WO2022042631A1 - 一种熔盐电解综合回收粉煤灰中金属资源的系统及方法 - Google Patents

一种熔盐电解综合回收粉煤灰中金属资源的系统及方法 Download PDF

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WO2022042631A1
WO2022042631A1 PCT/CN2021/114690 CN2021114690W WO2022042631A1 WO 2022042631 A1 WO2022042631 A1 WO 2022042631A1 CN 2021114690 W CN2021114690 W CN 2021114690W WO 2022042631 A1 WO2022042631 A1 WO 2022042631A1
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fly ash
reaction
electrolysis
molten salt
cathode
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PCT/CN2021/114690
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English (en)
French (fr)
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范金航
汪世清
宋润
郭东方
刘练波
郜时旺
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华能国际电力股份有限公司
中国华能集团清洁能源技术研究院有限公司
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Priority to JP2022600126U priority Critical patent/JP3240741U/ja
Priority to DE112021000403.4T priority patent/DE112021000403T5/de
Publication of WO2022042631A1 publication Critical patent/WO2022042631A1/zh
Priority to US18/052,257 priority patent/US20230114074A1/en

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    • 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
    • C25C7/02—Electrodes; Connections thereof
    • C25C7/025—Electrodes; Connections thereof used in cells for the electrolysis of melts
    • 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
    • C25C3/36—Alloys obtained by cathodic reduction of all their ions
    • 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
    • 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
    • C25C7/005—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells of cells for the electrolysis of melts
    • 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
    • Y02P10/20—Recycling

Definitions

  • the application belongs to the field of resource utilization of fly ash, and in particular relates to a system and method for comprehensively recovering metal resources in fly ash by molten salt electrolysis.
  • Fly ash is a mixture of oxides and silicate minerals after burning inorganic minerals in coal, and is a major solid waste produced by coal-fired power plants.
  • the annual increase in power generation, coal as the main energy consumption will inevitably lead to a large increase in the accumulation of fly ash, and the accumulation of fly ash will occupy a large amount of farmland, resulting in a great waste of land resources, and serious pollution of soil and water bodies.
  • the heavy metal elements it contains will also cause great harm to human health. Therefore, it is extremely urgent to develop the technology of harmless treatment and resource utilization of fly ash.
  • fly ash mainly include the manufacture of building materials (cement, concrete, etc.), the synthesis of porous materials, and the extraction of metals.
  • the direct use of fly ash in the manufacture of building materials has the problem that the added value is low and the useful elements it contains cannot be fully utilized.
  • Porous materials synthesized from fly ash, such as zeolite and porous calcium silicate hydrate have certain applications in pollutant treatment and catalyst support, but the overall dosage is small.
  • the main components of fly ash are various oxides, unburned carbon and trace elements.
  • the oxides are mainly composed of Al 2 O 3 , SiO 2 , Fe 2 O 3 , CaO, MgO and TiO 2 , among which Al 2 O3 and SiO2 content is the highest.
  • Metal elements such as Al, Si, and Fe are widely used in economic construction and daily life. Therefore, the effective recovery of metal elements in fly ash is of great significance for the high value-added utilization of fly ash.
  • the research on the recovery and utilization of metal resources in fly ash mainly focuses on the extraction technology of alumina, mainly including limestone sintering method, alkali fusion method, acid dissolution method, acid-base combined method, ammonium sulfate method and other processes.
  • the above process can achieve effective recovery of aluminum resources, it does not fully recover and utilize other metal resources contained in it, such as Si, Fe, Ti, etc.
  • CN 103526234 discloses a system for recycling Al, Si, Ti and Fe resources from fly ash by molten salt electrolysis, but the molten salt used is fluoride salt, which has strong toxicity and corrosiveness.
  • the reaction temperature is Above 900°C, the reaction energy consumption is high. Therefore, the development of a green and low-energy-consumption metal resource comprehensive recovery process system is of great significance for accelerating the resource utilization of fly ash.
  • the present application provides a system and method for comprehensive recovery of metal resources in fly ash by molten salt electrolysis, so as to realize one-step high-efficiency comprehensive recovery and utilization of metal resources in fly ash; Compared with the cryolite system, the toxicity and corrosiveness of the molten salt system are greatly reduced.
  • the technical solution adopted in the present application is, a method for comprehensively recovering metal resources in fly ash by molten salt electrolysis, and decarburizing the fly ash by roasting to obtain decarbonized fly ash;
  • the compression molding raw material is used as the cathode and placed in the electrolyte, and the electrolysis reaction is carried out under an oxygen-free condition; the temperature of the electrolysis reaction is 550°C to 900°C;
  • the cathode reaction product is taken out and cooled to room temperature under an inert atmosphere, and the cooled reaction product is washed to obtain a silicon-aluminum-based alloy.
  • Alumina or silicon oxide is added to the decarburized fly ash.
  • the electrolyte is heated to 100-300° C. at a set heating rate, and vacuumized before electrolysis, and then electrolyzed in an inert gas protective atmosphere.
  • the electrolyte is one or two of calcium chloride, lithium chloride, magnesium chloride, sodium chloride, potassium chloride and barium chloride.
  • the pressure used in the compression molding process is 10-50 MPa.
  • the electrolysis voltage is 2.4V ⁇ 3.6V; when the inert anode is used, the electrolysis voltage is 5V ⁇ 10V; the electrolysis time is 2h ⁇ 24h.
  • a system for comprehensively recovering metal resources in fly ash by molten salt electrolysis includes a roasting furnace, a ball mill, a powder briquetting machine, an electrolysis furnace, a gas distribution device, a vacuum pumping device, a cleaning machine and a dryer; Roasters, ball mills, powder briquetting machines, electrolysis furnaces, washing machines and dryers, electrolysis furnaces are provided with electrolysis cells, the thermocouples of the electrolysis furnaces are set on the outer wall of the electrolysis cells, and the electrolysis furnaces are connected with vacuuming devices and gas distribution devices; electrolysis furnaces A barometer is arranged in the electrolysis furnace, and the opening of the furnace wall of the electrolysis furnace is connected to the reaction anode wiring and the reaction cathode wiring, and the reaction anode wiring and the reaction cathode wiring are connected to the reaction power supply.
  • the reaction power supply adopts DC regulated power supply, and the rated voltage of the DC regulated power supply does not exceed 30V.
  • the vacuuming device includes at least one vacuum pump, the furnace wall of the electrolysis furnace is provided with an air outlet, and the air inlet of the vacuum pump is connected to the air outlet of the electrolysis furnace.
  • the cleaning machine adopts ultrasonic cleaning machine
  • the drying machine adopts vacuum drying machine.
  • the present application at least has the following beneficial effects:
  • the method can realize the efficient and comprehensive recovery and utilization of metal resources in fly ash; the method process is simple, and the alkali metal or alkaline earth metal chloride is used as the molten salt. Compared with the cryolite system, the toxicity and corrosion of the molten salt system are greatly reduced. , the reaction process is safer, the carbon content in fly ash can be effectively reduced by decarburization treatment, the pollution of carbon in electrolysis products can be reduced, and the purity of recovered metals can be improved; ball milling treatment can reduce the amount of fly ash precursor to a certain extent. It is beneficial to accelerate the removal of oxygen in the fly ash and improve the deoxidation rate in the subsequent electrolytic reduction process; the fly ash is pressed into pieces to reduce the size of the fly ash particles and particles. In the electroreduction process, the ohmic polarization between particles is reduced, and the electron transfer efficiency is improved, thereby increasing the deoxidation rate; in addition, the reaction temperature used in this application is relatively low, and the energy consumption is low.
  • the content of elements in the raw material can be adjusted and controlled by introducing metal oxides into the precursor, and the precise control of the element composition in the product and the relative proportion of each component can be realized.
  • the present application provides a system that is configured according to the material flow direction, and some devices have no mandatory connection relationship, so the configuration is more flexible.
  • FIG. 1 is a schematic flowchart of an implementable method of the present application.
  • a method for comprehensive recovery of metal resources in fly ash by molten salt electrolysis comprises the steps:
  • the fly ash is subjected to high temperature roasting for decarburization to obtain decarbonized fly ash;
  • Compression molding is carried out as a cathode, a soluble or insoluble material is used as an anode, and an alkali metal, alkaline earth metal chloride or a mixture thereof is used as the electrolyte;
  • the reaction anode, the pressed reaction cathode and the electrolyte are placed in a special electrolysis system, heated to 100-300°C under the set heating rate, and kept for 6-48 hours to remove the moisture in the electrolyte; use before electrolysis
  • the vacuum pump evacuates the electrolysis system to remove oxygen in the electrolysis system, and then uses a gas distribution device to supplement the inert gas in the electrolysis furnace; under the condition of an inert atmosphere, the electrolysis furnace is heated to the reaction temperature of 550 °C ⁇ 900 °C, and the cathode and anode are heated up.
  • a reaction voltage is applied between and electrolysis is performed;
  • the cathode reaction product is taken out and cooled to room temperature under an inert atmosphere, the cooled reaction product is cleaned to remove the unavoidable electrolyte contained in the reaction product, and the cleaned product is dried to obtain a small amount of electrolyte.
  • the molten salt is washed and filtered, and the obtained filter residue is vacuum-dried to obtain a part of metal aluminum entering the molten salt.
  • the ball milling process adopts dry ball milling or wet ball milling.
  • the liquid used in the wet ball milling process is ethanol.
  • drying treatment is performed, and the added metal oxide is aluminum oxide or silicon oxide.
  • the rated pressure of the powder briquetting machine used in the compression molding process is not less than 50MPa;
  • the pressure used in the compression molding process is 10-50 MPa; the soluble anode is Ca, Mg, Li or C, and the insoluble anode is a metal-based or ceramic-based inert anode.
  • the electrolyte is one or two of calcium chloride, lithium chloride, magnesium chloride, sodium chloride, potassium chloride and barium chloride.
  • a system for comprehensively recovering metal resources in fly ash by molten salt electrolysis includes a roasting furnace, a ball mill, an electric powder briquetting machine, an electrolytic furnace, a gas distribution device, a vacuuming device, a cleaning system and a drying system; A roasting furnace, a ball mill, a powder briquetting machine, an electrolytic furnace cleaning machine and a dryer are set up.
  • An electrolytic cell is set in the electrolytic furnace.
  • the thermocouple in the electrolytic furnace is set on the outer wall of the electrolytic cell.
  • a barometer is arranged in the furnace, and the opening of the furnace wall of the electrolysis furnace is connected to the reaction anode wiring and the reaction cathode wiring, and the reaction anode wiring and the reaction cathode wiring are connected to the reaction power supply.
  • the electrolytic cell adopts graphite crucible or metal oxide crucible.
  • the reaction power supply adopts DC regulated power supply, and the rated voltage of the DC regulated power supply does not exceed 30V.
  • the vacuuming device includes at least one vacuum pump, the furnace wall of the electrolysis furnace is provided with an air outlet, and the air inlet of the vacuum pump is connected to the air outlet of the electrolysis furnace.
  • the gas distribution device adopts an inert gas storage tank, the electrolysis furnace is provided with a gas inlet, and the outlet of the inert gas storage tank is connected to the gas inlet.
  • the gas distribution device adopts an inert gas storage tank, and the output gas of the gas distribution device is high-purity nitrogen or high-purity argon;
  • the cleaning system includes an ultrasonic cleaner and a high-speed centrifuge; the ultrasonic cleaner and the high-speed centrifuge are set along the material flow direction.
  • the cleaning solution used in the ultrasonic cleaning process is deionized water, anhydrous ethanol, dilute hydrochloric acid or dilute sulfuric acid.
  • the dryer adopts a vacuum dryer to prevent the obtained product from being further oxidized.
  • fly ash Weigh the fly ash and put it into a high-temperature resistance furnace for roasting under high temperature conditions to remove the carbon in the fly ash. Place the decarbonized fly ash in a ball milling tank for 12h ball milling at a rotational speed of 300 rpm, and then weigh it. Take 1 g of fly ash powder to carry out compression molding of cathode sheet (20 mm in diameter) under the condition of 10 MPa pressure. The pressed cathode sheet was sintered for 6 hours in an air atmosphere at a temperature of 800°C, and the cathode sheet was contained in a metal basket and fixed to a cathode current collector molybdenum rod with a molybdenum wire.
  • the anode was a graphite rod (20 mm in diameter and 20 cm in length). Put 500g CaCl 2 into the alumina crucible, and place it in the graphite crucible as a whole to prevent the leakage of liquid from damaging the furnace, use the graphite crucible to consume oxygen, control the atmosphere in the reactor, and increase the temperature in the reactor. to 250°C and kept for 48h, and dried with CaCl 2 . Seal the electrolysis furnace, open the vacuum pumping system, vacuum the inside of the electrolysis furnace to eliminate oxygen in the electrolysis system, close the vacuum valve, maintain the negative pressure inside the electrolysis furnace, and supplement the electrolysis furnace with inert gas, repeat 3 times , to maintain a better inert atmosphere inside the electrolysis furnace. Then, under the protection of argon gas and cooling water, the temperature of the reactor was slowly increased to 850°C by a temperature control system at a heating rate of 4°C min ⁇ 1 .
  • the reaction product was transferred to the cleaning system, the cathode sheet was repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), the residual molten salt in the product was removed by an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain a silicon-aluminum-based alloy.
  • the fly ash is weighed and put into a high temperature resistance furnace for roasting under high temperature conditions to remove the carbon in the fly ash.
  • the decarburized fly ash was placed in a ball mill tank for 12h ball milling at a rotational speed of 300rpm.
  • 1 g of fly ash powder was weighed to carry out the compression molding of the cathode sheet (20 mm in diameter) under the condition of 10 MPa pressure.
  • the pressed tablets were fired at 800°C in an air atmosphere for 6 hours. Use a metal basket to hold the cathode sheet and fix it to the cathode current collector molybdenum rod with a molybdenum wire.
  • the reaction electrolyte, the reaction anode and the reaction cathode are placed in the reactor, and the temperature of the reactor is controlled within the range of 550 ⁇ 15°C by the temperature control system.
  • a constant voltage of 3.4V is applied between the reaction anode and the reaction cathode.
  • the cathode sheet is electrolyzed for 20 hours, the cathode sheet is slowly taken out from the top of the reactor.
  • the whole reaction process is under the protection of high-purity argon (purity not less than 99.9%). conduct.
  • the reaction product was transferred to the cleaning system, the cathode sheet was repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), the residual molten salt in the product was removed by an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain a silicon-aluminum-based alloy.
  • fly ash is weighed and put into a high temperature resistance furnace for roasting under high temperature conditions to remove the carbon in the fly ash.
  • the decarburized fly ash was placed in a ball mill tank for 12h ball milling at a rotational speed of 300rpm. Subsequently, 1 g of fly ash powder was weighed to carry out the compression molding of the cathode sheet (20 mm in diameter) under the condition of 10 MPa pressure. Use a metal basket to hold the cathode sheet and fix it to the cathode current collector molybdenum rod with a molybdenum wire.
  • the reaction electrolyte, the reaction anode and the reaction cathode are placed in the reactor, and the temperature of the reactor is controlled by the temperature control system within the range of 700 ⁇ 15°C.
  • a constant voltage of 3.0V was applied between the reaction anode and the reaction cathode.
  • the cathode sheet was electrolyzed for 8 hours, the cathode sheet was slowly taken out from the top of the reactor. The whole reaction process was carried out under the protection of high-purity argon gas.
  • the reaction product was transferred to the cleaning system, the cathode sheet was repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), the residual molten salt in the product was removed by an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain a silicon-aluminum-based alloy.
  • fly ash is weighed and put into a high temperature resistance furnace for roasting under high temperature conditions to remove the carbon in the fly ash.
  • the decarburized fly ash was placed in a ball mill tank for 12h ball milling at a rotational speed of 300rpm. Subsequently, 1 g of fly ash powder was weighed to carry out compression molding of the cathode sheet (20 mm in diameter) under a pressure of 15 MPa. Use a metal basket to hold the cathode sheet and fix it to the cathode current collector molybdenum rod with a molybdenum wire.
  • the reaction electrolyte, the reaction anode and the reaction cathode are placed in the reactor, and the temperature of the reactor is controlled by the temperature control system within the range of 700 ⁇ 15°C.
  • a constant voltage of 3.6V was applied between the reaction anode and the reaction cathode. After the cathode sheet was electrolyzed for 2 hours, the cathode sheet was slowly taken out from the top of the reactor. The entire reaction process was carried out under the protection of high-purity argon gas.
  • the reaction product was transferred to the cleaning system, the cathode sheet was repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), the residual molten salt in the product was removed by an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain a silicon-aluminum-based alloy.
  • fly ash is weighed and put into a high temperature resistance furnace for roasting under high temperature conditions to remove the carbon in the fly ash.
  • the decarburized fly ash was placed in a ball mill tank for 12h ball milling at a rotational speed of 300rpm. Subsequently, 1 g of fly ash powder was weighed to carry out compression molding of the cathode sheet (20 mm in diameter) under the condition of 30 MPa pressure. Use a metal basket to hold the cathode sheet and fix it to the cathode current collector molybdenum rod with a molybdenum wire.
  • the reaction electrolyte, the reaction anode and the reaction cathode are placed in the reactor, and the temperature of the reactor is controlled within the range of 900 ⁇ 15°C by the temperature control system.
  • a constant voltage of 3.0V was applied between the reaction anode and the reaction cathode.
  • the cathode sheet was electrolyzed for 2 hours, the cathode sheet was slowly taken out from the top of the reactor. The whole reaction process was carried out under the protection of high-purity argon gas.
  • the reaction product was transferred to the cleaning system, the cathode sheet was repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), the residual molten salt in the product was removed by an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain a silicon-aluminum-based alloy.
  • fly ash is weighed and put into a high temperature resistance furnace for roasting under high temperature conditions to remove the carbon in the fly ash.
  • the decarburized fly ash was placed in a ball mill tank for 12h ball milling at a rotational speed of 300rpm. Subsequently, 1 g of fly ash powder was weighed and pressed into the cathode sheet (20 mm in diameter) under a pressure of 20 MPa. Use a metal basket to hold the cathode sheet and fix it to the cathode current collector molybdenum rod with a molybdenum wire.
  • the reaction electrolyte, the reaction anode and the reaction cathode are placed in the reactor, and the temperature of the reactor is controlled within the range of 800 ⁇ 15°C by the temperature control system.
  • a constant voltage of 3.0V was applied between the reaction anode and the reaction cathode.
  • the cathode sheet was electrolyzed for 12 hours, the cathode sheet was slowly taken out from the top of the reactor. The entire reaction process was carried out under the protection of high-purity argon gas.
  • the reaction product was transferred to the cleaning system, the cathode sheet was repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), the residual molten salt in the product was removed by an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain a silicon-aluminum-based alloy.
  • fly ash is weighed and put into a high temperature resistance furnace for roasting under high temperature conditions to remove the carbon in the fly ash.
  • the decarburized fly ash was placed in a ball mill tank for 12h ball milling at a rotational speed of 300rpm. Subsequently, 1 g of fly ash powder was weighed to carry out the compression molding of the cathode sheet (20 mm in diameter) under the condition of 10 MPa pressure. Use a metal basket to hold the cathode sheet and fix it to the cathode current collector molybdenum rod with a molybdenum wire.
  • reaction electrolyte, the reaction anode and the reaction cathode are placed in the reactor, and the temperature of the reactor is controlled at 700 ⁇ 15°C by the temperature control system.
  • a constant voltage of 2.4V was applied between the reaction cathode and the cathode sheet was electrolyzed for 24 hours, and then the cathode sheet was slowly taken out from the top of the reactor. The whole reaction process was carried out under the protection of high-purity argon gas.
  • the reaction product was transferred to the cleaning system, the cathode sheet was repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), the residual molten salt in the product was removed by an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain a silicon-aluminum-based alloy.
  • fly ash is weighed and put into a high temperature resistance furnace for roasting under high temperature conditions to remove the carbon in the fly ash.
  • the decarburized fly ash was placed in a ball mill tank for 12h ball milling at a rotational speed of 300rpm. Subsequently, 1 g of fly ash powder was weighed to carry out compression molding of the cathode sheet (20 mm in diameter) under a pressure of 45 MPa. Use a metal basket to hold the cathode sheet and fix it to the cathode current collector molybdenum rod with a molybdenum wire.
  • reaction electrolyte, the reaction anode and the reaction cathode are placed in the reactor, and the temperature of the reactor is controlled at 650 ⁇ 15°C by the temperature control system.
  • a constant voltage of 3.0V was applied between the reaction cathode and the cathode sheet was electrolyzed for 18 hours, and then the cathode sheet was slowly taken out from the top of the reactor. The whole reaction process was carried out under the protection of high-purity argon gas.
  • the reaction product was transferred to the cleaning system, the cathode sheet was repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), the residual molten salt in the product was removed by an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain a silicon-aluminum-based alloy.
  • fly ash is weighed and put into a high temperature resistance furnace for roasting under high temperature conditions to remove the carbon in the fly ash.
  • the decarburized fly ash was placed in a ball mill tank for 12h ball milling at a rotational speed of 300rpm. Subsequently, 1 g of fly ash powder was weighed to carry out the compression molding of the cathode sheet (20 mm in diameter) under the condition of 10 MPa pressure. Use a metal basket to hold the cathode sheet and fix it to the cathode current collector molybdenum rod with a molybdenum wire.
  • reaction electrolyte, the reaction anode and the reaction cathode are placed in the reactor, and the temperature of the reactor is controlled at 900 ⁇ 15°C by the temperature control system.
  • a constant voltage of 2.4V was applied between the reaction cathode and the cathode sheet was electrolyzed for 5 hours, and then the cathode sheet was slowly taken out from the top of the reactor. The whole reaction process was carried out under the protection of high-purity argon gas.
  • the reaction product was transferred to the cleaning system, the cathode sheet was repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), the residual molten salt in the product was removed by an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain a silicon-aluminum-based alloy.
  • the fly ash and alumina after decarburization were weighed and put into a ball mill tank for 12h ball milling at a rotational speed of 300 rpm. Subsequently, 1 g of the mixed precursor powder was weighed to carry out compression molding of a cathode sheet (20 mm in diameter) under a pressure of 30 MPa. The pressed sheet was sintered for 6 hours in an air atmosphere at a temperature of 800°C, and the cathode sheet was contained in a metal basket and fixed to a cathode current collector molybdenum rod with a molybdenum wire.
  • the reaction electrolyte, the reaction anode and the reaction cathode are placed in the reactor, the temperature of the reactor is controlled by the temperature control system to be 750 ⁇ 15°C, and the reaction voltage is controlled by the reaction control system to be 2.8 V. After 8 hours of electrolysis on the sheet, the cathode sheet was slowly taken out, and the whole reaction process was carried out under the protection of high-purity argon gas.
  • the reaction product was transferred to a cleaning system, the tablets were repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), and the residual molten salt in the product was removed using an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain silicon-aluminum-based alloys with different aluminum contents.
  • the fly ash and alumina after decarburization were weighed and put into a ball mill tank for 12h ball milling at a rotational speed of 300 rpm. Subsequently, 1 g of the mixed precursor powder was weighed to carry out compression molding of a cathode sheet (20 mm in diameter) under a pressure of 10 MPa. Use a metal basket to hold the cathode sheet and fix it to the cathode current collector molybdenum rod with a molybdenum wire.
  • the reaction electrolyte, the reaction anode and the reaction cathode are placed in the reactor, the temperature of the reactor is controlled by the temperature control system to be 850 ⁇ 15°C, and the reaction voltage is controlled by the reaction control system to be 3.0 V. After 10 hours of electrolysis on the sheet, the cathode sheet is slowly taken out, and the whole reaction process is carried out under the protection of high-purity argon gas.
  • the reaction product was transferred to a cleaning system, the tablets were repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), and the residual molten salt in the product was removed using an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain silicon-aluminum-based alloys with different aluminum contents.
  • Adding alumina to fly ash can effectively control the aluminum content in the product.
  • the fly ash and silicon oxide were weighed and put into a ball-milling jar for 12h ball-milling at a rotational speed of 300rpm. Subsequently, 1 g of the mixed precursor powder was weighed to carry out compression molding of a cathode sheet (20 mm in diameter) under a pressure of 10 MPa. The pressed sheet was sintered for 6 hours in an air atmosphere at a temperature of 800°C, and the cathode sheet was contained in a metal basket and fixed to a cathode current collector molybdenum rod with a molybdenum wire.
  • the reaction electrolyte, the reaction anode and the reaction cathode are placed in the reactor, the temperature of the reactor is controlled by the temperature control system to be 850 ⁇ 15°C, and the reaction voltage is controlled by the reaction control system to be 3.0 V. After electrolyzing the sheet for 20 hours, the cathode sheet was slowly taken out, and the whole reaction process was carried out under the protection of high-purity argon gas.
  • the reaction product was transferred to a cleaning system, the tablets were repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), and the residual molten salt in the product was removed using an ultrasonic cleaner, and the reaction product was centrifuged.
  • the centrifuged product was transferred to a drying system and dried in vacuum at 80°C for 2 hours to obtain silicon-aluminum-based alloys with different silicon contents.
  • Adding silicon oxide to fly ash can effectively control the silicon content in the product.
  • the fly ash is weighed and put into a high temperature resistance furnace for roasting under high temperature conditions to remove the carbon in the fly ash.
  • the decarburized fly ash was placed in a ball mill tank for 12h ball milling at a rotational speed of 300rpm.
  • 1 g of fly ash powder was weighed to carry out compression molding of the cathode sheet (20 mm in diameter) under a pressure of 50 MPa.
  • the pressed tablets were fired at 800°C in an air atmosphere for 6 hours. Use a metal basket to hold the cathode sheet and fix it to the cathode current collector molybdenum rod with a molybdenum wire.
  • the reaction product was transferred to the cleaning system, the cathode sheet was repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), the residual molten salt in the product was removed by an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain a silicon-aluminum-based alloy.
  • fly ash is weighed and put into a high temperature resistance furnace for roasting under high temperature conditions to remove the carbon in the fly ash.
  • the decarburized fly ash was placed in a ball mill tank for 12h ball milling at a rotational speed of 300rpm. Subsequently, 1 g of fly ash powder was weighed to carry out the compression molding of the cathode sheet (20 mm in diameter) under the condition of 10 MPa pressure. Use a metal basket to hold the cathode sheet and fix it to the cathode current collector molybdenum rod with a molybdenum wire.
  • the reaction electrolyte, inert anode and reaction cathode are placed in the reactor, and the temperature of the reactor is controlled within the range of 900 ⁇ 15°C by the temperature control system , through the reaction control system, a constant voltage of 5V is applied between the reaction anode and the reaction cathode. After the cathode sheet is electrolyzed for 20 hours, the cathode sheet is slowly taken out from the top of the reactor. The whole reaction process is carried out under the protection of high-purity argon gas.
  • the reaction product was transferred to the cleaning system, the cathode sheet was repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), the residual molten salt in the product was removed by an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain a silicon-aluminum-based alloy.
  • fly ash is weighed and put into a high temperature resistance furnace for roasting under high temperature conditions to remove the carbon in the fly ash.
  • the decarburized fly ash was placed in a ball mill tank for 12h ball milling at a rotational speed of 300rpm. Subsequently, 1 g of fly ash powder was weighed to carry out the compression molding of the cathode sheet (20 mm in diameter) under the condition of 10 MPa pressure.
  • a metal basket is used to hold the cathode sheet and molybdenum wire is used to fix it on the cathode current collector molybdenum rod;
  • CaCl 2 -NaCl is used as the electrolyte, and a stable metal base or ceramic base material is used as the anode, and the reaction electrolyte, the inert anode and the reaction cathode are placed in the In the reactor, the temperature of the reactor is controlled within the range of 900 ⁇ 15°C by the temperature control system, and a constant voltage of 7.5V is applied between the reaction anode and the reaction cathode through the reaction control system. The top of the reactor was taken out slowly, and the whole reaction process was carried out under the protection of high-purity argon.
  • the reaction product was transferred to the cleaning system, the cathode sheet was repeatedly soaked with deionized water and dilute hydrochloric acid (0.1M), the residual molten salt in the product was removed by an ultrasonic cleaner, and the reaction product was centrifuged. The centrifuged product was transferred to a drying system and vacuum-dried at 80°C for 2 hours to obtain a silicon-aluminum-based alloy.

Abstract

本申请公开了一种熔盐电解综合回收粉煤灰中金属资源的系统及方法，方法具体为将粉煤灰焙烧进行脱碳处理；将除碳的粉煤灰进行球磨，得到粒径分布均匀的粉煤灰；再将粒径分布均匀的粉煤灰压制成型原料作为阴极并置于电解质中，在无氧条件下进行电解反应；电解反应温度为550℃～900℃；电解反应结束后，将阴极反应产物提出并在惰性气氛下冷却至室温，将冷却后的反应产物清洗后得到硅铝基合金；本方法能实现粉煤灰中金属资源的一步高效综合回收利用；方法过程简单，且以碱金属或碱土金属氯化物为熔盐，相比于冰晶石体系，熔盐体系毒性及腐蚀性均大幅降低，反应温度较低，能耗低，所述系统只需按照物料流向进行配置，无强制连接关系，更加灵活。

Description

一种熔盐电解综合回收粉煤灰中金属资源的系统及方法 技术领域
本申请属于粉煤灰资源化利用领域，具体涉及一种熔盐电解综合回收粉煤灰中金属资源的系统及方法。
背景技术
粉煤灰是煤中无机矿物质灼烧后的氧化物和硅酸盐矿物组成的混合物，是燃煤电厂产生的一种主要固体废弃物。发电量的逐年增加，煤炭作为主体消耗能源将不可避免的导致粉煤灰的堆积量大量增加，粉煤灰的堆积将占据大量农田，造成土地资源的极大浪费，同时严重污染土壤及水体，所含的重金属元素也会对人体健康造成极大危害。因此，发展粉煤灰的无害化处理及资源化利用技术极为迫切。
目前针对粉煤灰的利用技术主要包括制造建筑材料(水泥、混凝土等)、合成多孔材料和提取金属等。粉煤灰直接用于制造建筑材料存在附加值低，所含有用元素并不能被充分利用的问题。利用粉煤灰合成的多孔材料如沸石、多孔水化硅酸钙等虽然在污染物处理及催化剂载体方面有一定应用，但总体用量较小。粉煤灰的主要成分为各种氧化物、未燃尽的碳和微量元素，氧化物主要由Al 2O 3、SiO 2、Fe 2O 3、CaO、MgO和TiO 2等组成，其中Al 2O 3和SiO 2含量最高。金属元素Al、Si、Fe等在经济建设及日常生活中广泛使用，因此将粉煤灰中金属元素进行有效回收对于粉煤灰的高附加值利用具有重要意义。
目前对于粉煤灰中金属资源的回收利用研究主要集中在氧化铝的提取技术方面，主要有石灰石烧结法、碱熔法、酸溶法、酸碱联合法、硫酸铵法等工艺。上述工艺虽可实现铝资源的有效回收，但并未对所含其他金属资源如Si、Fe、Ti等进行充分回收利用。CN 103526234公开了一种熔盐电解法处理粉煤灰回收Al、Si、Ti和Fe资源的系统，但所采用熔盐为氟化盐，具 有较强的毒性和腐蚀性，此外，反应温度在900℃以上，导致反应能耗较高。因此，发展一种绿色低能耗的金属资源综合回收工艺系统对于加速粉煤灰的资源化利用具有重要意义。
发明内容
为了解决现有技术中存在的问题，本申请提供一种熔盐电解综合回收粉煤灰中金属资源的系统及方法，实现粉煤灰中金属资源的一步高效综合回收利用；方法过程简单，相比于冰晶石体系，熔盐体系毒性及腐蚀性均大幅降低。
为了实现上述目的，本申请采用的技术方案是，一种熔盐电解综合回收粉煤灰中金属资源的方法，将粉煤灰焙烧进行脱碳处理，得到除碳的粉煤灰；
将除碳的粉煤灰进行球磨，得到粒径分布均匀的粉煤灰；
将所述粒径分布均匀的粉煤灰压制成型；
将压制成型原料作为阴极并置于电解质中，在无氧条件下进行电解反应；电解反应温度为550℃～900℃；
电解反应结束后，将阴极反应产物提出并在惰性气氛下冷却至室温，将冷却后的反应产物清洗后得到硅铝基合金。
所述脱碳粉煤灰中添加氧化铝或氧化硅。
将电解质以设定的升温速率加热至100～300℃保温，电解前抽真空，然后在惰性气体保护气氛下电解。
电解质为氯化钙、氯化锂、氯化镁、氯化钠、氯化钾和氯化钡中的一种或两种。
压制成型过程中所采用压力为10～50MPa。
石墨棒做阳极时，电解电压为2.4V～3.6V；使用惰性阳极时，电解电压为5V～10V；电解时间为2h～24h。
一种熔盐电解综合回收粉煤灰中金属资源的系统，包括焙烧炉、球磨机、粉末压块机，电解炉、配气装置、抽真空装置、清洗机以及干燥机；沿着物料流向依次设置焙烧炉、球磨机、粉末压块机、电解炉、清洗机和干燥机，电解炉中设置电解池，电解炉的热电偶设置在电解池外壁，电解炉连接抽真空装置和配气装置；电解炉中设置有气压计，电解炉的炉壁开孔通入反应阳极接线和反应阴极接线，反应阳极接线和反应阴极接线连接反应电源。
反应电源采用直流稳压电源，直流稳压电源的额定电压不超过30V。
抽真空装置包括至少一台真空泵，电解炉的炉壁开设出气口，真空泵的进气口连通电解炉的出气口。
清洗机采用超声清洗机，干燥机采用真空干燥机。
与现有技术相比，本申请至少具有以下有益效果：
本方法能实现粉煤灰中金属资源的高效综合回收利用；方法过程简单，且以碱金属或碱土金属氯化物为熔盐，相比于冰晶石体系，熔盐体系毒性及腐蚀性均大幅降低，反应过程更加安全，通过脱碳处理可有效降低粉煤灰中碳含量，减少电解产物中碳的污染问题，提高所回收金属的纯度；球磨处理可在一定程度上减小粉煤灰前驱体的粒径，并使其粒径均匀化，有利于在后续的电解还原过程中加快粉煤灰中氧的脱除，提高脱氧速率；将粉煤灰压制成片，缩小粉煤灰颗粒与颗粒之间的间隙，在电解还原过程中减小颗粒之间的欧姆极化，提高电子传递效率，从而提高脱氧速率；此外，本申请所采用的反应温度相对较低，能耗低。
进一步的，通过前驱体中引入金属氧化物可以调节控制原料中元素的含量，可实现产物中元素组成及各组分相对比例的精确调控。
本申请提供一种所述系统按照物料流向进行配置，部分设备无强制连接关系，配置更加灵活。
附图说明
图1为本申请一种可实施方法流程示意图。
具体实施方式
下面结合具体实施例及附图对本申请进行详细解释。
参考图1，一种熔盐电解综合回收粉煤灰中金属资源的方法，包括如下步骤：
将粉煤灰经过高温焙烧进行脱碳处理，以得到除碳后的粉煤灰；
将脱碳后的粉煤灰转移至球磨系统进行球磨，以减小其粒径并使其均匀化，以球磨后的粉煤灰或添加金属氧化物的粉煤灰为原料，在加压条件下进行压制成型作为阴极，以可溶或不可溶材料作为阳极，以碱金属、碱土金属氯化物或其混合物为电解质；
将反应阳极、压制成型的反应阴极和电解质放置于特殊的电解系统中，在设定的升温速率条件下加热至100～300℃，保温6～48h，以脱除电解质中的水分；电解前使用真空泵对电解系统进行抽真空处理以去除电解系统中的氧气，随后使用配气装置对电解炉中补充惰性气体；在惰性气氛条件下将电解炉升温至反应温度550℃～900℃，在阴阳极之间施加反应电压并进行电解；
待电解反应结束后，将阴极反应产物提出并在惰性气氛下冷却至室温，将冷却后的反应产物进行清洗以去除反应产物中所含不可避免的电解质，对清洗后的产物进行干燥得到含有少量铁和钛元素的硅铝基合金；
同时，将熔盐进行水洗和过滤，所得滤渣进行真空干燥得到部分进入熔盐的金属铝。
球磨过程采用干式球磨或湿式球磨，湿式球磨过程所采用的液体为乙醇，湿式球磨完成后，进行烘干处理，所添加金属氧化物为氧化铝或氧化硅。
压制成型过程中所采用的粉末压块机的额定压力不低于50MPa；
压制成型过程中所采用压力为10～50MPa；可溶阳极为Ca、Mg、Li或C，不可溶阳极为金属基或陶瓷基惰性阳极。
电解质为氯化钙、氯化锂、氯化镁、氯化钠、氯化钾和氯化钡中的一种或两种。
一种熔盐电解综合回收粉煤灰中金属资源的系统，包括焙烧炉、球磨机、电粉末压块机，电解炉、配气装置、抽真空装置、清洗系统以及干燥系统；沿着物料流向依次设置焙烧炉、球磨机、粉末压块机、电解炉清洗机和干燥机，电解炉中设置电解池，电解炉中的热电偶设置在电解池外壁，电解炉连接抽真空装置和配气装置；电解炉中设置有气压计，电解炉的炉壁开孔通入反应阳极接线和反应阴极接线，反应阳极接线和反应阴极接线连接反应电源。
电解池采用石墨坩埚或金属氧化物坩埚。
反应电源采用直流稳压电源，直流稳压电源的额定电压不超过30V。
抽真空装置包括至少一台真空泵，电解炉的炉壁开设出气口，真空泵的进气口连通电解炉的出气口。
配气装置采用惰性气体存储罐，电解炉开设气体入口，惰性气体存储罐的出口连通所述气体入口。
配气装置采用惰性气体存储罐，配气装置所输出气体为高纯氮气或高纯氩气；
清洗系统包括超声波清洗机和高速离心机；超声波清洗机和高速离心机沿物料流向设置。超声波清洗过程所采用清洗溶液为去离子水、无水乙醇、稀盐酸或稀硫酸。
干燥机采用真空干燥机，防止所得产物进一步被氧化。
实施例1
称取粉煤灰放入高温电阻炉内在高温条件下进行焙烧，去除粉煤灰中的碳，将脱碳后的粉煤灰置于球磨罐中在转速为300rpm条件下进行12h球磨，随后称取1g粉煤灰粉末在10MPa压力条件下进行阴极片(直径为20mm)的压制成型。将压制成型的阴极片在温度为800℃空气气氛条件下烧结6h，用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。阳极为石墨棒(直径为20mm，长度为20cm)。将500gCaCl 2放入氧化铝坩埚中，并整体置于石墨坩埚中以 防止漏液对炉膛的损伤，使用石墨坩埚可以消耗氧气，对反应器中的气氛进行控制，使反应器内的温度升高到250℃并保温48h，对CaCl 2进行烘干处理。将电解炉进行密封，打开真空抽气系统，对电解炉内部进行抽真空处理，以消除电解系统内部氧气，关闭真空阀，保持电解炉内部负压状态，对电解炉补充惰性气体，反复3次，保持电解炉内部较好的惰性气氛。随后在氩气条件及冷却水的保护下，通过温度控制系统以4℃min -1的升温速率将反应器温度缓慢升高到850℃。
以石墨棒为阳极，泡沫镍为阴极，在2.5V恒压条件下对CaCl 2熔盐进行12h预电解以去除电解质中残留的杂质。待反应电流达到稳定后，将阴极泡沫镍从反应器顶部取出并换为反应所需的阴极片。在3.0V电压下对阴极片进行18h电解后，将阴极片取出炉膛。整个反应过程均在高纯氩气保护下进行。将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对阴极片进行反复浸泡，使用超声波清洗机去除产品中残留的熔盐，并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到硅铝基合金。
实施例2
称取粉煤灰放入高温电阻炉内在高温条件下进行焙烧，去除粉煤灰中的碳。将脱碳后的粉煤灰置于球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g粉煤灰粉末在10MPa压力条件下进行阴极片(直径为20mm)的压制成型。将压制成型的片在温度为800℃空气气氛条件下焙烧6h。用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。以CaCl 2-NaCl为电解质，以石墨棒为阳极，将反应电解质、反应阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度在550±15℃范围内，通过反应控制系统在反应阳极与反应阴极之间施加3.4V恒定电压，对阴极片进行20h电解后，将阴极片从反应器顶部缓慢取出，整个反应过程均在高纯氩气(纯度不低于99.9％)保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对阴极片进行反复浸泡，使用超声波清洗机去除产品中残留的熔盐， 并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到硅铝基合金。
实施例3
称取粉煤灰放入高温电阻炉内在高温条件下进行焙烧，去除粉煤灰中的碳。将脱碳后的粉煤灰置于球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g粉煤灰粉末在10MPa压力条件下进行阴极片(直径为20mm)的压制成型。用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。以CaCl 2-NaCl为电解质，以石墨棒为阳极，将反应电解质、反应阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度在700±15℃范围内，通过反应控制系统在反应阳极与反应阴极之间施加3.0V恒定电压，对阴极片进行8h电解后，将阴极片从反应器顶部缓慢取出，整个反应过程均在高纯氩气保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对阴极片进行反复浸泡，使用超声波清洗机去除产品中残留的熔盐，并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到硅铝基合金。
实施例4
称取粉煤灰放入高温电阻炉内在高温条件下进行焙烧，去除粉煤灰中的碳。将脱碳后的粉煤灰置于球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g粉煤灰粉末在15MPa压力条件下进行阴极片(直径为20mm)的压制成型。用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。以CaCl 2-NaCl为电解质，以石墨棒为阳极，将反应电解质、反应阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度在700±15℃范围内，通过反应控制系统在反应阳极与反应阴极之间施加3.6V恒定电压，对阴极片进行2h电解后，将阴极片从反应器顶部缓慢取出，整个反应过程均在高纯氩气保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对阴极片进行反复浸泡，使用超声波清洗机去除产品 中残留的熔盐，并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到硅铝基合金。
实施例5
称取粉煤灰放入高温电阻炉内在高温条件下进行焙烧，去除粉煤灰中的碳。将脱碳后的粉煤灰置于球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g粉煤灰粉末在30MPa压力条件下进行阴极片(直径为20mm)的压制成型。用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。以CaCl 2-NaCl为电解质，以石墨棒为阳极，将反应电解质、反应阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度在900±15℃范围内，通过反应控制系统在反应阳极与反应阴极之间施加3.0V恒定电压，对阴极片进行2h电解后，将阴极片从反应器顶部缓慢取出，整个反应过程均在高纯氩气保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对阴极片进行反复浸泡，使用超声波清洗机去除产品中残留的熔盐，并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到硅铝基合金。
实施例6
称取粉煤灰放入高温电阻炉内在高温条件下进行焙烧，去除粉煤灰中的碳。将脱碳后的粉煤灰置于球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g粉煤灰粉末在20MPa压力条件下进行阴极片(直径为20mm)的压制成型。用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。以CaCl 2-NaCl为电解质，以石墨棒为阳极，将反应电解质、反应阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度在800±15℃范围内，通过反应控制系统在反应阳极与反应阴极之间施加3.0V恒定电压，对阴极片进行12h电解后，将阴极片从反应器顶部缓慢取出，整个反应过程均在高纯氩气保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对阴极片进行反复浸泡，使用超声波清洗机去除产 品中残留的熔盐，并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到硅铝基合金。
实施例7
称取粉煤灰放入高温电阻炉内在高温条件下进行焙烧，去除粉煤灰中的碳。将脱碳后的粉煤灰置于球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g粉煤灰粉末在10MPa压力条件下进行阴极片(直径为20mm)的压制成型。用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。以CaCl 2-NaCl为电解质，以石墨棒为阳极，将反应电解质、反应阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度在700±15℃，通过反应控制系统在反应阳极与反应阴极之间施加2.4V恒定电压，对阴极片进行24h电解后，将阴极片从反应器顶部缓慢取出，整个反应过程均在高纯氩气保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对阴极片进行反复浸泡，使用超声波清洗机去除产品中残留的熔盐，并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到硅铝基合金。
实施例8
称取粉煤灰放入高温电阻炉内在高温条件下进行焙烧，去除粉煤灰中的碳。将脱碳后的粉煤灰置于球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g粉煤灰粉末在45MPa压力条件下进行阴极片(直径为20mm)的压制成型。用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。以CaCl 2-NaCl为电解质，以石墨棒为阳极，将反应电解质、反应阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度在650±15℃，通过反应控制系统在反应阳极与反应阴极之间施加3.0V恒定电压，对阴极片进行18h电解后，将阴极片从反应器顶部缓慢取出，整个反应过程均在高纯氩气保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对阴极片进行反复浸泡，使用超声波清洗机去除产品中残 留的熔盐，并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到硅铝基合金。
实施例9
称取粉煤灰放入高温电阻炉内在高温条件下进行焙烧，去除粉煤灰中的碳。将脱碳后的粉煤灰置于球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g粉煤灰粉末在10MPa压力条件下进行阴极片(直径为20mm)的压制成型。用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。以CaCl 2-NaCl为电解质，以石墨棒为阳极，将反应电解质、反应阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度在900±15℃，通过反应控制系统在反应阳极与反应阴极之间施加2.4V恒定电压，对阴极片进行5h电解后，将阴极片从反应器顶部缓慢取出，整个反应过程均在高纯氩气保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对阴极片进行反复浸泡，使用超声波清洗机去除产品中残留的熔盐，并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到硅铝基合金。
实施例10
称取脱碳后粉煤灰和氧化铝放入球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g混合前驱体粉末在30MPa压力条件下进行阴极片(直径为20mm)的压制成型。将压制成型的片在温度为800℃空气气氛条件下烧结6h，用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。以CaCl 2为电解质，以石墨棒为阳极，将反应电解质、反应阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度为750±15℃，通过反应控制系统控制反应电压为2.8V，对片进行8h电解后，将阴极片缓慢取出，整个反应过程均在高纯氩气保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对片进行反复浸泡，使用超声波清洗机去除产品中残留的熔盐，并对反应产物进行离心。将离心后的产物转移至干 燥系统在80℃条件下真空干燥2h，便可得到不同铝含量的硅铝基合金。
实施例11
称取脱碳后粉煤灰和氧化铝放入球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g混合前驱体粉末在10MPa压力条件下进行阴极片(直径为20mm)的压制成型。用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。以CaCl 2为电解质，以石墨棒为阳极，将反应电解质、反应阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度为850±15℃，通过反应控制系统控制反应电压为3.0V，对片进行10h电解后，将阴极片缓慢取出，整个反应过程均在高纯氩气保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对片进行反复浸泡，使用超声波清洗机去除产品中残留的熔盐，并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到不同铝含量的硅铝基合金。
粉煤灰中加入氧化铝，能有效控制产物中铝含量。
实施例12
称取粉煤灰和氧化硅放入球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g混合前驱体粉末在10MPa压力条件下进行阴极片(直径为20mm)的压制成型。将压制成型的片在温度为800℃空气气氛条件下烧结6h，用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。以CaCl 2为电解质，以石墨棒为阳极，将反应电解质、反应阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度为850±15℃，通过反应控制系统控制反应电压为3.0V，对片进行20h电解后，将阴极片缓慢取出，整个反应过程均在高纯氩气保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对片进行反复浸泡，使用超声波清洗机去除产品中残留的熔盐，并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到不同硅含量的硅铝基合金。
粉煤灰中加入氧化硅，能有效控制产物中硅含量。
实施例13
称取粉煤灰放入高温电阻炉内在高温条件下进行焙烧，去除粉煤灰中的碳。将脱碳后的粉煤灰置于球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g粉煤灰粉末在50MPa压力条件下进行阴极片(直径为20mm)的压制成型。将压制成型的片在温度为800℃空气气氛条件下焙烧6h。用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。以CaCl 2-NaCl为电解质，采用稳定的金属或陶瓷材料为惰性阳极，将反应电解质、惰性阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度在800±15℃范围内，通过反应控制系统在反应阳极与反应阴极之间施加10V恒定电压，对阴极片进行24h电解后，将阴极片从反应器顶部缓慢取出，整个反应过程均在高纯氩气保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对阴极片进行反复浸泡，使用超声波清洗机去除产品中残留的熔盐，并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到硅铝基合金。
实施例14
称取粉煤灰放入高温电阻炉内在高温条件下进行焙烧，去除粉煤灰中的碳。将脱碳后的粉煤灰置于球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g粉煤灰粉末在10MPa压力条件下进行阴极片(直径为20mm)的压制成型。用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒。以CaCl 2-NaCl为电解质，以稳定的金属基或陶瓷基材料为阳极，将反应电解质、惰性阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度在900±15℃范围内，通过反应控制系统在反应阳极与反应阴极之间施加5V恒定电压，对阴极片进行20h电解后，将阴极片从反应器顶部缓慢取出，整个反应过程均在高纯氩气保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对阴极片进行反复浸泡，使用超 声波清洗机去除产品中残留的熔盐，并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到硅铝基合金。
实施例15
称取粉煤灰放入高温电阻炉内在高温条件下进行焙烧，去除粉煤灰中的碳。将脱碳后的粉煤灰置于球磨罐中在转速为300rpm条件下进行12h球磨。随后称取1g粉煤灰粉末在10MPa压力条件下进行阴极片(直径为20mm)的压制成型。用金属篮盛装阴极片并用钼丝将其固定于阴极集流体钼棒；以CaCl 2-NaCl为电解质，以稳定的金属基或陶瓷基材料为阳极，将反应电解质、惰性阳极、反应阴极置于反应器内，通过温度控制系统控制反应器温度在900±15℃范围内，通过反应控制系统在反应阳极与反应阴极之间施加7.5V恒定电压，对阴极片进行22h电解后，将阴极片从反应器顶部缓慢取出，整个反应过程均在高纯氩气保护下进行。待完全冷却后，将反应产物转移至清洗系统，用去离子水和稀盐酸(0.1M)对阴极片进行反复浸泡，使用超声波清洗机去除产品中残留的熔盐，并对反应产物进行离心。将离心后的产物转移至干燥系统在80℃条件下真空干燥2h，便可得到硅铝基合金。

Claims (10)

  1. 一种熔盐电解综合回收粉煤灰中金属资源的方法，其特征在于，
    将粉煤灰焙烧进行脱碳处理，得到除碳的粉煤灰；
    将除碳的粉煤灰进行球磨，得到粒径分布均匀的粉煤灰；
    将所述粒径分布均匀的粉煤灰压制成型；
    将压制成型原料作为阴极并置于电解质中，在无氧条件下进行电解反应；电解反应温度为550℃～900℃；
    电解反应结束后，将阴极反应产物提出并在惰性气氛下冷却至室温，将冷却后的反应产物清洗后得到硅铝基合金。
  2. 根据权利要求1所述的熔盐电解综合回收粉煤灰中金属资源的方法，其特征在于，所述脱碳粉煤灰中添加氧化铝或氧化硅。
  3. 根据权利要求1所述的熔盐电解综合回收粉煤灰中金属资源的方法，其特征在于，将电解质以设定的升温速率加热至100～300℃保温，电解前抽真空，然后在惰性气体保护气氛下电解。
  4. 根据权利要求1所述的熔盐电解综合回收粉煤灰中金属资源的方法，其特征在于，电解质为氯化钙、氯化锂、氯化镁、氯化钠、氯化钾和氯化钡中的一种或两种。
  5. 根据权利要求1所述的熔盐电解综合回收粉煤灰中金属资源的方法，其特征在于，压制成型过程中所采用压力为10～50MPa。
  6. 根据权利要求1所述的熔盐电解综合回收粉煤灰中金属资源的方法，其特征在于，使用石墨棒做阳极时，电解电压为2.4V～3.6V；使用惰性阳极时，电解电压为5V～10V；电解时间为2h～24h。
  7. 一种熔盐电解综合回收粉煤灰中金属资源的系统，其特征在于，包括焙烧炉、球磨机、粉末压块机，电解炉、配气装置、抽真空装置、清洗机以及干燥机；沿着物料流向依次设置焙 烧炉、球磨机、粉末压块机、电解炉、清洗机和干燥机，电解炉中设置电解池，电解炉的热电偶设置在电解池外壁，电解炉连接抽真空装置和配气装置；电解炉中设置有气压计，电解炉的炉壁开孔通入反应阳极接线和反应阴极接线，反应阳极接线和反应阴极接线连接反应电源。
  8. 根据权利要求1所述的熔盐电解综合回收粉煤灰中金属资源的系统，其特征在于，反应电源采用直流稳压电源，直流稳压电源的额定电压不超过30V。
  9. 根据权利要求7所述的熔盐电解综合回收粉煤灰中金属资源的系统，其特征在于，抽真空装置包括至少一台真空泵，电解炉的炉壁开设出气口，真空泵的进气口连通电解炉的出气口。
  10. 根据权利要求7所述的熔盐电解综合回收粉煤灰中金属资源的系统，其特征在于，清洗机采用超声清洗机，干燥机采用真空干燥机。
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