;
starting a microwave generator, a microwave regulator and a microwave heater, wherein the power of the microwave generator is 25 kilowatts +/-0.5 kilowatts, and the frequency is 2450 megahertz;
the temperature of the microwave shaft furnace is increased from 300 ℃ to 1050 ℃ to 1250 ℃, and the temperature is kept constant for 5 to 10 minutes;
uniformly mixing iron ore powder, coal powder and lime powder, and absorbing heat generated by microwaves in a closed microwave shaft furnace to perform carbon-heat self-reduction to generate solid sponge iron;
in the smelting process of the closed high-temperature microwave shaft furnace, a chemical reaction is generated, and the chemical reaction formula is as follows:
in the formula:
Fe3O4: magnetite powder
5CHmOn: pulverized coal
CaO: lime powder
H2O: water (W)
FeS: iron sulfide
4 Fe: metallic iron
And (2) CaS: calcium sulfide
5 CO: carbon monoxide
5H2mOn: hydroxide compound
9) Cooling under nitrogen protection
After smelting, placing the solid sponge iron in a special cooling box, continuously inputting nitrogen into the cooling box, naturally cooling under the protection of the nitrogen, cooling from 1250 ℃ to 20 +/-3 ℃ for 12 hours, and preventing oxygen from entering.
10) Magnetic separation and purification
Purifying the prepared sponge iron by using special dry magnetic separation equipment, and shaving off impurities in the sponge iron;
finely grinding the sponge iron into powder, sieving the powder by using a 180-mesh sieve, and repeatedly carrying out fine grinding and sieving to ensure that the powder particles are uniform and refined;
placing the powdery sponge iron obtained by fine grinding and sieving in a dry type permanent magnetic separator, and carrying out magnetic separation under a high-intensity magnetic field with the magnetic field intensity of 1.5-2 ten thousand gausses.
11) Detection, comparison and analysis
And (3) detecting, testing, analyzing and comparing the low-carbon sponge iron obtained after magnetic separation and purification, detecting the components, purity, impurities, luster and morphology of the low-carbon sponge iron, and analyzing and detecting the low-carbon sponge iron item by item.
12) And store it
The low-carbon sponge iron powder qualified in smelting detection needs to be stored in a dry and clean environment by a special container, the storage temperature is 20 +/-3 ℃, and the low-carbon sponge iron powder needs to be waterproof, moistureproof, oxidation-resistant and acid-base corrosion-resistant.
2. The method for preparing the low-carbon sponge iron by using the microwave shaft furnace as claimed in claim 1, wherein the method comprises the following steps: the microwave shaft furnace mainly structurally comprises: the device comprises a furnace body, a feeding hopper, a microwave generator, a microwave regulator, a microwave heater, a discharging hopper and a cooling box; the microwave shaft furnace body (1) is externally provided with a microwave heater (2), the microwave heater (2) is symmetrically provided with a microwave generator (3) and a microwave regulator (4) at the left side and the right side, and the middle parts of the microwave heater are connected by a lead (31); the upper part of the furnace body (1) is provided with a sealing cover (6), and the upper part of the sealing cover (6) is provided with a feeding hopper (5); the lower part of the furnace body (1) is a furnace bottom (7), the bottom of the furnace body (1) is a control base (8), the lower part of the control base (8) is a discharge hopper (9), the lower part of the discharge hopper (9) is aligned to a cooling tank (10), the right side part of the cooling tank (10) is connected with a nitrogen pipe (12), and the nitrogen pipe (12) is connected with a nitrogen source (11); the furnace body (1) is internally provided with a furnace wall (13), a furnace chamber (14) is arranged in the furnace wall (13), and the furnace chamber (14) is communicated with the charging hopper (5), the sealing cover (6), the furnace bottom (7), the control base (8) and the discharging hopper (9).
3. The method for preparing the low-carbon sponge iron by using the microwave shaft furnace as claimed in claim 1, wherein the method comprises the following steps: the preheating temperature of the microwave shaft furnace is 300 +/-10 ℃, the smelting temperature is 1050 ℃ -1250 ℃, the constant temperature heat preservation time is 5-10 minutes, the power of a microwave generator is 25 kilowatts +/-0.5 kilowatts, the frequency is 2450 megahertz, and the microwave generation time is 60 minutes +/-20 minutes.
4. The method for preparing the low-carbon sponge iron by using the microwave shaft furnace as claimed in claim 1, wherein the method comprises the following steps: and the nitrogen protection cooling is carried out, natural cooling is carried out in a cooling box (10), nitrogen (30) is continuously filled into the cooling box (10) through a nitrogen source (11) and a nitrogen pipe (12), the natural cooling is carried out to 20 +/-3 ℃, and the cooling and nitrogen filling time is 12 hours.
5. The method for preparing the low-carbon sponge iron by using the microwave shaft furnace as claimed in claim 1, wherein the method comprises the following steps: the purification of the low-carbon sponge iron is carried out on special dry magnetic separation equipment, the upper part of the magnetic separation equipment is provided with a feed hopper (15), the feed hopper (15) is communicated with a fine grinding machine (16), the fine grinding machine (16) is communicated with a feed delivery pipe (17), the feed delivery pipe (17) is communicated with a screen (18), and an oscillator (35) is arranged in the screen (18); the screen (18) is communicated with the material conveying pipe (19), the material conveying pipe (19) is communicated with the magnetic separation container (21), a motor (32), a stirrer (20) and an impeller (28) are arranged in the magnetic separation container (21), the magnetic separation container (21) is communicated with the impurity outlet (22), and the impurity outlet (22) is communicated with the impurity box (23); the right side of the magnetic separation container (21) is communicated with a magnetic suction pipe (24), the right side of the magnetic suction pipe (24) is communicated with a magnetic separator (25), an electromagnet (26) is arranged in the magnetic separator (25), the right side of the electromagnet (26) is connected with a power supply (27), the lower part of the magnetic separator (25) is communicated with a product outlet (33), the product outlet (33) is communicated with a product box (29), and a sponge iron product (34) is stored in the product box (29); the sponge iron product (34) enters a product box (29) after being magnetically separated by a magnetic separator (25), and impurities (36) enter a sundry box (23) through an impurity outlet (22) in a magnetic separation container (21).
CNB2005100125084A 2005-05-10 2005-05-10 Method of manufacturing low carbon sponge iron using microwave vertical furnace Expired - Fee Related CN100398669C (en)

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CN100357457C (en) * 2006-04-04 2007-12-26 太原理工大学 Metal ferrochromium preparing method by computer-controlled double microwave ovens
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WO2010115349A1 (en) * 2009-04-10 2010-10-14 中煤第三建设(集团)有限责任公司 Asphalt concrete pavement containing wave absorbing material and maintenance process thereof
WO2012130091A1 (en) * 2011-03-25 2012-10-04 朗威资源有限公司 Iron ore reducing agent, iron ore mixture, and method for reducing iron ore
CN102424875A (en) * 2011-12-31 2012-04-25 湖南有色金属研究院 Method for preparing sponge iron from sulfate cinder
CN102839250B (en) * 2012-09-28 2014-07-30 昆明理工大学 Method for collecting high-quality coal gas in process of producing reduced iron powder by means of microwave heating
CN102839250A (en) * 2012-09-28 2012-12-26 昆明理工大学 Method for collecting high-quality coal gas in process of producing reduced iron powder by means of microwave heating
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CN103131815A (en) * 2013-03-19 2013-06-05 李学文 Technique for producing spongy iron and nickel iron by microwave high-temperature continuous reduction
CN103131815B (en) * 2013-03-19 2014-10-01 李学文 Technique for producing spongy iron and nickel iron by microwave high-temperature continuous reduction
CN104988268A (en) * 2015-07-29 2015-10-21 安徽工业大学 Electromagnetic heating carbon-bearing pellet continuous direct steelmaking device
CN104988267A (en) * 2015-07-29 2015-10-21 安徽工业大学 Electromagnetic heating carbon-bearing pellet continuous direct steelmaking method
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CN106148677A (en) * 2016-08-02 2016-11-23 西安科技大学 A kind of microwave-assisted selects the method for metalliferous mineral
CN106244755A (en) * 2016-08-19 2016-12-21 环境保护部华南环境科学研究所 A kind of device for producing sponge iron
CN106244755B (en) * 2016-08-19 2018-06-08 环境保护部华南环境科学研究所 A kind of device for producing sponge iron
CN107779536A (en) * 2016-08-31 2018-03-09 中冶长天国际工程有限责任公司 One kind direct-reduction iron production method and device
CN107779536B (en) * 2016-08-31 2020-03-17 中冶长天国际工程有限责任公司 Method and device for producing direct reduced iron
CN108277341A (en) * 2017-12-15 2018-07-13 金川集团股份有限公司 A kind of sponge nickel and its method of preparation
CN109706313A (en) * 2019-01-10 2019-05-03 鞍钢股份有限公司 Method for improving water loss of microwave preheated sintering mixture
CN109706313B (en) * 2019-01-10 2020-06-23 鞍钢股份有限公司 Method for improving water loss of microwave preheated sintering mixture
CN113403440A (en) * 2021-06-11 2021-09-17 张振逵 Production process and equipment for virus-free sponge iron hydrogen carbon steel industrial chain
CN113265507A (en) * 2021-06-28 2021-08-17 王恩礼 Oxygen-free reduction process for iron oxide ore and closed reduction converter thereof

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