CN117947262A - System and method for low-carbon electrometallurgical of iron ore - Google Patents

System and method for low-carbon electrometallurgical of iron ore Download PDF

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CN117947262A
CN117947262A CN202211412820.2A CN202211412820A CN117947262A CN 117947262 A CN117947262 A CN 117947262A CN 202211412820 A CN202211412820 A CN 202211412820A CN 117947262 A CN117947262 A CN 117947262A
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acidolysis
temperature
pipeline
heat exchange
electrometallurgical
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朱庆山
杨海涛
胡家城
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Institute of Process Engineering of CAS
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    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22BPRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B1/00Preliminary treatment of ores or scrap
    • C22B1/02Roasting processes
    • C22B1/10Roasting processes in fluidised form
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B7/00Hydraulic cements
    • C04B7/24Cements from oil shales, residues or waste other than slag
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21BMANUFACTURE OF IRON OR STEEL
    • C21B15/00Other processes for the manufacture of iron from iron compounds
    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25BELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B1/00Electrolytic production of inorganic compounds or non-metals
    • C25B1/01Products
    • C25B1/02Hydrogen or oxygen
    • C25B1/04Hydrogen or oxygen by electrolysis of water
    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25BELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B9/00Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
    • C25B9/60Constructional parts of cells
    • C25B9/65Means for supplying current; Electrode connections; Electric inter-cell connections
    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25CPROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C1/00Electrolytic production, recovery or refining of metals by electrolysis of solutions
    • C25C1/06Electrolytic production, recovery or refining of metals by electrolysis of solutions or iron group metals, refractory metals or manganese

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Metallurgy (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Ceramic Engineering (AREA)
  • Structural Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • Mechanical Engineering (AREA)
  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)

Abstract

The invention belongs to the field of energy and metallurgy. Specifically, the invention discloses a system and a method for low-carbon electrometallurgical of iron ore. And purifying the iron concentrate through solid-phase enrichment, so as to reduce the impurity content in the subsequent electrolyte. Through reduction acidolysis, the acidolysis efficiency is improved, and low-acid conversion is realized. Through high-temperature desulfurization, the recycling utilization of acidolysis slag and purification slag and the recycling of sulfur element are realized. The high-temperature medium generated by the solar furnace is used for desulfurizing and supplying heat, so that low-carbonization of energy is realized. The high-temperature air is obtained through the sulfur dioxide heat exchanger, and is used for supplying heat for acidolysis and electrometallurgical processes, so that the high-efficiency utilization of heat is realized. The ferrous sulfate solution valence state adjustment, pure iron preparation, sulfuric acid regeneration and oxygen recycling are realized through electrometallurgy. The invention is suitable for large-scale continuous low-carbon electrometallurgical of iron ore and has the advantages of high efficiency, low energy consumption, no pollution, ultralow carbon dioxide emission and the like.

Description

System and method for low-carbon electrometallurgical of iron ore
Technical Field
The invention belongs to the field of energy and metallurgy, and particularly relates to a system and a method for low-carbon electrometallurgical of iron ore.
Background
The crude steel output of China in 2021 is about 10 hundred million tons, and the discharged CO 2 is about 18 hundred million tons, which accounts for 16 percent of the total discharged of China. The steel industry in China mainly uses the equal-length flow modes of a blast furnace and a converter (accounting for 90 percent of the flow), wherein blast furnace ironmaking is a main section for discharging CO 2, and accounts for about 70 percent of the whole flow. The blast furnace ironmaking uses coke as a reducing agent to remove oxygen in the iron ore, obtain molten iron and discharge a large amount of CO 2. The iron and steel industry is in need of developing a revolutionary low carbon iron making technology.
The currently developed ultra-low carbon iron making technology is mainly a technical route for replacing coke. Including hydrogen reduction instead of carbon reduction and electrical reduction instead of carbon reduction.
The hydrogen reduction route, namely, hydrogen production by water electrolysis and hydrogen reduction of iron. Patent CN112159880B discloses a method and apparatus for hydrogen-making, in which iron-ore-containing raw materials are subjected to microwave irradiation in a hydrogen or hydrogen-rich gas atmosphere to achieve hydrogen-rich or pure hydrogen-containing smelting of iron ore, and direct reduced iron can be obtained. Solves the problem that the reduction of iron oxide by hydrogen-rich gas in the existing hydrogen iron making still causes the discharge of a large amount of carbon dioxide. Patent application CN102586527a discloses a new process for smelting and reducing iron by hydrogen and carbon, the heat required by the whole process is provided by oxy-coal combustion and secondary combustion of reducing gas, and compared with the existing process, the emission of CO 2 is reduced by about 10%. Patent application CN105886688A discloses a green cyclic production system, in the metal smelting process, hydrogen replaces carbon to reduce iron ore into elemental iron, CO 2 is not generated in the process, water vapor generated by smelting generates electricity, and H 2 generated by electrolysis water is recycled. However, the current industrial water electrolysis hydrogen production is mainly an alkaline water solution system, the energy efficiency is about 60%, and the hydrogen production efficiency is low. In the process of reducing iron by hydrogen, the thermodynamic equilibrium is limited, so that the single conversion rate is low, multiple cycles are needed, and the energy consumption is increased. Meanwhile, the thermal effect of hydrogen to reduce iron is poor, and a large amount of heat energy needs to be additionally supplemented. Overall, "hydro metallurgy" consumes essentially green electrical energy, which is electro-metallurgy. The development of one-step electrochemical reduction of iron is also of great significance.
Under the electrochemical action, the iron ore can be decomposed into metallic iron and release oxygen. To achieve this, it is generally done in three typical systems, namely a high temperature molten salt/molten iron oxide system, an alkaline system and an acidic system. High temperature molten salt/molten iron oxide system. Patent application CN114232033A discloses a method for preparing high-purity iron by high-temperature fused salt electroreduction, which adopts a CaCl 2-Fe2O3 -CaO fused salt system, and under a certain current density and an inert atmosphere of argon at 850 ℃, a high-purity iron product with the purity of 99.94% can be obtained by fused salt electroreduction. Patent CN101906646B discloses a method for preparing metallic iron by electrolyzing iron ore with molten salt, which adopts Fe 2O3-Al2O3-SiO2 molten salt system, and obtains metallic iron by molten salt electroreduction under certain current density and electrolysis temperature (1580-1620 ℃). Patent CN109477232B discloses a preparation method of reducing iron by using an electrolytic deposition method through fused salt electroreduction under a certain voltage (1.5V/2.5V) and an electrolysis temperature (1000 ℃) by adopting a Na 2O2-B2O3-Fe2O3 fused salt system to obtain metal iron with 97% purity. At present, the main problems of the high-temperature molten salt/molten ferric oxide system are the development of economic inert anode materials, a proper electrolyte system, the purification of raw materials and the like.
An alkaline solution electroreduction iron-making technical route. Allanore A et al (DOI: 10.1149/1.2790285) have experimentally confirmed the possibility of iron formation by electrolytic suspension of a solution of iron oxide particles (iron ion concentration 2.6X10- -3 M) in a sodium hydroxide solution (mass concentration 50%, temperature 110 ℃ C.), but also mention the problem of very low reduction efficiency due to low hematite solubility in the system. Patent CN101696510B discloses a method and apparatus for preparing high-purity iron powder by electrolytic deoxidation, which relates to an electrochemical method for obtaining high-purity iron from solid iron oxide. The solid ferric oxide is a sintered body or ore with single or mixed Fe 2O3、Fe3O4 and FeO, the cathode and the anode are respectively positioned at two ends of the electrolytic tank, an ion conductor membrane and a high-temperature hydroxide solution (sodium hydroxide or potassium hydroxide, the temperature is 700-800 ℃) are arranged in the electrolytic tank, a preset voltage is arranged between the cathode and the anode to drive oxygen ions to diffuse from the ferric oxide in the cathode basket to the anode, and high-purity iron can be obtained on the cathode. However, the anode in the patent must be a solid material with strong alkali resistance, corrosion resistance and good conductivity, and the solid oxygen ion conductor membrane must also have the characteristics of alkali resistance and corrosion resistance, so that the cost is high. In addition, in order to prevent the dissolution of impurities in solid iron oxide in high-temperature alkaline solution from adversely affecting the electrolyte performance, the iron oxide needs to be subjected to impurity removal pretreatment, and this process leads to a significant increase in economic and environmental costs.
An acidic solution electroreduction process for preparing iron. Researchers have performed a great deal of work on the electroreduction of acidic iron-containing solutions to produce iron, primarily for the purpose of producing high purity metallic iron and pure iron powders. In this process, the most common electrolyte solutions are ferrous chloride and ferrous sulfate. The patent application CN107955952A discloses a method for producing high-purity iron powder by utilizing iron slag, which comprises the steps of removing inorganic components such as silicon dioxide and the like in the iron slag by leaching (the components of leaching liquid comprise 15-19 parts of sodium hydroxide, 5-9 parts of sodium methacrylate sulfonate and 260-300 parts of water), improving the content of iron particles in filter residues, adding electrolyte which comprises 6-9 parts of hydrochloric acid with the volume fraction of 15%, 10-14 parts of magnesium sulfate and 900-1000 parts of water for electrolysis, and finally cleaning the surface of the iron powder by utilizing ethylenediamine tetraacetic acid solution with the mass fraction of 18-22% to obtain the high-purity iron powder. In the patent, a large amount of sodium hydroxide and hydrochloric acid are consumed in the leaching and electrolysis processes, and the leaching liquid and the electrolyte cannot be recycled due to the influence of factors such as impurities and concentration, so that the subsequent treatment is difficult. Patent CN101517129B discloses an electrochemical method for recovering iron metal and chlorine from iron-rich metal chloride solution, the pH of the catholyte is 0.9-1.1, the electroreduction temperature is 80-85 ℃, the cathode current density is 200-500A/m 2, the current efficiency is 96.4% -97.9%, and the purity of the electroreduced iron is 99.99%. The patent has high requirements for the control of impurity content and pH in the solution, and requires the adjustment of the ferric chloride solution at a relatively low pH to prevent co-precipitation caused by the pH rising above the precipitation pH of the remaining impurities at the cathode surface, but also cannot be too low to prevent the evolution of byproduct hydrogen.
Acidic FeSO 4 electrolyte solution. Patent application CN113481540A discloses a method for preparing high-purity iron, which adopts a soluble anode, electrolyte mainly contains FeSO 4 and a small amount of stabilizer, the current density of the cathode is 100-230A/m 2, the pH value of the electrolyte is 1.00-4.00, the temperature of the electrolyte is 20-100 ℃, the purity of the electrolytically prepared iron is 99.90-99.99%, and the deposition thickness is 20 mu m-3 cm. The patent adopts a sulfuric acid system, and the soluble anode is industrial pure iron, low-carbon steel and the like, so that the electrolyte solution has higher purity. If the electrolyte purity is reduced, a plurality of side reactions, current efficiency reduction, impurity pollution and other problems are caused. Patent CN102084034B discloses an electrochemical method for recovering metallic iron or iron-rich alloy, oxygen and sulfuric acid from iron-rich metal sulfate waste (ilmenite sulfate method by-product), wherein electrolyte is iron-rich metal sulfate solution, pH of the electrolyte is 1.4-3.5, temperature of the electrolyte is 25-60 ℃, current density of a cathode used is 300-1000A/m 2, purity of prepared iron by electrolysis can reach 99.99%, and current efficiency is 95% -98%. The iron-rich metal sulfate solution in this patent must be pretreated (e.g., pH adjusted) and then electroreduced, and the acidic insoluble solids produced by this process are not readily handled. In addition, E.Mostad et al (DOI: 10.1016/j.hydromet.2007.07.014) mentioned that one of the smelters in Norway had been using pyrite (FeS 2) as a raw material during 1947 to 1957, and carried out semi-industrial tests on FeSO 4 solutions produced by calcination, sulfuric acid leaching and the like in pilot plant, to finally obtain high purity metallic iron. The process takes iron ore (pyrite) as a raw material for the first time, and produces metallic iron through electric reduction, and 1.5 multiplied by 10 5 kg of high-purity iron is produced in the two years 1955-1957, wherein the current efficiency reaches 85%, and the energy consumption is 4.25kWh/kg of iron. Badenhorst et al (DOI: 10.3390/membranes 9110137) found that the use of the novel BM-5AEM anion exchange membrane achieved a current efficiency of 95% for electrolytic iron, an energy consumption of 3.53kWh/kg iron, better stability and lower energy consumption than existing Pyror process flows. Meanwhile, the study found that when the concentration of iron in the solution was less than 5g/L, the side reaction of the cathode resulted in a decrease in the process efficiency. However, these documents mainly use pyrite or ferrous sulfate as a raw material, and are less studied for a wider range of hematite or magnetite. Patent applications WO2022204379A1 and WO2022197954A1 disclose a process for producing pure iron from iron ore and for removing impurities from the solution by first thermally reducing one or more non-magnetite iron oxide components of the iron ore in the presence of a reducing agent to form magnetite, then dissolving the magnetite using an acid to form an acidic iron salt solution, partially separating undissolved impurities, and then subjecting the acidic iron salt to electrolysis to obtain high purity iron, the remaining solution being recycled back to the acidolysis tank. However, the reducing agent mentioned in the patent is mainly hydrogen, and the hydrogen is generated by the chemical reaction of iron metal and acid, so that the cost is increased by adding iron metal, and meanwhile, a great amount of hydrogen and heat are easily and instantaneously generated by the exothermic reaction, so that the device and the safety are greatly influenced. In addition, the method reduces iron ore into magnetite by thermal reduction, that is, reduces the valence state of part of iron in the iron ore by thermal reduction means so as to promote dissolution of the ore, mainly because the higher the reduction degree of iron in the iron ore, the higher the leaching rate (DOI: 10.3321/j. Issn: 1005-3026.2008.12.017), but there is no mention in the patent of how reduction of the iron ore is achieved in an efficient manner, and the heat generated in the process cannot be recycled. In addition, the acidity of the acid used in the method for dissolving magnetite is high, and the acidity of the solution recycled back to the acidolysis tank after electrolysis is low, so that the problem that the magnetite is difficult to dissolve due to unmatched acidity is easily caused. Patent applications WO2022204387A1, WO2022204391A1 and WO2022204394A1 disclose a method for iron ore dissolution, conversion and systematic operation, in which iron-containing ore is dissolved into an acidic iron salt solution, fe 3+ is reduced in a first electrolytic cell to form Fe 2+, the Fe 2+ formed is subsequently transferred from the first electrolytic cell to a second electrolytic cell for reduction to high purity iron, and the remaining solution is returned to the dissolution tank. In the method, a Proton Exchange Membrane (PEM) and an Anion Exchange Membrane (AEM) are respectively adopted in the first electrolytic cell and the second electrolytic cell, and the types of the diaphragms of the electrolytic cells are increased by two different types of ion membranes, so that the use cost is increased. Also, it is mentioned in the patent that the volume of solution entering the cathode compartment is smaller than the volume of solution entering the anode compartment in the second electrolytic cell, which increases the complexity of the process and at the same time will lead to a reduced efficiency of iron utilization. Because hydrochloric acid is also used for dissolving magnetite in the patent, the introduction of chloride ions can lead to the occurrence of competitive reaction of the anode, increase the risk of separating out chlorine, and simultaneously easily aggravate the loss of an ionic membrane and increase the cost. In addition, the patent does not propose recycling of the precipitated oxygen.
Currently, ferrous electrolytes in acidic solution electroreduction iron production generally take ferrous iron as a main component, and raw materials mainly come from pyrite and ilmenite containing ferrous iron. When using the wider hematite or magnetite as raw materials, the related reports are less, and a series of new problems are faced: the acid production of the electroreduction anode is not matched with the acidity of the leaching electrode, and the acidity of the leaching final acid is not matched with the acidity of the electroreduction cathode, so that sulfuric acid medium is difficult to circulate, acidolysis is strengthened, water in membrane (ionic membrane) electroreduction is circulated, ferric sulfate solution is purified, acidolysis/purification slag is difficult to use, and the like. In summary, the current technology for producing iron by hydrogen reduction or electric reduction still has a restriction bottleneck. Therefore, by technological innovation, the development of a systematic new low-carbon electrometallurgical technology of iron ore has important significance.
Disclosure of Invention
Aiming at the problems, the invention provides a system and a method for low-carbon electrometallurgical of iron ore, so as to realize the efficient treatment of the large-scale continuous low-carbon electrometallurgical of the iron ore and the recycling of byproduct resources. In order to achieve the purpose, the invention adopts the following technical scheme:
The invention provides a low-carbon electrometallurgical method of iron ore, which comprises a solid-phase enrichment process 1, a reduction acidolysis process 2 and an electrometallurgical process 3;
The solid-phase enrichment process 1 comprises a fluidization magnetization roasting device 1-1, a mineral separation device 1-2 and an electrolytic water hydrogen production device 1-3;
the reduction acidolysis process 2 comprises an acidolysis filtering device 2-1, a purifying device 2-2, a high-temperature desulfurization device 2-3, a solar furnace 2-4, a sulfur dioxide heat exchanger 2-5, an acidolysis heat exchange device 2-6 and a sulfuric acid heat exchange device 2-7;
the electrometallurgical process 3 comprises an electroreduction device 3-1, an electrometallurgical device 3-2, a membrane separation device 3-3, a catholyte heat exchange device 3-4 and an anolyte heat exchange device 3-5;
The feed inlet of the fluidization magnetization roasting device 1-1 is connected with an iron concentrate feeding pipeline; the discharge port of the fluidization magnetization roasting device 1-1 is connected with the feed port of the beneficiation device 1-2 through a pipeline; the high-purity iron concentrate discharge port of the ore dressing device 1-2 is connected with the solid feed port of the acidolysis filtering device 2-1 through a pipeline; the gangue discharge port of the ore dressing device 1-2 is connected with the solid feed port of the high-temperature desulfurization device 2-3 through a pipeline; the liquid inlet of the electrolytic water hydrogen production device 1-3 is connected with an aqueous solution pipeline; the anode of the water electrolysis hydrogen production device 1-3 is connected with the anode of the direct current green electricity through a conductive copper beam; the cathode of the water electrolysis hydrogen production device 1-3 is connected with the cathode of the direct current green electricity through a conductive copper beam; the cathode hydrogen outlet of the electrolytic water hydrogen production device 1-3 is connected with the gas inlet of the fluidization magnetization roasting device 1-1 and the gas inlet of the high-temperature desulfurization device 2-3 through pipelines; the anode oxygen outlet of the electrolytic water hydrogen production device 1-3 is connected with an oxygen product pipeline; the fluidized magnetizing roasting device 1-1 is provided with a heat exchange jacket, and an inlet of the heat exchange jacket is connected with a solar furnace high-temperature medium through a pipeline; the outlet of the heat exchange jacket is connected with a solar furnace low-temperature medium through a pipeline;
The liquid feed inlet of the acidolysis filtering device 2-1 is connected with the liquid outlet of the acidolysis heat exchange device 2-6, the sulfuric acid solution outlet of the sulfuric acid heat exchange device 2-7, the low-temperature sulfur dioxide outlet of the sulfur dioxide heat exchanger 2-5 and the sulfuric acid solution main pipe through pipelines; the solid discharge port of the acidolysis filtering device 2-1 is connected with the solid feed port of the high-temperature desulfurization device 2-3 through a pipeline; the liquid outlet of the acidolysis filtering device 2-1 is connected with the liquid inlet of the purifying device 2-2 through a pipeline; the liquid outlet of the purification device 2-2 is connected with the liquid inlet of the catholyte heat exchange device 3-4 through a pipeline; the solid discharge port of the purification device 2-2 is connected with the solid feed port of the high-temperature desulfurization device 2-3 through a pipeline; the solid discharge port of the high-temperature desulfurization device 2-3 is connected with a cement clinker pipeline; the high-temperature sulfur dioxide outlet of the high-temperature desulfurization device 2-3 is connected with the high-temperature sulfur dioxide inlet of the sulfur dioxide heat exchanger 2-5 through a pipeline; the high-temperature desulfurization device 2-3 is provided with a heat exchange jacket, the inlet of the heat exchange jacket is connected with the high-temperature medium outlet of the solar furnace 2-4, and the outlet of the heat exchange jacket is connected with the low-temperature medium inlet of the solar furnace 2-4 through a pipeline; the solar furnace 2-4 can convert solar energy into heat energy; the normal temperature air inlet of the sulfur dioxide heat exchanger 2-5 is connected with an air pipeline; the high-temperature air outlet of the sulfur dioxide heat exchanger 2-5 is respectively connected with the air inlet of the catholyte heat exchange device 3-4, the air inlet of the anolyte heat exchange device 3-5 and the air inlet of the acidolysis heat exchange device 2-6 through pipelines; the liquid feed inlet of the acidolysis heat exchange device 2-6 is connected with the cathode liquid outlet of the electric reduction device 3-1 through a pipeline; the gas outlet of the acidolysis heat exchange device 2-6 is connected with a low-temperature air evacuation pipeline; the liquid inlet of the sulfuric acid heat exchange device 2-7 is connected with the sulfuric acid solution outlet of the electrometallurgical device 3-2 through a pipeline, and the gas outlet of the sulfuric acid heat exchange device 2-7 is connected with a low-temperature air evacuation pipeline;
The gas outlet of the catholyte heat exchange device 3-4 is connected with a low-temperature air evacuation pipeline; the liquid outlet of the catholyte heat exchange device 3-4 is connected with the catholyte inlet of the electro-reduction device 3-1 through a pipeline; the gas outlet of the anolyte heat exchange device 3-5 is connected with a low-temperature air evacuation pipeline; the liquid inlet of the anolyte heat exchange device 3-5 is connected with the anolyte outlet of the electro-reduction device 3-1 and the reclaimed water outlet of the membrane separation device 3-3 through a pipeline; the liquid outlet of the anolyte heat exchange device 3-5 is connected with the anolyte inlet of the electroreduction device 3-1 through a pipeline; the anode liquid outlet of the electro-reduction device 3-1 is connected with the anode liquid inlet of the electro-metallurgical device 3-2 through a pipeline; the anode gas outlet of the electroreduction device 3-1 is connected with an oxygen product pipeline; the cathode liquid outlet of the electro-reduction device 3-1 is connected with the cathode liquid inlet of the electro-metallurgical device 3-2 through a pipeline; the anode of the electric reduction device 3-1 is connected with the anode of the direct-current green electricity through a conductive copper beam; the cathode of the electric reduction device 3-1 is connected with the cathode of the direct-current green electricity through a conductive copper beam; the cathode liquid inlet of the electrometallurgical device 3-2 is connected with the ferrous sulfate discharge port of the membrane separation device 3-3 through a pipeline; the anode of the electrometallurgical device 3-2 is connected with the anode of the direct current green electricity through a conductive copper beam; the cathode of the electrometallurgical device 3-2 is connected with the cathode of the direct current green electricity through a conductive copper beam; the anode gas outlet of the electrometallurgical device 3-2 is connected with an oxygen product pipeline; the cathode liquid outlet of the electrometallurgical device 3-2 is connected with the liquid inlet of the membrane separation device 3-3 through a pipeline; the cathode gas outlet of the electrometallurgical device 3-2 is connected with the hydrogen outlet and the hydrogen product inlet of the electrolyzed water hydrogen production device 1-3 through pipelines; the pure iron outlet of the electrometallurgical device 3-2 is designed to be open.
The invention discloses a low-carbon electrometallurgical method for iron ore based on the system, which comprises the following steps of:
The iron concentrate is sent into the fluidization magnetization roasting device 1-1 to undergo a reduction reaction with green hydrogen from the electrolytic water hydrogen production device 1-3 and the electrometallurgical device 3-2 to obtain magnetic iron ore; the solar furnace high-temperature medium provides heat for reduction reaction through a heat exchange jacket in the fluidization magnetization roasting device 1-1; the magnetic iron ore passes through the ore dressing device 1-2 to obtain high-purity iron fine powder and gangue; delivering the high-purity iron concentrate to the acidolysis filtering device 2-1; the gangue is sent to the high-temperature desulfurization device 2-3;
In the acidolysis filtering device 2-1, high-purity iron fine powder and concentrated sulfuric acid from a liquid outlet of the sulfuric acid heat exchange device 2-7, ferrous sulfate entering a liquid outlet of the acidolysis heat exchange device 2-6 through a liquid outlet of a cathode chamber of the electric reduction device 3-1, and low-temperature sulfur dioxide at a gas outlet of the sulfur dioxide heat exchanger 2-5 undergo a reduction acidolysis reaction to obtain acidolysis slurry; the sulfuric acid solution is used for starting the system for the first time; filtering acidolysis slurry to obtain acidolysis slag and acid leaching solution; delivering acidolysis slag to the high-temperature desulfurization device 2-3 for treatment; the acid leaching solution is sent to the purification device 2-2 for treatment; in the high-temperature desulfurization device 2-3, gangue, acidolysis slag and purified slag from the purification device 2-2 are subjected to high-temperature desulfurization reaction in the presence of hydrogen to obtain sulfur dioxide gas and cement clinker; delivering and utilizing cement clinker; the sulfur dioxide gas heats air through the sulfur dioxide heat exchanger 2-5, and the heated high-temperature air provides heat required by reaction for acidolysis working procedures and electrometallurgical working procedures respectively; the solar furnace 2-4 converts solar energy into heat energy to generate a high-temperature medium, and the high-temperature medium provides heat for desulfurization reaction through a heat exchange jacket in the high-temperature desulfurization device 2-3; returning the low-temperature medium subjected to heat exchange to the solar furnace; in the purifying device 2-2, the purified ferric sulfate solution is heated by a catholyte heat exchange device 3-4 and then sent to the electro-reduction device 3-1;
In the electroreduction device 3-1, cathode room ferric sulfate is reduced into ferrous sulfate under the action of direct current, when the concentration of sulfuric acid in ferrous sulfate solution is higher than 5g/L, the ferrous sulfate solution is preheated by the acidolysis heat exchange device 2-6 and then is sent into the acidolysis filtering device 2-1; when the concentration of sulfuric acid in the ferrous sulfate solution is lower than 5g/L, the ferrous sulfate solution is fed into the electrometallurgical device 3-2; the solution in the anode chamber of the electroreduction device 3-1 is subjected to direct current to separate out oxygen and generate sulfuric acid; an oxygen product delivery pipe; mixing 1% -20% of the sulfuric acid solution with the regenerated water generated by the membrane separation device 3-3, circulating to the anolyte heat exchange device 3-5, entering the anolyte inlet of the electroreduction device 3-1, and delivering the rest sulfuric acid solution into the anode chamber of the electrowinning device 3-2; in the electrometallurgical device 3-2, ferrous sulfate solution from a cathode chamber of the electroreduction device 3-1 and the membrane separation device 3-3 is reduced into pure iron under the action of direct current, hydrogen is by-produced, and residual dilute ferrous sulfate solution is left; hydrogen is sent to the fluidization magnetization roasting device 1-1 and the high temperature desulfurization device 2-3 for utilization or used as a hydrogen product; delivering the dilute ferrous sulfate solution to the membrane separation device 3-3; under the action of direct current, the solution in the anode chamber of the electrowinning device 3-2 is separated out of oxygen to generate sulfuric acid; an oxygen product delivery pipe; the concentrated sulfuric acid is preheated by the sulfuric acid heat exchange device 2-7 and then is sent to the acidolysis filtering device 2-1.
One of the features of the present invention is that: the fluidization magnetization roasting device 1-1 adopts a fluidized bed reactor, green hydrogen is used as a reducing agent, and a solar furnace high-temperature medium provides heat; the reaction temperature is 300-800 ℃, and the residence time is as follows: 5min-30min.
The second feature of the present invention is that: the beneficiation device 1-2 obtains high-purity iron concentrate, and the grade of ferric oxide is not lower than 94%.
The third feature of the present invention is that: in the acidolysis filter device 2-1, the sulfuric acid solution is used for starting the system for the first time, the concentration of the concentrated sulfuric acid solution is not lower than 100g/L, and the acidolysis temperature of the high-purity iron concentrate powder is 50-100 ℃.
The fourth feature of the invention is that: in the acidolysis filter device 2-1, ferric ions generated in the acidolysis process are reduced into ferrous ions under the actions of sulfur dioxide chemical reduction and the electric reduction device 3-1, so that the reduction acidolysis is realized, the acidolysis rate of the high-purity iron concentrate is improved, and the acidolysis rate is more than 98%.
The fifth characteristic of the invention is that: in the high-temperature desulfurization device 2-3, a fluidized bed or rotary kiln reactor is adopted, a solar furnace high-temperature medium provides heat, the reaction temperature is 1000-1500 ℃, and the desulfurization rate is more than 99%.
The sixth feature of the invention is that: in the electro-reduction device 3-1, the diaphragm is made of an ionic membrane or a porous membrane, wherein the seepage rate of the porous membrane is 1% -30%, the electro-reduction current density is 50A/m 2-1000A/m2, the anode is a lead alloy or titanium-based ruthenium iridium tantalum coating electrode, the cathode comprises one or more of iron, copper, titanium and stainless steel, and the electro-reduction temperature is 20 ℃ -100 ℃.
The seventh feature of the invention is that: in the electrometallurgical device 3-2, the diaphragm is made of an ionic membrane or a porous membrane, wherein the seepage rate of the porous membrane is 1% -30%, the electroreduction current density is 50A/m 2-1000A/m2, the anode is a lead alloy or titanium-based ruthenium iridium tantalum coating electrode, the cathode comprises one or more of iron, copper, titanium and stainless steel materials, the electroreduction temperature is 60-100 ℃, the current efficiency is above 95%, the purity of the cathode iron is above 99%, and the direct current consumption of each ton of iron is lower than 3450kWh.
The eighth feature of the present invention is that: the membrane separation device 3-3 comprises one or more of reverse osmosis, ultrafiltration, nanofiltration and electrodialysis.
The ninth aspect of the present invention is characterized in that: the solar furnace 2-4 converts solar energy into heat energy, the solar heating medium can be molten salt and/or gas, the molten salt comprises one or more of elements such as silicon, sodium, oxygen, calcium, aluminum and the like, the gas comprises nitrogen and/or argon, namely, the heating medium can be molten salt comprising elements such as silicon, sodium, oxygen, calcium, aluminum and the like, and can also be gas comprising nitrogen, argon and mixed gas thereof.
The invention is characterized in that: the beneficiation gangue is added into the high-temperature desulfurization process, and the silicon oxide in the gangue can obviously improve the desulfurization efficiency.
According to the invention, the iron concentrate is purified through solid-phase enrichment, so that the impurity content in the subsequent electrolyte is reduced. Through reduction acidolysis, the acidolysis efficiency is improved, and low-acid conversion is realized. Through high-temperature desulfurization, the recycling utilization of acidolysis slag and purification slag and the recycling of sulfur element are realized. The ferrous sulfate solution valence state adjustment, pure iron preparation, sulfuric acid regeneration and oxygen recycling are realized through electrometallurgy. The high-temperature medium generated by the solar furnace is used for desulfurizing and supplying heat, so that low-carbonization of energy is realized. The high-temperature air is obtained through the sulfur dioxide heat exchanger, and is used for supplying heat for acidolysis and electrometallurgical processes, so that the high-efficiency utilization of heat is realized.
Compared with the prior art, the invention has the following outstanding advantages:
(1) The energy source for producing hydrogen by electrolyzing water is green electric energy, and the produced hydrogen and oxygen can be recycled;
(2) The sulfur element can be recycled in the system without emission, so that the system is safe and environment-friendly;
(3) The produced gangue, acidolysis slag and purification slag can be recycled to be made into cement clinker;
(4) The process is simple, the production cost is low, and the product purity is high;
(5) Realizing ultralow emission of carbon dioxide;
The method for low-carbon electrometallurgical of iron ore can not only obtain high-purity iron, but also realize the recycling of gangue, acidolysis slag and purification slag and the recycling of sulfuric acid byproducts. The invention is suitable for large-scale continuous low-carbon electrometallurgical of iron ore and has the advantages of high efficiency, low energy consumption, no pollution, ultralow carbon dioxide emission and the like.
Drawings
Fig. 1 is a schematic configuration diagram of a low-carbon electrometallurgical system of iron ore.
Reference numerals
The method comprises the steps of (1) a solid-phase enrichment process, (1-1) a fluidization magnetization roasting device, (1-2) a mineral separation device, (1-3) an electrolytic water hydrogen production device, (2) a reduction acidolysis process, (2-1) an acidolysis filtering device, (2-2) a purification device, (2-3) a high-temperature desulfurization device, (2-4) a solar furnace, (2-5) a sulfur dioxide heat exchanger, (2-6) an acidolysis heat exchange device, (2-7) a sulfuric acid heat exchange device, (3) an electrometallurgical process (3-1) an electroreduction device, (3-2) an electrometallurgical device, (3-3) a membrane separation device, (3-4) a catholyte heat exchange device and (3-5) an anolyte heat exchange device.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. It should be noted that the examples are only for illustrating the technical scheme of the present invention and are not limiting. FIG. 1 is a schematic diagram of a low-carbon electrometallurgical system and method for iron ore according to the present invention.
Example 1
Referring to fig. 1, the low-carbon electrometallurgical system of iron ore used in the present embodiment includes a solid-phase enrichment process 1, a reductive acidolysis process 2, and an electrometallurgical process 3;
The solid-phase enrichment process 1 comprises a fluidization magnetization roasting device 1-1, a mineral separation device 1-2 and an electrolytic water hydrogen production device 1-3;
the reduction acidolysis process 2 comprises an acidolysis filtering device 2-1, a purifying device 2-2, a high-temperature desulfurization device 2-3, a solar furnace 2-4, a sulfur dioxide heat exchanger 2-5, an acidolysis heat exchange device 2-6 and a sulfuric acid heat exchange device 2-7;
the electrometallurgical process 3 comprises an electroreduction device 3-1, an electrometallurgical device 3-2, a membrane separation device 3-3, a catholyte heat exchange device 3-4 and an anolyte heat exchange device 3-5;
The feed inlet of the fluidization magnetization roasting device 1-1 is connected with an iron concentrate feeding pipeline; the discharge port of the fluidization magnetization roasting device 1-1 is connected with the feed port of the beneficiation device 1-2 through a pipeline; the high-purity iron concentrate discharge port of the ore dressing device 1-2 is connected with the solid feed port of the acidolysis filtering device 2-1 through a pipeline; the gangue discharge port of the ore dressing device 1-2 is connected with the solid feed port of the high-temperature desulfurization device 2-3 through a pipeline; the liquid inlet of the electrolytic water hydrogen production device 1-3 is connected with an aqueous solution pipeline; the anode of the water electrolysis hydrogen production device 1-3 is connected with the anode of the direct current green electricity through a conductive copper beam; the cathode of the water electrolysis hydrogen production device 1-3 is connected with the cathode of the direct current green electricity through a conductive copper beam; the cathode hydrogen outlet of the electrolytic water hydrogen production device 1-3 is connected with the gas inlet of the fluidization magnetization roasting device 1-1 and the gas inlet of the high-temperature desulfurization device 2-3 through pipelines; the anode oxygen outlet of the electrolytic water hydrogen production device 1-3 is connected with an oxygen product pipeline; the fluidized magnetizing roasting device 1-1 is provided with a heat exchange jacket, and an inlet of the heat exchange jacket is connected with a solar furnace high-temperature medium through a pipeline; the outlet of the heat exchange jacket is connected with a solar furnace low-temperature medium through a pipeline;
The liquid feed inlet of the acidolysis filtering device 2-1 is connected with the liquid outlet of the acidolysis heat exchange device 2-6, the sulfuric acid solution outlet of the sulfuric acid heat exchange device 2-7, the low-temperature sulfur dioxide outlet of the sulfur dioxide heat exchanger 2-5 and the sulfuric acid solution main pipe through pipelines; the solid discharge port of the acidolysis filtering device 2-1 is connected with the solid feed port of the high-temperature desulfurization device 2-3 through a pipeline; the liquid outlet of the acidolysis filtering device 2-1 is connected with the liquid inlet of the purifying device 2-2 through a pipeline; the liquid outlet of the purification device 2-2 is connected with the liquid inlet of the catholyte heat exchange device 3-4 through a pipeline; the solid discharge port of the purification device 2-2 is connected with the solid feed port of the high-temperature desulfurization device 2-3 through a pipeline; the solid discharge port of the high-temperature desulfurization device 2-3 is connected with a cement clinker pipeline; the high-temperature sulfur dioxide outlet of the high-temperature desulfurization device 2-3 is connected with the high-temperature sulfur dioxide inlet of the sulfur dioxide heat exchanger 2-5 through a pipeline; the high-temperature desulfurization device 2-3 is provided with a heat exchange jacket, the inlet of the heat exchange jacket is connected with the high-temperature medium outlet of the solar furnace 2-4, and the outlet of the heat exchange jacket is connected with the low-temperature medium inlet of the solar furnace 2-4 through a pipeline; the solar furnace 2-4 can convert solar energy into heat energy; the normal temperature air inlet of the sulfur dioxide heat exchanger 2-5 is connected with an air pipeline; the high-temperature air outlet of the sulfur dioxide heat exchanger 2-5 is respectively connected with the air inlet of the catholyte heat exchange device 3-4, the air inlet of the anolyte heat exchange device 3-5 and the air inlet of the acidolysis heat exchange device 2-6 through pipelines; the liquid feed inlet of the acidolysis heat exchange device 2-6 is connected with the cathode liquid outlet of the electric reduction device 3-1 through a pipeline; the gas outlet of the acidolysis heat exchange device 2-6 is connected with a low-temperature air evacuation pipeline; the liquid inlet of the sulfuric acid heat exchange device 2-7 is connected with the sulfuric acid solution outlet of the electrometallurgical device 3-2 through a pipeline, and the gas outlet of the sulfuric acid heat exchange device 2-7 is connected with a low-temperature air evacuation pipeline;
The gas outlet of the catholyte heat exchange device 3-4 is connected with a low-temperature air evacuation pipeline; the liquid outlet of the catholyte heat exchange device 3-4 is connected with the catholyte inlet of the electro-reduction device 3-1 through a pipeline; the gas outlet of the anolyte heat exchange device 3-5 is connected with a low-temperature air evacuation pipeline; the liquid inlet of the anolyte heat exchange device 3-5 is connected with the anolyte outlet of the electro-reduction device 3-1 and the reclaimed water outlet of the membrane separation device 3-3 through a pipeline; the liquid outlet of the anolyte heat exchange device 3-5 is connected with the anolyte inlet of the electroreduction device 3-1 through a pipeline; the anode liquid outlet of the electro-reduction device 3-1 is connected with the anode liquid inlet of the electro-metallurgical device 3-2 through a pipeline; the anode gas outlet of the electroreduction device 3-1 is connected with an oxygen product pipeline; the cathode liquid outlet of the electro-reduction device 3-1 is connected with the cathode liquid inlet of the electro-metallurgical device 3-2 through a pipeline; the anode of the electric reduction device 3-1 is connected with the anode of the direct-current green electricity through a conductive copper beam; the cathode of the electric reduction device 3-1 is connected with the cathode of the direct-current green electricity through a conductive copper beam; the cathode liquid inlet of the electrometallurgical device 3-2 is connected with the ferrous sulfate discharge port of the membrane separation device 3-3 through a pipeline; the anode of the electrometallurgical device 3-2 is connected with the anode of the direct current green electricity through a conductive copper beam; the cathode of the electrometallurgical device 3-2 is connected with the cathode of the direct current green electricity through a conductive copper beam; the anode gas outlet of the electrometallurgical device 3-2 is connected with an oxygen product pipeline; the cathode liquid outlet of the electrometallurgical device 3-2 is connected with the liquid inlet of the membrane separation device 3-3 through a pipeline; the cathode gas outlet of the electrometallurgical device 3-2 is connected with the hydrogen outlet and the hydrogen product inlet of the electrolyzed water hydrogen production device 1-3 through pipelines; the pure iron outlet of the electrometallurgical device 3-2 is designed to be open.
Example 2
The embodiment adopts the method for low-carbon electrometallurgical of the system iron ore, which comprises the following steps:
The iron concentrate is sent into the fluidization magnetization roasting device 1-1 to undergo a reduction reaction with green hydrogen from the electrolytic water hydrogen production device 1-3 and the electrometallurgical device 3-2 to obtain magnetic iron ore; the solar furnace high-temperature medium provides heat for reduction reaction through a heat exchange jacket in the fluidization magnetization roasting device 1-1; the magnetic iron ore passes through the ore dressing device 1-2 to obtain high-purity iron fine powder and gangue; delivering the high-purity iron concentrate to the acidolysis filtering device 2-1; the gangue is sent to the high-temperature desulfurization device 2-3;
In the acidolysis filtering device 2-1, high-purity iron fine powder and concentrated sulfuric acid from a liquid outlet of the sulfuric acid heat exchange device 2-7, ferrous sulfate entering a liquid outlet of the acidolysis heat exchange device 2-6 through a liquid outlet of a cathode chamber of the electric reduction device 3-1, and low-temperature sulfur dioxide at a gas outlet of the sulfur dioxide heat exchanger 2-5 undergo a reduction acidolysis reaction to obtain acidolysis slurry; the sulfuric acid solution is used for starting the system for the first time; filtering acidolysis slurry to obtain acidolysis slag and acid leaching solution; delivering acidolysis slag to the high-temperature desulfurization device 2-3 for treatment; the acid leaching solution is sent to the purification device 2-2 for treatment; in the high-temperature desulfurization device 2-3, gangue, acidolysis slag and purified slag from the purification device 2-2 are subjected to high-temperature desulfurization reaction in the presence of hydrogen to obtain sulfur dioxide gas and cement clinker; delivering and utilizing cement clinker; the sulfur dioxide gas heats air through the sulfur dioxide heat exchanger 2-5, and the heated high-temperature air provides heat required by reaction for acidolysis working procedures and electrometallurgical working procedures respectively; the solar furnace 2-4 converts solar energy into heat energy to generate a high-temperature medium, and the high-temperature medium provides heat for desulfurization reaction through a heat exchange jacket in the high-temperature desulfurization device 2-3; returning the low-temperature medium subjected to heat exchange to the solar furnace; in the purifying device 2-2, the purified ferric sulfate solution is heated by a catholyte heat exchange device 3-4 and then sent to the electro-reduction device 3-1;
in the electroreduction device 3-1, cathode room ferric sulfate is reduced into ferrous sulfate under the action of direct current, when the concentration of sulfuric acid in ferrous sulfate solution is higher than 5g/L, the ferrous sulfate solution is preheated by the acidolysis heat exchange device 2-6 and then is sent into the acidolysis filtering device 2-1; when the concentration of sulfuric acid in the ferrous sulfate solution is lower than 5g/L, the ferrous sulfate solution is fed into the electrometallurgical device 3-2; the solution in the anode chamber of the electroreduction device 3-1 is subjected to direct current to separate out oxygen and generate sulfuric acid; an oxygen product delivery pipe; 10% of the sulfuric acid solution is mixed with the regenerated water generated by the membrane separation device 3-3, circulated to the anolyte heat exchange device 3-5, then enters the anolyte inlet of the electroreduction device 3-1, and the rest sulfuric acid solution is sent into the anode chamber of the electrometallurgical device 3-2; in the electrometallurgical device 3-2, ferrous sulfate solution from a cathode chamber of the electroreduction device 3-1 and the membrane separation device 3-3 is reduced into pure iron under the action of direct current, hydrogen is by-produced, and residual dilute ferrous sulfate solution is left; hydrogen is sent to the fluidization magnetization roasting device 1-1 and the high temperature desulfurization device 2-3 for utilization or used as a hydrogen product; delivering the dilute ferrous sulfate solution to the membrane separation device 3-3; under the action of direct current, the solution in the anode chamber of the electrowinning device 3-2 is separated out of oxygen to generate sulfuric acid; an oxygen product delivery pipe; the concentrated sulfuric acid is preheated by the sulfuric acid heat exchange device 2-7 and then is sent to the acidolysis filtering device 2-1.
Example 3
In the embodiment, iron ore of a certain enterprise is used as a processing object. A fluidized bed reactor is adopted in the fluidization magnetization roasting device 1-1, the reaction temperature is 300 ℃, and the residence time is 30min; the grade of ferric oxide of the high-purity iron concentrate obtained in the ore dressing device 1-2 is 94%; the sulfuric acid solution in the acidolysis filter device 2-1 is used for starting the system for the first time, the concentration is 100g/L, the acidolysis temperature of the high-purity fine iron powder is 50 ℃, and the acidolysis rate of the fine iron powder is 98%; the high-temperature desulfurization device 2-3 adopts a fluidized bed reactor, the reaction temperature is 1000 ℃, and the desulfurization rate reaches 99%; in the electro-reduction device 3-1, the diaphragm is made of an ionic membrane, the electro-reduction current density is 50A/m 2, and the electro-reduction temperature is 20 ℃; the anode is a lead alloy or titanium-based ruthenium iridium tantalum coating electrode, and the cathode is made of iron, copper, titanium or stainless steel; in the electrometallurgical device 3-2, the diaphragm is made of an ionic membrane, the electric reduction current density is 50A/m 2, the electric reduction temperature is 60 ℃, the current efficiency is 95%, the purity of cathode iron is 99%, and the direct current consumption of each ton of iron is 3450kWh; the anode is a lead alloy or titanium-based ruthenium iridium tantalum coating electrode, and the cathode is made of iron, copper, titanium or stainless steel. Solar energy is converted into heat energy by solar furnace 2-4, and the solar energy is used as a heating medium, wherein the medium is mixed molten salt of sodium aluminosilicate and calcium aluminosilicate. The membrane separation device 3-3 adopts a reverse osmosis mode.
Example 4
In the embodiment, iron ore of a certain enterprise is used as a processing object. A fluidized bed reactor is adopted in the fluidization magnetization roasting device 1-1, the reaction temperature is 500 ℃, and the residence time is 15min; the grade of ferric oxide of the high-purity iron concentrate obtained in the ore dressing device 1-2 is 96%; the sulfuric acid solution in the acidolysis filter device 2-1 is used for starting the system for the first time, the concentration is 120g/L, the acidolysis temperature of the high-purity fine iron powder is 80 ℃, and the acidolysis rate of the fine iron powder is 99%; the high-temperature desulfurization device 2-3 adopts a fluidized bed reactor, the reaction temperature is 1100 ℃, and the desulfurization rate reaches 99.8%; in the electroreduction device 3-1, the membrane is made of a porous membrane, wherein the seepage rate of the porous membrane is 1%, the electroreduction current density is 500A/m 2, and the electroreduction temperature is 60 ℃; the anode is a lead alloy or titanium-based ruthenium iridium tantalum coating electrode, and the cathode is made of iron, copper, titanium or stainless steel; in the electrometallurgical device 3-2, the diaphragm is made of a porous film, wherein the seepage rate of the porous film is 1%, the electric reduction current density is 500A/m 2, the electric reduction temperature is 80 ℃, the current efficiency is 98%, the purity of cathode iron is 99.5%, and the direct current consumption of each ton of iron is lower than 3390kWh; the anode is a lead alloy or titanium-based ruthenium iridium tantalum coating electrode, and the cathode is made of iron, copper, titanium or stainless steel. Solar furnace 2-4 converts solar energy into heat energy, and the solar energy heats a medium, wherein the medium is a mixed gas of nitrogen and argon. The membrane separation device 3-3 adopts an ultrafiltration mode.
Example 5
In the embodiment, iron ore of a certain enterprise is used as a processing object. A fluidized bed reactor is adopted in the fluidization magnetization roasting device 1-1, the reaction temperature is 800 ℃, and the residence time is 5min; the grade of ferric oxide of the high-purity iron concentrate obtained in the ore dressing device 1-2 is 98%; the sulfuric acid solution in the acidolysis filter device 2-1 is used for starting the system for the first time, the concentration is 150g/L, the acidolysis temperature of the high-purity fine iron powder is 100 ℃, and the acidolysis rate of the fine iron powder is 99%; the high-temperature desulfurization device 2-3 adopts a rotary kiln reactor, the reaction temperature is 1500 ℃, and the desulfurization rate reaches 99.9%; in the electroreduction device 3-1, the membrane is made of a porous membrane, wherein the seepage rate of the porous membrane is 30%, the electroreduction current density is 1000A/m 2, and the electroreduction temperature is 100 ℃; the anode is a lead alloy or titanium-based ruthenium iridium tantalum coating electrode, and the cathode is made of iron, copper, titanium or stainless steel; in the electrometallurgical device 3-2, the diaphragm is made of a porous film, wherein the seepage rate of the porous film is 30%, the electric reduction current density is 1000A/m 2, the electric reduction temperature is 100 ℃, the current efficiency is 99%, the purity of cathode iron is 99.9%, and the direct current consumption of each ton of iron is lower than 3210kWh; the anode is a lead alloy or titanium-based ruthenium iridium tantalum coating electrode, and the cathode is made of iron, copper, titanium or stainless steel. Solar furnace 2-4 converts solar energy into heat energy, and the solar energy heats a medium, wherein the medium is a mixed gas of nitrogen and argon. The membrane separation device 3-3 adopts a nanofiltration mode.
The invention is not described in detail in part as being well known in the art.
There are, of course, many embodiments of the invention that can be varied and modified from the teachings of this invention by those skilled in the art, and that such variations and modifications are within the scope of the appended claims without departing from the spirit and the substance of the invention.

Claims (10)

1. A low-carbon electrometallurgical system of iron ores, which is characterized by comprising a solid-phase enrichment process (1), a reduction acidolysis process (2) and an electrometallurgical process (3);
The solid-phase enrichment process (1) comprises a fluidization magnetization roasting device (1-1), a mineral separation device (1-2) and an electrolytic water hydrogen production device (1-3);
The reduction acidolysis process (2) comprises an acidolysis filtering device (2-1), a purifying device (2-2), a high-temperature desulfurizing device (2-3), a solar furnace (2-4), a sulfur dioxide heat exchanger (2-5), an acidolysis heat exchanging device (2-6) and a sulfuric acid heat exchanging device (2-7);
The electrometallurgical process (3) comprises an electroreduction device (3-1), an electrometallurgical device (3-2), a membrane separation device (3-3), a catholyte heat exchange device (3-4) and an anolyte heat exchange device (3-5);
the feed inlet of the fluidization magnetization roasting device (1-1) is connected with an iron concentrate feeding pipeline; the discharge port of the fluidization magnetization roasting device (1-1) is connected with the feed port of the mineral separation device (1-2) through a pipeline; the high-purity iron fine powder discharge port of the ore dressing device (1-2) is connected with the solid feed port of the acidolysis filtering device (2-1) through a pipeline; the gangue discharge port of the ore dressing device (1-2) is connected with the solid feed port of the high-temperature desulfurization device (2-3) through a pipeline; the liquid inlet of the electrolytic water hydrogen production device (1-3) is connected with an aqueous solution pipeline; the anode of the water electrolysis hydrogen production device (1-3) is connected with the anode of the direct current green electricity through a conductive copper beam; the cathode of the water electrolysis hydrogen production device (1-3) is connected with the cathode of the direct current green electricity through a conductive copper beam; the cathode hydrogen outlet of the electrolytic water hydrogen production device (1-3) is connected with the gas inlet of the fluidization magnetization roasting device (1-1) and the gas inlet of the high-temperature desulfurization device (2-3) through a pipeline; the anode oxygen outlet of the electrolytic water hydrogen production device (1-3) is connected with an oxygen product pipeline; the fluidized magnetizing roasting device (1-1) is provided with a heat exchange jacket, and an inlet of the heat exchange jacket is connected with a solar furnace high-temperature medium through a pipeline; the outlet of the heat exchange jacket is connected with a solar furnace low-temperature medium through a pipeline;
The liquid feed inlet of the acidolysis filtering device (2-1) is connected with the liquid outlet of the acidolysis heat exchange device (2-6), the sulfuric acid solution outlet of the sulfuric acid heat exchange device (2-7), the low-temperature sulfur dioxide outlet of the sulfur dioxide heat exchanger (2-5) and the sulfuric acid solution main pipe through pipelines; the solid discharge port of the acidolysis filtering device (2-1) is connected with the solid feed port of the high-temperature desulfurizing device (2-3) through a pipeline; the liquid outlet of the acidolysis filtering device (2-1) is connected with the liquid inlet of the purifying device (2-2) through a pipeline; the liquid outlet of the purifying device (2-2) is connected with the liquid inlet of the catholyte heat exchange device (3-4) through a pipeline; the solid discharge port of the purification device (2-2) is connected with the solid feed port of the high-temperature desulfurization device (2-3) through a pipeline; the solid discharge port of the high-temperature desulfurization device (2-3) is connected with a cement clinker pipeline; the high-temperature sulfur dioxide outlet of the high-temperature desulfurization device (2-3) is connected with the high-temperature sulfur dioxide inlet of the sulfur dioxide heat exchanger (2-5) through a pipeline; the high-temperature desulfurization device (2-3) is provided with a heat exchange jacket, the inlet of the heat exchange jacket is connected with the high-temperature medium outlet of the solar furnace (2-4), and the outlet of the heat exchange jacket is connected with the low-temperature medium inlet of the solar furnace (2-4) through a pipeline; the solar furnace (2-4) converts solar energy into heat energy; the normal temperature air inlet of the sulfur dioxide heat exchanger (2-5) is connected with an air pipeline; the high-temperature air outlet of the sulfur dioxide heat exchanger (2-5) is respectively connected with the air inlet of the catholyte heat exchange device (3-4), the air inlet of the anolyte heat exchange device (3-5) and the air inlet of the acidolysis heat exchange device (2-6) through pipelines; the liquid feed inlet of the acidolysis heat exchange device (2-6) is connected with the cathode liquid outlet of the electric reduction device (3-1) through a pipeline; the gas outlet of the acidolysis heat exchange device (2-6) is connected with a low-temperature air evacuation pipeline; the liquid inlet of the sulfuric acid heat exchange device (2-7) is connected with the sulfuric acid solution outlet of the electrometallurgical device (3-2) through a pipeline, and the gas outlet of the sulfuric acid heat exchange device (2-7) is connected with a low-temperature air evacuation pipeline;
The gas outlet of the catholyte heat exchange device (3-4) is connected with a low-temperature air evacuation pipeline; the liquid outlet of the catholyte heat exchange device (3-4) is connected with the catholyte inlet of the electro-reduction device (3-1) through a pipeline; the gas outlet of the anolyte heat exchange device (3-5) is connected with a low-temperature air evacuation pipeline; the liquid inlet of the anolyte heat exchange device (3-5) is connected with the anolyte outlet of the electric reduction device (3-1) and the reclaimed water outlet of the membrane separation device (3-3) through a pipeline; the liquid outlet of the anolyte heat exchange device (3-5) is connected with the anolyte inlet of the electric reduction device (3-1) through a pipeline; the anode liquid outlet of the electro-reduction device (3-1) is connected with the anode liquid inlet of the electro-metallurgical device (3-2) through a pipeline; the anode gas outlet of the electric reduction device (3-1) is connected with an oxygen product pipeline; the cathode liquid outlet of the electro-reduction device (3-1) is connected with the cathode liquid inlet of the electro-metallurgical device (3-2) through a pipeline; the anode of the electric reduction device (3-1) is connected with the anode of the direct-current green electricity through a conductive copper beam; the cathode of the electric reduction device (3-1) is connected with the cathode of the direct-current green electricity through a conductive copper beam; the cathode liquid inlet of the electrometallurgical device (3-2) is connected with the ferrous sulfate discharge port of the membrane separation device (3-3) through a pipeline; the anode of the electrometallurgical device (3-2) is connected with the anode of the direct current green electricity through a conductive copper beam; the cathode of the electrometallurgical device (3-2) is connected with the cathode of the direct current green electricity through a conductive copper beam; the anode gas outlet of the electrometallurgical device (3-2) is connected with an oxygen product pipeline; the cathode liquid outlet of the electrometallurgical device (3-2) is connected with the liquid inlet of the membrane separation device (3-3) through a pipeline; the cathode air outlet of the electrometallurgical device (3-2) is connected with the hydrogen outlet and the hydrogen product inlet of the electrolyzed water hydrogen production device (1-3) through pipelines; the pure iron outlet of the electrometallurgical device (3-2) is designed to be open.
2. A method of low carbon electrometallurgical process of iron ore based on the system of claim 1, comprising the steps of:
The iron concentrate is sent into the fluidization magnetization roasting device (1-1) to undergo a reduction reaction with green hydrogen from the electrolytic water hydrogen production device (1-3) and the electrometallurgical device (3-2) to obtain magnetic iron ore; the solar furnace high-temperature medium provides heat for reduction reaction through a heat exchange jacket in the fluidization magnetization roasting device (1-1); the magnetic iron ore passes through the ore dressing device (1-2) to obtain high-purity iron fine powder and gangue; the high-purity iron concentrate is sent to the acidolysis filtering device (2-1); the gangue is sent to the high-temperature desulfurization device (2-3);
In the acidolysis filtering device (2-1), high-purity iron fine powder reacts with concentrated sulfuric acid from a liquid outlet of the sulfuric acid heat exchange device (2-7), ferrous sulfate entering a liquid outlet of the acidolysis heat exchange device (2-6) through a liquid outlet of a cathode chamber of the electric reduction device (3-1) and low-temperature sulfur dioxide at a gas outlet of the sulfur dioxide heat exchanger (2-5) in a reduction acidolysis manner to obtain acidolysis slurry; the sulfuric acid solution is used for starting the system for the first time; filtering acidolysis slurry to obtain acidolysis slag and acid leaching solution; delivering acidolysis slag to the high-temperature desulfurization device (2-3) for treatment; the acid leaching solution is sent to the purification device (2-2) for treatment; in the high-temperature desulfurization device (2-3), gangue, acidolysis slag and purified slag from the purification device (2-2) are subjected to high-temperature desulfurization reaction in the presence of hydrogen to obtain sulfur dioxide gas and cement clinker; delivering and utilizing cement clinker; the sulfur dioxide gas heats air through the sulfur dioxide heat exchanger (2-5), and the heated high-temperature air provides heat required by reaction for acidolysis working procedures and electrometallurgical working procedures respectively; the solar furnace (2-4) converts solar energy into heat energy to generate a high-temperature medium, and the high-temperature medium provides heat for desulfurization reaction through a heat exchange jacket in the high-temperature desulfurization device (2-3); returning the low-temperature medium subjected to heat exchange to the solar furnace; in the purifying device (2-2), the purified ferric sulfate solution is heated by a catholyte heat exchange device (3-4) and then sent to the electro-reduction device (3-1);
In the electroreduction device (3-1), cathode room ferric sulfate is reduced into ferrous sulfate under the action of direct current, when the concentration of sulfuric acid in ferrous sulfate solution is higher than 5g/L, the ferrous sulfate solution is preheated by the acidolysis heat exchange device (2-6) and then is sent into the acidolysis filtering device (2-1); when the concentration of sulfuric acid in the ferrous sulfate solution is lower than 5g/L, the ferrous sulfate solution is fed into the electrometallurgical device (3-2); the solution in the anode chamber of the electro-reduction device (3-1) is separated out of oxygen and generates sulfuric acid under the action of direct current; an oxygen product delivery pipe; mixing 1% -20% of the sulfuric acid solution with the regenerated water generated by the membrane separation device (3-3), circulating to the anolyte heat exchange device (3-5), entering an anolyte inlet of the electro-reduction device (3-1), and delivering the rest sulfuric acid solution into an anode chamber of the electro-metallurgical device (3-2); in the electrometallurgical device (3-2), ferrous sulfate solution from a cathode chamber of the electroreduction device (3-1) and the membrane separation device (3-3) is reduced into pure iron under the action of direct current, hydrogen is produced as a byproduct, and residual dilute ferrous sulfate solution; hydrogen is sent to the fluidization magnetization roasting device (1-1) and the high-temperature desulfurization device (2-3) for utilization or used as a hydrogen product; feeding the dilute ferrous sulfate solution to the membrane separation device (3-3); under the action of direct current, the anode chamber solution of the electrometallurgical device (3-2) separates out oxygen and generates sulfuric acid; an oxygen product delivery pipe; the concentrated sulfuric acid is preheated by the sulfuric acid heat exchange device (2-7) and then is sent into the acidolysis filtering device (2-1).
3. The method for low-carbon electrometallurgical process of iron ore according to claim 2, characterized in that the fluidized-bed reactor is adopted by the fluidized-bed magnetizing roasting device (1-1), green hydrogen is used as a reducing agent, and the solar furnace high-temperature medium provides heat; the reaction temperature is 300-800 ℃, and the residence time is as follows: 5min-30min.
4. The method for low-carbon electrometallurgical process of iron ore according to claim 2, characterized in that the ore dressing device (1-2) obtains high-purity fine iron powder, the iron oxide grade of which is not lower than 94%.
5. The method for low-carbon electrometallurgical process of iron ore according to claim 2, characterized in that in the acidolysis filtering device (2-1), sulfuric acid solution is used for the first start-up of the system, the concentration of concentrated sulfuric acid solution is not lower than 100g/L, and the acidolysis temperature of high-purity fine iron powder is 50-100 ℃;
in the acidolysis filtering device (2-1), ferric ions generated in the acidolysis process are reduced into ferrous ions under the actions of sulfur dioxide chemical reduction and the electric reduction device (3-1) for reducing acidolysis.
6. The method for low-carbon electrometallurgical process of iron ore according to claim 2, characterized in that in the high-temperature desulfurization device (2-3), a fluidized bed or a rotary kiln reactor is adopted, and a solar furnace high-temperature medium is used for providing heat, and the reaction temperature is 1000-1500 ℃.
7. The method for low-carbon electrometallurgical process of iron ore according to claim 2, characterized in that in the electroreduction device (3-1), the membrane material is an ionic membrane or a porous membrane, wherein the permeation rate of the porous membrane is 1% -30%, the electroreduction current density is 50A/m 2-1000A/m2, the anode is a lead alloy or titanium-based ruthenium iridium tantalum coated electrode, the cathode comprises one or more of iron, copper, titanium and stainless steel, and the electroreduction temperature is 20 ℃ -100 ℃.
8. The method for low-carbon electrometallurgical process of iron ore according to claim 2, characterized in that in the electrometallurgical device (3-2), the membrane material is an ionic membrane or a porous membrane, wherein the permeation rate of the porous membrane is 1% -30%, the electroreduction current density is 50A/m 2-1000A/m2, the anode is a lead alloy or titanium-based ruthenium iridium tantalum coated electrode, the cathode comprises one or more of iron, copper, titanium and stainless steel, and the electroreduction temperature is 60 ℃ -100 ℃.
9. The method of low carbon electrometallurgical process of iron ore according to claim 2, characterized in that the membrane separation device (3-3) comprises one or several of reverse osmosis, ultrafiltration, nanofiltration or electrodialysis.
10. The method of low carbon electrometallurgical of iron ore according to claim 2, characterized in that the solar furnace (2-4) converts solar energy into heat energy, the solar heating medium being molten salt and/or gas, the molten salt comprising molten salt composed of one or several of the elements silicon, sodium, oxygen, calcium and aluminum, the gas comprising nitrogen and/or argon.
CN202211412820.2A 2022-10-18 2022-11-11 System and method for low-carbon electrometallurgical of iron ore Pending CN117947262A (en)

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