CN115613080A - Method and system for preparing molten iron by gas pre-reduction-electrolysis final reduction of iron ore - Google Patents
Method and system for preparing molten iron by gas pre-reduction-electrolysis final reduction of iron ore Download PDFInfo
- Publication number
- CN115613080A CN115613080A CN202210711484.5A CN202210711484A CN115613080A CN 115613080 A CN115613080 A CN 115613080A CN 202210711484 A CN202210711484 A CN 202210711484A CN 115613080 A CN115613080 A CN 115613080A
- Authority
- CN
- China
- Prior art keywords
- iron
- reduction
- oxide
- electrolysis
- furnace
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
- C25C3/34—Electrolytic production, recovery or refining of metals by electrolysis of melts of metals not provided for in groups C25C3/02 - C25C3/32
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B5/00—General methods of reducing to metals
- C22B5/02—Dry methods smelting of sulfides or formation of mattes
- C22B5/12—Dry methods smelting of sulfides or formation of mattes by gases
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
- C25C7/06—Operating or servicing
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/10—Reduction of greenhouse gas [GHG] emissions
- Y02P10/122—Reduction of greenhouse gas [GHG] emissions by capturing or storing CO2
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Manufacture And Refinement Of Metals (AREA)
Abstract
The invention provides a method and a system for preparing molten iron by gas pre-reduction-electrolysis final reduction of iron ore, comprising the following steps: s1: reducing ferric oxide in the pre-reduced raw material into ferrous oxide by reducing gas; s2: taking metallic iron as a cathode; s3: taking the molten mixed oxide as a supporting electrolyte and the pre-reduced ferrous oxide as an electrolytic raw material, raising the temperature to enable the molten mixed oxide and the ferrous oxide to be in a molten state, obtaining an oxide electrolyte and placing the oxide electrolyte above a cathode; s4: putting the inert anode downwards and immersing the inert anode into an oxide electrolyte, and reducing the ferrous oxide into liquid iron by adopting constant current electrolysis; s5: monitoring the content of ferrous oxide in the oxide electrolyte according to the cell pressure and the precipitation condition of the anode gas in the electrolysis process, and supplementing the ferrous oxide according to the monitoring result; s6: after electrolysis is carried out for a period of time, cathode molten iron is collected from an iron outlet at the bottom of the electrolytic furnace, so that the cathode molten iron is maintained within a certain height range, and continuous electrolysis is ensured.
Description
[ technical field ] A method for producing a semiconductor device
The invention relates to the technical field of ferrous metallurgy, in particular to a method and a system for preparing molten iron by reducing iron ore through gas prereduction-electrolysis final reduction.
[ background of the invention ]
As a fundamental product of national economyThe steel industry is ballast stone developed by the economic society of China and is a material guarantee for national defense construction of the people. However, the steel industry in China faces a significant problem: the production process taking the long flow of the blast furnace-converter as the leading factor has high fossil energy consumption and large carbon emission. Currently, the energy consumption of the steel industry in China accounts for about 15 percent of the total energy consumption of the whole country, and CO 2 The emission amount accounts for 12 to 16 percent of the national emission, and is CO in China 2 One of the main sources of emissions, and the steel industry is about 70% energy consumption and 80% CO 2 The discharge comes from the ironmaking system. Aiming at the problems of serious pollution, high carbon emission and the like faced by the traditional blast furnace ironmaking, various new low-carbon ironmaking technologies are proposed at home and abroad in recent years. In the aspect of blast furnace low-carbon iron making, a technical route of high-reduction potential gas injection is mainly proposed at home and abroad. The japanese COURSE50 project revolved around blast furnace carbon reduction and developed a hydrogen reduction iron making process that partially uses hydrogen as a reducing agent instead of coke. In the aspect of a new low-carbon technology of a blast furnace, a furnace top gas circulation process (TGR-BF) is researched in the EU ULCOS project. Relevant work of blowing Ou metallurgical furnace decarburization coal gas into Bao steel oxygen blast furnace in China, and 250m of boosting air injection 3 And/t, saving 70kg of coke relative to a benchmark ton of iron under the condition of oxygen enrichment of 50%. In the aspect of shaft furnace direct reduction, a novel gas-based hydrogen-rich/total hydrogen shaft furnace process is rapidly developed. The HYBRIT project initiated by SSAB company in Sweden, the SALCOS project initiated by Saertz Ji Tegang iron company in Germany and the H2FUTURE project initiated by the Otto union all adopt the idea that green hydrogen is utilized to reduce iron ore so as to achieve the purpose of carbon emission reduction. China emphatically develops a coke oven gas modification-shaft furnace direct reduction process aiming at the characteristics of self resources. The CSDRI process of Beijing university of science and technology participating in research and development has been promoted in Shanxi to a hydrogen shaft furnace project producing 30 ten thousand tons of Direct Reduced Iron (DRI) annually, dry-reformed coke oven gas is taken as reducing gas, and the aim is to make CO into 2 The emission is reduced by 28%. The current research and development of new low-carbon iron-making processes mostly mainly use hydrogen-rich metallurgy, and the problems of low production efficiency and energy efficiency and the like exist in total hydrogen metallurgy. From the perspective of the whole iron-making process, the current low-carbon iron-making technology still has a larger promotion space.
The electrochemical metallurgy is a green clean metalThe extraction technology is a main production method for large amount of nonferrous metals (such as aluminium, copper, etc.), alkali/alkaline earth metals and rare earth metals, etc. In view of the aluminum Electrolysis process, the Sadoway in massachusetts has developed direct Electrolysis of metallic iron (MOE) from Molten metal oxides. The process is to dissolve Fe 2 O 3 The molten oxide of (2) is an electrolyte, and can be directly electrolyzed to prepare liquid metal iron. In addition, based on the development and application of the inert anode, the molten salt electrochemical metallurgy can realize the carbon-free emission of the process. But currently as Fe 2 O 3 The current efficiency of the MOE ironmaking process as a raw material still needs to be improved.
Accordingly, there is a need to develop a method and system for manufacturing molten iron by gas pre-reduction-electrolysis of final reduced iron ore that can overcome the disadvantages of the related art and solve or alleviate one or more of the above-mentioned problems.
[ summary of the invention ]
In view of the above, the invention provides a method and a system for preparing molten iron by gas pre-reduction-electrolysis final reduction of iron ore, which can greatly reduce the problem of carbon emission in the iron-making process compared with the traditional metallurgy process of iron and steel; meanwhile, the method has the advantages of simple operation, high iron extraction efficiency, easy large-scale production and the like, and is an effective technical route for low-carbon iron making.
In one aspect, the present invention provides a method for manufacturing molten iron by gas pre-reduction-electrolysis of final reduced iron ore, the method comprising the steps of:
s1: reducing ferric oxide in the pre-reduced raw material into ferrous oxide by reducing gas;
s2: taking metallic iron as a cathode;
s3: taking the molten mixed oxide as a supporting electrolyte, taking the pre-reduced ferrous oxide as an electrolysis raw material, raising the temperature to enable the molten mixed oxide and the ferrous oxide to be in a molten state, obtaining an oxide electrolyte and placing the oxide electrolyte above a cathode;
s4: putting the inert anode downwards and immersing the inert anode into an oxide electrolyte, and reducing the ferrous oxide into liquid iron by adopting constant current electrolysis;
s5: monitoring the content of ferrous oxide in the oxide electrolyte according to the cell pressure and the precipitation condition of the anode gas in the electrolysis process, and supplementing the ferrous oxide according to the monitoring result;
s6: after electrolysis for a period of time, cathode molten iron is collected from an iron outlet at the bottom of the electrolytic furnace, so that the cathode molten iron is maintained within a certain height range, and continuous electrolysis is ensured.
The above aspects and any possible implementations further provide an implementation where the reducing gas in the S1 pre-reduction subsystem includes, but is not limited to, H 2 CO, hydrogen-rich or CO-rich gas, the temperature of the introduced reducing gas is more than 570 ℃.
In accordance with the above-described aspects and any possible implementation manner, there is further provided an implementation manner, wherein the operating temperature in the S1 pre-reduction subsystem is 600-1200 ℃, the reduction time is 0.2-3h, and the content of unreduced iron trioxide in the pre-reduced raw material is less than 5%.
The above aspects and any possible implementation manners further provide an implementation manner, wherein the pre-reduced material in the S1 pre-reduction sub-system is iron ore or fine ore, the iron grade of the iron ore or fine ore is more than 40%, when the pre-reduced material is iron ore, the operating temperature in the S1 pre-reduction sub-system is 800-1200 ℃, and when the pre-reduced material is fine ore, the operating temperature in the S1 pre-reduction sub-system is 600-1000 ℃.
The above aspects and any possible implementation manners further provide an implementation manner, wherein the electrolytic furnace in the S2 electrolysis iron-making subsystem is an existing direct current electric arc furnace or a metallurgical furnace which can work at 1600-2000 ℃ and can realize inert gas protection.
The above aspects and any possible implementation manners further provide an implementation manner, in S2, the iron is molten iron obtained after blast furnace smelting or iron blocks or iron powder at normal temperature, wherein a melting temperature of the molten iron is greater than 1500 ℃, and a height of the molten iron blocks or iron powder at normal temperature is between 5 and 20 cm.
The above aspect and any possible implementation manner further provide an implementation manner, wherein the oxygen in S3Electrolyte of compounds is CaO, mgO, siO 2 、Al 2 O 3 、TiO 2 、Na 2 O、Li 2 O three or more mixed oxides plus FeO as a reactant, which is in a solid state at room temperature, has a melting point of 1000 to 1700 ℃ and a height of about 3 to 30cm after melting.
In accordance with the above aspects and any possible implementation manner, there is further provided an implementation manner, in S4, the inert anode is a corrosion-resistant material prepared from a chromium-based superalloy or a metal boride ceramic, and the cathode current density used in the constant current electrolysis is 0.01-3A/cm 2 The current density of the anode is 0.01-5A/cm 2 The bath voltage is 0.5-10.0V, and the electrolysis temperature is 1200-1700 ℃.
The above-mentioned aspect and any possible implementation manner further provide an implementation manner, wherein the ferrous oxide is supplemented in S5 according to the monitoring result, specifically, the ferrous oxide content in the oxide electrolyte is maintained between 1 and 20 wt%.
The above aspects and any possible implementations further provide a system for manufacturing molten iron by gas pre-reduction-electrolysis of final reduced iron ore for the method for manufacturing molten iron, the system for manufacturing molten iron including:
the system comprises a pre-reduction subsystem and an electrolytic iron-making subsystem, wherein the pre-reduction subsystem is used for reducing ferric oxide in a pre-reduction raw material into ferrous oxide, and the electrolytic iron-making subsystem is used for electrolyzing the ferrous oxide in the pre-reduction subsystem to output molten iron;
the pre-reduction subsystem comprises:
the device comprises a pre-reduction furnace, a pre-reduction feed port is arranged at the top of the pre-reduction furnace, a reduction area is arranged in the middle of the pre-reduction furnace, a pre-reduction discharge port is arranged at the bottom of the pre-reduction furnace, the pre-reduction feed port is used for feeding pre-reduction raw materials and reduction gas, the reduction area is used for pre-reduction work, and the pre-reduction discharge port is used for outputting ferrous oxide;
the conveying device is used for conveying the ferrous oxide to the electrolytic iron-making subsystem;
the electrolytic iron making subsystem comprises:
the electrolytic furnace is provided with a liquid iron outlet at the bottom, the metal iron is arranged at the bottom of the electrolytic furnace before the reaction starts, and the oxide electrolyte is arranged above the metal iron; the top of the electrolytic furnace is provided with an electrolytic raw material inlet and a gas outlet, the electrolytic raw material inlet is connected with the conveying device, and the gas outlet is used for acquiring the cell pressure and the anode gas separation condition;
and one end of the inert anode is arranged outside the electrolytic furnace, and the other end of the inert anode is arranged in the oxide electrolyte in the electrolytic cell.
Compared with the prior art, the invention can obtain the following technical effects:
1. the liquid iron is prepared by reducing the iron ore with the reducing gas and green electrons, so that the consumption of coke is greatly reduced compared with the traditional process, and the carbon emission in the smelting process is reduced;
2. the liquid iron is prepared by taking the ferrous oxide as a raw material, so that the current efficiency is high, the iron purity is high, the energy consumption can be effectively reduced, and the continuous production of the liquid iron is realized;
of course, it is not necessary for any one product to practice the invention to achieve all of the above-described technical results simultaneously.
[ description of the drawings ]
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described 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 shows a reducing gas (CO or H) provided in accordance with an embodiment of the present invention 2 ) A pre-reduced iron ore reaction equilibrium phase diagram;
FIG. 2 is a schematic view illustrating a process for manufacturing molten iron by gas pre-reduction-electrolysis of final reduced iron ore according to an embodiment of the present invention;
FIG. 3 is a cathodic iron deposition product after electrolysis of molten oxide provided in accordance with one embodiment of the present invention.
[ detailed description ] embodiments
For better understanding of the technical solutions of the present invention, the following detailed descriptions of the embodiments of the present invention are provided with reference to the accompanying drawings.
It should be understood that the described embodiments are only some embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without inventive exercise, are within the scope of protection of the present invention.
The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
The present invention provides a method for manufacturing molten iron by gas pre-reduction-electrolysis of final reduced iron ore, the method comprising the steps of:
s1: introducing reducing gas into the pre-reduction subsystem to reduce ferric oxide in the pre-reduction raw material into ferrous oxide;
s2: in the electrolytic iron-making subsystem, metallic iron is placed at the bottom of an electrolytic furnace and is used as a cathode in the electrolytic process;
s3: taking the molten mixed oxide as a supporting electrolyte, taking the pre-reduced ferrous oxide as an electrolysis raw material, and raising the temperature to enable the molten mixed oxide and the ferrous oxide to be in a molten state to obtain an oxide electrolyte;
s4: putting the inert anode downwards and immersing the inert anode into an oxide electrolyte, and reducing the ferrous oxide into liquid iron by adopting constant current electrolysis;
s5: monitoring the content of ferrous oxide in the oxide electrolyte according to the cell pressure and the precipitation condition of the anode gas in the electrolysis process, and supplementing the ferrous oxide according to the monitoring result;
s6: after electrolysis is carried out for a period of time, cathode molten iron is collected from an iron outlet at the bottom of the electrolytic furnace, so that the cathode molten iron is maintained within a certain height range, and continuous electrolysis is ensured.
The reducing gas in the S1 pre-reduction subsystem includes but is not limited to H 2 CO, hydrogen-rich or CO-rich gas such as coke oven gas and the like, and the temperature of the introduced reducing gas is more than 570 ℃.
The working temperature in the S1 pre-reduction subsystem is 600-1200 ℃, the reduction time is 0.2-3h, and the content of unreduced ferric oxide in the pre-reduction raw material is less than 5%.
The pre-reduction raw material in the S1 pre-reduction subsystem is iron ore or fine ore, the iron grade of the iron ore or the fine ore is more than 40%, when the pre-reduction raw material is the iron ore, the working temperature in the S1 pre-reduction subsystem is 800-1200 ℃, and when the pre-reduction raw material is the fine ore, the working temperature in the S1 pre-reduction subsystem is 600-1000 ℃.
In the S1, ferrous oxide is obtained after reduction for a certain time according to the components of the reducing gas, the ferrous oxide can be rapidly fused with other oxides to form electrolyte, the influence on the physicochemical property and the stability of the oxide electrolyte is small, and the current efficiency is higher than that of electrolysis directly using iron ore; the equilibrium state of the reduction reaction is carried out as shown in figure 1, namely a fork curve, and the reaction temperature range is determined by the components of the reducing gas;
in the invention, when the raw material is selected, because the iron ore can be directly electrolyzed theoretically, but the problem that the iron ore is difficult to melt, and the physicochemical property and the stability of the oxide electrolyte are influenced, so that the current efficiency is low exists, therefore, the ferrous oxide is directly used in the raw material selection, can be well melted with other oxides, has little influence on the physicochemical stability of the oxide electrolyte, and has higher current efficiency than the direct electrolysis of the iron ore. Because ferrous iron is used as a raw material, the reduced ferrous oxide temperature is 700-800 ℃, and high-temperature resistant transmission equipment is required to transport the ferrous oxide to an electrolytic iron making subsystem, high-temperature resistant steel or alloy is used in the invention.
The reduction reaction involved in the pre-reduction shaft furnace comprises the following steps:
CO+3Fe 2 O 3 ＝2Fe 3 O 4 +CO 2 ；
CO+Fe 3 O 4 ＝3FeO+CO 2 ；
H 2 +3Fe 2 O 3 ＝2Fe 3 O 4 +H 2 O；
H 2 +Fe 3 O 4 ＝3FeO+H 2 O；
the electrolytic furnace in the S2 electrolysis iron-making subsystem is an existing direct current electric arc furnace or a metallurgical furnace which can work between 1600 ℃ and 2000 ℃ and can realize inert gas protection.
And the iron in the S2 is molten iron smelted by a blast furnace or iron blocks or iron powder at normal temperature, wherein the melting temperature of the molten iron is more than 1500 ℃, and the height of the molten iron blocks or iron powder at normal temperature is between 5 and 20 cm.
The oxide electrolyte in S3 is CaO, mgO, siO 2 、Al 2 O 3 、TiO 2 、Na 2 O、Li 2 O three or more mixed oxides as supporting electrolyte and FeO as reactant, which is solid at room temperature, has a melting point of 1000-1700 deg.C, and a height of 3-30cm after melting. Because the oxide electrolyte contains the supporting electrolyte, the supporting electrolyte can adjust the physical and chemical properties of the whole melt, such as conductivity, viscosity and the like, and the smooth operation of the electrolytic process is ensured. Therefore, the oxide composition or content directly determines the physical and chemical properties of the electrolyte, such as conductivity, viscosity, etc., and thus can be adjusted according to the electrolysis requirement.
The inert anode in S4 is a corrosion-resistant material prepared from chromium-based superalloy or metal boride ceramic, and the cathode current density adopted by constant current electrolysis is 0.01-3A/cm 2 The anode current density is 0.01-5A/cm 2 The bath voltage is 0.5-10.0V, and the electrolysis temperature is 1200-1700 ℃. The product gas after using an inert anode is oxygen, which can be collected and reused.
The inert anode is selected in the invention because the finally generated gas is oxygen, can be collected and utilized and has no pollution; if a carbon anode is used instead of an inert anode, the gas generated is CO 2 Or CO, there is a problem with carbon emissions.
Supplementing ferrous oxide in the S5 according to the monitoring result, namely keeping the content of the ferrous oxide in the oxide electrolyte between 1 and 20 weight percent;
the electrochemical reaction mechanism involved in the electrochemical process is as follows, wherein an inert electrode is taken as an anode, liquid iron is taken as a cathode, and an oxide is taken as a supporting electrolyte:
2O 2- -4e＝O 2 (g)；
Fe 2+ +2e＝Fe(l)。
as shown in fig. 2, the present invention also provides a system for manufacturing molten iron by gas pre-reduction-electrolysis of final reduced iron ore for the method for manufacturing molten iron, the system comprising:
the system comprises a pre-reduction subsystem and an electrolytic iron-making subsystem, wherein the pre-reduction subsystem is used for reducing ferric oxide in a pre-reduction raw material into ferrous oxide, and the electrolytic iron-making subsystem is used for electrolyzing the ferrous oxide in the pre-reduction subsystem to output molten iron;
the pre-reduction subsystem comprises:
the device comprises a pre-reduction furnace, a pre-reduction feed port is arranged at the top of the pre-reduction furnace, a reduction area is arranged in the middle of the pre-reduction furnace, a pre-reduction discharge port is arranged at the bottom of the pre-reduction furnace, the pre-reduction feed port is used for feeding pre-reduction raw materials and reduction gas, the reduction area is used for pre-reduction work, and the pre-reduction discharge port is used for outputting ferrous oxide;
the conveying device is used for conveying ferrous oxide to the electrolytic iron-making subsystem, and the conveying device is made of high-temperature-resistant steel or alloy;
the electrolytic iron making subsystem comprises:
the electrolytic furnace is provided with a liquid iron outlet at the bottom, the metal iron is arranged at the bottom of the electrolytic furnace before the reaction starts, and the oxide electrolyte is arranged above the metal iron; the top of the electrolytic furnace is provided with an electrolytic raw material inlet and a gas outlet, the electrolytic raw material inlet is connected with the conveying device, and the gas outlet is used for acquiring the cell pressure and the anode gas separation condition;
and one end of the inert anode is arranged outside the electrolytic furnace, and the other end of the inert anode is arranged in the oxide electrolyte in the electrolytic cell.
The reaction mechanism of the invention is as follows:
reducing the iron ore into ferrous oxide by reducing gas in a pre-reduction furnace, wherein the reducing temperature is 600-1200 ℃; ferrous oxide is taken as a raw material and added into a fused oxide electrolyte system, and the melting point range of the electrolyte is between 1000 and 1700 ℃; carrying out constant current electrolysis by taking an inert electrode as an anode and liquid iron as a cathode, wherein the electrolysis temperature is 1200-1700 ℃; after electrolyzing for a certain time, collecting the liquid iron obtained at the cathode at an iron outlet, and continuously generating O at the anode 2 And ferrous oxide is continuously added in the electrolytic process to ensure that the iron deposition process is continuously carried out. The invention adopts two-stage reduction to prepare liquid iron, thereby not only avoiding high carbon emission in the traditional steel smelting process, but also improving the low current efficiency of MOE deposited iron when ferric oxide is used as a raw material; an inert anode is adopted in the electrolysis process, no carbon emission is generated, and the final product is high-purity liquid iron; the invention can effectively reduce the carbon emission in the steel smelting process.
Example 1:
iron ore is used as a raw material and is added from the top of a pre-reduction furnace. Coke oven gas of 900 ℃ is introduced into the circumference of the pre-reduction furnace, and the inlet pressure can be 2 atmospheric pressures. After 35min reduction, the reducing gas in the pre-reduction furnace can reduce the iron ore into furnace charge with high ferrous oxide content, which is used as raw material and conveyed to the inlet of the electrolysis device through a conveyor belt or a discharger. The bottom of the electrolyzer was fitted with a high-purity iron plate, previously filled with an initial oxide electrolyte (19.1 wt% CaO-23.6wt% MgO-45.6 wt%) 2 -11.7wt％Al 2 O 3 ). Electrifying the electrolyzer, heating to 1600 deg.C to melt oxide electrolyte and iron plate into liquid, dissolving furnace charge with high ferrous oxide content in the electrolyte system, and anode adopting Cr/Fe/TiB 2 Cermet material, starting electrolysis, cathode current density of 0.2A/cm 2 . In the electrolysis process, furnace burden with high ferrous oxide content can be continuously or intermittently added, and when the slag amount and the iron amount in the electrolysis device reach certain heights, most of liquid slag iron is discharged to a corresponding container through a tap hole for subsequent use, namely intermittent slag iron discharge.
Example 2:
iron ore is used as a raw material and is added from the top of a pre-reduction furnace. H with the temperature of 1000 ℃ is introduced into the circumference of the pre-reduction furnace 2 And CO mixture (volume fraction ratio 3:1), the inlet pressure can be 2.5 atmospheres. After reduction for 20min, the reducing gas in the pre-reduction furnace can reduce the iron ore concentrate into furnace charge with high ferrous oxide content, and the furnace charge is used as a raw material and conveyed to the inlet of the electrolysis device through a conveyor belt or a discharger. The bottom of the electrolyzer was charged with high purity iron plate, pre-charged with initial oxide electrolyte (57.9wt% CaO-10.3wt% MgO-31.8wt% Al% 2 O 3 ). Electrifying the electrolysis device, heating to 1500 deg.C to melt oxide electrolyte and iron plate into liquid, dissolving furnace charge with high ferrous oxide content into electrolyte system, and adopting Cr/Fe/TiB as anode 2 Cermet material, starting electrolysis with a cathodic current density of 0.5A/cm 2 . In the electrolysis process, furnace burden with high ferrous oxide content can be continuously or intermittently added, and when the slag amount and the iron amount in the electrolysis device reach certain heights, most of liquid slag iron is discharged to a corresponding container through a tap hole for subsequent use, namely intermittent slag iron.
Example 3:
iron ore is used as a raw material and is added from the top of a pre-reduction furnace. H with the temperature of 950 ℃ is introduced into the circumference of the pre-reduction furnace 2 And CO mixture (volume fraction ratio 1:1), the inlet pressure can be 2.5 atmospheres. After reduction for 25min, the reducing gas in the pre-reduction furnace can reduce the iron ore concentrate into furnace charge with high ferrous oxide content, and the furnace charge is used as a raw material and conveyed to the inlet of the electrolysis device through a conveying belt or a discharger. The bottom of the electrolyzer was fitted with a high purity iron plate, pre-charged with initial oxide electrolyte (50wt% CaO-10.3wt%, mgO-39.7wt%) 2 O 3 ). Electrifying the electrolysis device, heating to 1600 deg.C to melt oxide electrolyte and iron plate into liquid, dissolving furnace charge with high ferrous oxide content into electrolyte system, and adopting Cr/Fe/TiB as anode 2 Cermet material, starting electrolysis with a cathodic current density of 1A/cm 2 . Charging materials with high ferrous oxide content can be continuously or intermittently added in the electrolysis process, and when the electrolysis is carried outAfter the slag amount and the iron amount in the device reach a certain height, most of liquid slag iron is discharged to a corresponding container through a tapping hole for subsequent use, namely intermittent slag iron discharge.
Example 4:
iron ore powder is used as a raw material and is added from the top of a pre-reduction furnace. H with the temperature of 800 ℃ is introduced into the circumference of the pre-reduction furnace 2 And CO mixture (volume fraction ratio 1:1), the inlet pressure can be 2.5 atmospheres. After 40min reduction, the reducing gas in the pre-reduction furnace can reduce the iron ore concentrate into furnace charge with high ferrous oxide content, and the furnace charge is used as a raw material and is conveyed to the inlet of the electrolytic device through a conveyor belt or a discharger. The bottom of the electrolyzer was charged with high purity iron plate, pre-charged with initial oxide electrolyte (57.9wt% CaO-10.3wt% MgO-31.8wt% Al% 2 O 3 ). Electrifying the electrolysis device, heating to 1500 deg.C to melt oxide electrolyte and iron plate into liquid, dissolving furnace charge with high ferrous oxide content into electrolyte system, and adopting Cr/Fe/TiB as anode 2 Cermet material, starting electrolysis with a cathodic current density of 1A/cm 2 . In the electrolysis process, furnace burden with high ferrous oxide content can be continuously or intermittently added, and when the slag amount and the iron amount in the electrolysis device reach certain heights, most of liquid slag iron is discharged to a corresponding container through a tap hole for subsequent use, namely intermittent slag iron.
Example 5:
iron ore powder is taken as a raw material and is added from the top of a pre-reduction furnace. H with the temperature of 950 ℃ is introduced into the circumference of the pre-reduction furnace 2 And CO mixture (volume fraction ratio 4:1), the inlet pressure can be 2.5 atmospheres. After 20min of reduction, the reducing gas in the pre-reduction furnace can reduce the iron ore concentrate into furnace charge with high ferrous oxide content, and the furnace charge is used as raw material and is conveyed to the inlet of the electrolytic device through a conveyor belt or a discharger. The bottom of the electrolyzer was fitted with a high-purity iron plate, previously filled with an initial oxide electrolyte (19.1wt% CaO-23.6wt% MgO-45.6 wt%) 2 -11.7 wt％Al 2 O 3 ). Electrifying the electrolysis device, heating to 1600 deg.C to melt oxide electrolyte and iron plate into liquid, dissolving furnace charge with high ferrous oxide content into electrolyte system, and adopting anodeCr/Fe/TiB 2 Cermet material, starting electrolysis with a cathodic current density of 0.2A/cm 2 . In the electrolysis process, furnace burden with high ferrous oxide content can be continuously or intermittently added, and when the slag amount and the iron amount in the electrolysis device reach certain heights, most of liquid slag iron is discharged to a corresponding container through a tap hole for subsequent use, namely intermittent slag iron discharge.
The method and the system for manufacturing molten iron by gas pre-reduction-electrolysis of final reduction iron ore according to the embodiments of the present application are described in detail above. The above description of the embodiments is only for the purpose of helping to understand the method of the present application and its core ideas; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present description should not be construed as a limitation to the present application.
As used in the specification and claims, certain terms are used to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. The description and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, and a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect. The following description of the preferred embodiment is provided to illustrate the general principles of the application and should not be taken as limiting the scope of the application. The protection scope of the present application shall be subject to the definitions of the appended claims.
It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a good or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such good or system. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of additional like elements in a commodity or system comprising the element.
It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" in this document generally indicates that the preceding and following associated objects are in an "or" relationship.
The foregoing description shows and describes several preferred embodiments of the present application, but as aforementioned, it is to be understood that the application is not limited to the forms disclosed herein, and is not to be construed as excluding other embodiments, but rather is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the application as expressed herein, commensurate with the above teachings or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the application, which is to be protected by the claims appended hereto.
Claims (10)
1. A method for manufacturing molten iron by gas pre-reduction-electrolysis of final reduced iron ore, comprising the steps of:
s1: reducing ferric oxide in the pre-reduced raw material into ferrous oxide by reducing gas;
s2: taking metallic iron as a cathode;
s3: taking the molten mixed oxide as a supporting electrolyte, taking the pre-reduced ferrous oxide as an electrolysis raw material, raising the temperature to enable the molten mixed oxide and the ferrous oxide to be in a molten state, obtaining an oxide electrolyte and placing the oxide electrolyte above a cathode;
s4: putting the inert anode downwards and immersing the inert anode into an oxide electrolyte, and reducing the ferrous oxide into liquid iron by adopting constant current electrolysis;
s5: monitoring the content of ferrous oxide in the oxide electrolyte according to the cell pressure and the precipitation condition of the anode gas in the electrolysis process, and supplementing the ferrous oxide according to the monitoring result;
s6: after electrolysis for a period of time, cathode molten iron is collected from an iron outlet at the bottom of the electrolytic furnace, so that the cathode molten iron is maintained within a certain height range, and continuous electrolysis is ensured.
2. The method for manufacturing molten iron according to claim 1, wherein the reducing gas in the S1 pre-reduction sub-system includes but is not limited to H 2 CO, hydrogen-rich or CO-rich gas, and the temperature of the introduced reducing gas is more than 570 ℃.
3. The method for preparing molten iron according to claim 1, wherein the working temperature in the S1 pre-reduction subsystem is 600-1200 ℃, the reduction time is 0.2-3h, and the content of unreduced iron trioxide in the pre-reduction raw material is less than 5%.
4. The method for manufacturing molten iron according to claim 3, wherein the pre-reduced material in the S1 pre-reduction sub-system is iron ore or fine ore, the iron grade of the iron ore or fine ore is greater than 40%, the operating temperature in the S1 pre-reduction sub-system is 800-1200 ℃ when the pre-reduced material is iron ore, and the operating temperature in the S1 pre-reduction sub-system is 600-1000 ℃ when the pre-reduced material is fine ore.
5. The method for manufacturing molten iron according to claim 1, wherein the electrolytic furnace in the S2 electrolysis iron-making subsystem is an existing direct current electric arc furnace or a metallurgical furnace which can work between 1600-2000 ℃ and can realize inert gas protection.
6. The method for manufacturing molten iron according to claim 4, wherein the iron in S2 is molten iron after blast furnace smelting or iron blocks or iron powder at normal temperature, wherein the melting temperature of the molten iron is more than 1500 ℃, and the height of the molten iron blocks or iron powder at normal temperature after melting is between 5 and 20 cm.
7. The method for manufacturing molten iron according to claim 1, wherein the oxide electrolyte in S3 is CaO, mgO, siO 2 、Al 2 O 3 、TiO 2 、Na 2 O、Li 2 O three or more mixed oxides plus FeO as a reactant, which is in a solid state at room temperature, has a melting point of 1000 to 1700 ℃ and a height of about 3 to 30cm after melting.
8. The method for manufacturing molten iron according to claim 1, wherein the inert anode in S4 is a corrosion-resistant material made of a chromium-based superalloy or a metal boride ceramic, and the cathode current density used in the galvanostatic electrolysis is 0.01-3A/cm 2 The current density of the anode is 0.01-5A/cm 2 The bath voltage is 0.5-10.0V, and the electrolysis temperature is 1200-1700 ℃.
9. The method for manufacturing molten iron according to claim 1, wherein the supplementing of the ferrous oxide according to the monitoring result in S5 is performed to maintain a content of the ferrous oxide in the oxide electrolyte between 1 and 20 wt%.
10. A system for manufacturing molten iron by gas pre-reduction-electrolysis of final reduced iron ore for the method for manufacturing molten iron according to any one of claims 1 to 9, wherein the system for manufacturing molten iron comprises:
the system comprises a pre-reduction subsystem and an electrolytic iron-making subsystem, wherein the pre-reduction subsystem is used for reducing ferric oxide in a pre-reduction raw material into ferrous oxide, and the electrolytic iron-making subsystem is used for electrolyzing the ferrous oxide in the pre-reduction subsystem to output molten iron;
the pre-reduction subsystem comprises:
the device comprises a pre-reduction furnace, a pre-reduction feed port is arranged at the top of the pre-reduction furnace, a reduction area is arranged in the middle of the pre-reduction furnace, a pre-reduction discharge port is arranged at the bottom of the pre-reduction furnace, the pre-reduction feed port is used for feeding pre-reduction raw materials and reduction gas, the reduction area is used for pre-reduction work, and the pre-reduction discharge port is used for outputting ferrous oxide;
the conveying device is used for conveying the ferrous oxide to the electrolytic iron-making subsystem;
the electrolytic iron making subsystem comprises:
the electrolytic furnace is provided with a liquid iron outlet at the bottom, the metal iron is arranged at the bottom of the electrolytic furnace before the reaction starts, and the oxide electrolyte is arranged above the metal iron; the top of the electrolytic furnace is provided with an electrolytic raw material inlet and a gas outlet, the electrolytic raw material inlet is connected with the conveying device, and the gas outlet is used for acquiring the cell pressure and the anode gas separation condition;
and one end of the inert anode is arranged outside the electrolytic furnace, and the other end of the inert anode is arranged in the oxide electrolyte in the electrolytic furnace.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210711484.5A CN115613080A (en) | 2022-06-22 | 2022-06-22 | Method and system for preparing molten iron by gas pre-reduction-electrolysis final reduction of iron ore |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210711484.5A CN115613080A (en) | 2022-06-22 | 2022-06-22 | Method and system for preparing molten iron by gas pre-reduction-electrolysis final reduction of iron ore |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115613080A true CN115613080A (en) | 2023-01-17 |
Family
ID=84856548
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210711484.5A Pending CN115613080A (en) | 2022-06-22 | 2022-06-22 | Method and system for preparing molten iron by gas pre-reduction-electrolysis final reduction of iron ore |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115613080A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118326458A (en) * | 2024-06-14 | 2024-07-12 | 包头市明芯新材料有限公司 | Electrolytic tank and rare earth electrolysis device |
-
2022
- 2022-06-22 CN CN202210711484.5A patent/CN115613080A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118326458A (en) * | 2024-06-14 | 2024-07-12 | 包头市明芯新材料有限公司 | Electrolytic tank and rare earth electrolysis device |
| CN118326458B (en) * | 2024-06-14 | 2024-08-16 | 包头市明芯新材料有限公司 | Electrolytic tank and rare earth electrolysis device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1311090C (en) | Bessemer matte production method using nickel sulfide materials | |
| CN103484721B (en) | A kind of method preparing ferro-titanium | |
| CN101665848B (en) | Direct steel making process for iron ore | |
| CN108360023B (en) | Method and device for composite deoxidation alloying of aluminum and magnesium | |
| CN103160864B (en) | The method of ferrocolumbium is prepared in the fused salt electrolysis of a kind of niobium concentrate | |
| CN111411234A (en) | Jet smelting electrothermal reduction furnace and method for smelting zinc-containing material | |
| US20240191382A1 (en) | Method for preparing rare earth alloys | |
| CN103045788A (en) | Reduction steel-making method and reduction steel-marking device | |
| WO2023246367A1 (en) | Antimony-sulfide-containing ore-based molten salt electrolysis continuous production method and apparatus | |
| CN101906646B (en) | Method for preparing iron metal by molten salt electrolysis of iron ore | |
| CN101684507A (en) | Direct steel making technique by reducing iron ore with gas | |
| CN108411065A (en) | Method and device for manganese alloying by using manganese ore | |
| CN115613080A (en) | Method and system for preparing molten iron by gas pre-reduction-electrolysis final reduction of iron ore | |
| CN104694973A (en) | Process for preparing ferrotitanium alloy | |
| CN101899548A (en) | Novel process for scrap steel preheating and premelting and high-efficiency electric furnace steel making | |
| RU2741038C1 (en) | Method and device for melting copper with complex processing of slag | |
| CN106811563B (en) | Method for iron ore reduction iron making by applying electric field | |
| CN103160863B (en) | A kind of method of niobium concentrate molten oxide electrolytic preparation ferrocolumbium | |
| CN113430398B (en) | JCr 98-grade metallic chromium containing vanadium element and preparation method thereof | |
| CN111172409B (en) | Recovery smelting process of tin-containing material | |
| CN110408960B (en) | Method and equipment for continuously preparing high-purity titanium by oxide fusion electrolysis-vacuum rectification | |
| CN112746143A (en) | Process for smelting low-carbon ferroalloy in direct-current electric arc furnace without coke | |
| CN108359769B (en) | Method and device for deoxidizing and alloying silicon oxide-containing material | |
| CN109136588A (en) | A kind of gas-based shaft kiln directly reduced method for producing high titanium slag of ilmenite concentrate | |
| CN118204500B (en) | Low-cost high-purity iron powder and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |