WO2023157826A1 - 亜鉛回収方法 - Google Patents

亜鉛回収方法 Download PDF

Info

Publication number
WO2023157826A1
WO2023157826A1 PCT/JP2023/004931 JP2023004931W WO2023157826A1 WO 2023157826 A1 WO2023157826 A1 WO 2023157826A1 JP 2023004931 W JP2023004931 W JP 2023004931W WO 2023157826 A1 WO2023157826 A1 WO 2023157826A1
Authority
WO
WIPO (PCT)
Prior art keywords
zinc
aqueous solution
sodium hydroxide
component
containing aqueous
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2023/004931
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
憲治 拝生
宏行 松浦
和彦 元場
咲子 朝長
芳恵 玉井
修司 母里
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
KINOTECH Corp
University of Tokyo NUC
Original Assignee
KINOTECH Corp
University of Tokyo NUC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by KINOTECH Corp, University of Tokyo NUC filed Critical KINOTECH Corp
Priority to EP23756351.5A priority Critical patent/EP4481072A4/en
Priority to JP2024501376A priority patent/JP7756379B2/ja
Priority to US18/836,436 priority patent/US20250154676A1/en
Priority to CN202380020367.7A priority patent/CN118660980A/zh
Publication of WO2023157826A1 publication Critical patent/WO2023157826A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B19/00—Obtaining zinc or zinc oxide
    • C22B19/30—Obtaining zinc or zinc oxide from metallic residues or scraps
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C1/00—Electrolytic production, recovery or refining of metals by electrolysis of solutions
    • C25C1/16—Electrolytic production, recovery or refining of metals by electrolysis of solutions of zinc, cadmium or mercury
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B1/00—Preliminary treatment of ores or scrap
    • C22B1/005—Preliminary treatment of scrap
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B1/00—Preliminary treatment of ores or scrap
    • C22B1/02—Roasting processes
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
    • C22B3/04—Extraction of metal compounds from ores or concentrates by wet processes by leaching
    • C22B3/12—Extraction of metal compounds from ores or concentrates by wet processes by leaching in inorganic alkaline solutions
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
    • C22B3/20—Treatment or purification of solutions, e.g. obtained by leaching
    • C22B3/22—Treatment or purification of solutions, e.g. obtained by leaching by physical processes, e.g. by filtration, by magnetic means, or by thermal decomposition
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
    • C22B3/20—Treatment or purification of solutions, e.g. obtained by leaching
    • C22B3/44—Treatment or purification of solutions, e.g. obtained by leaching by chemical processes
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B3/00—Extraction of metal compounds from ores or concentrates by wet processes
    • C22B3/20—Treatment or purification of solutions, e.g. obtained by leaching
    • C22B3/44—Treatment or purification of solutions, e.g. obtained by leaching by chemical processes
    • C22B3/46—Treatment or purification of solutions, e.g. obtained by leaching by chemical processes by substitution, e.g. by cementation
    • 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 present invention relates to a zinc recovery method, and in particular, in addition to electric furnace dust generated during scrap melting and smelting in the electric furnace method, which is one of the ironmaking processes, blast furnace dust, blast furnace/converter dust, or RHF (Rotary Hearth Furnace: rotating It relates to a method for recovering zinc using primary or secondary dust such as hearth furnace dust or zinc-containing dust such as calcination of zinc concentrate as a raw material.
  • primary or secondary dust such as hearth furnace dust or zinc-containing dust such as calcination of zinc concentrate as a raw material.
  • electric furnace dust is generated as industrial waste that corresponds to about 1.5% to 2.0% of the steelmaking amount and contains zinc oxide components during scrap melting and smelting. Electric furnace dust is said to generate 8 million tons in the world and 400,000 tons in Japan.
  • Patent Document 1 relates to a method for producing zinc ingots, and relates to a process of producing a zinc-containing aqueous solution containing a zinc component using electric furnace dust or the like as a raw material, and converting the zinc component in the zinc-containing aqueous solution into a carbonate, a zinc-containing compound in at least one form of a hydroxide and an oxide, and chlorinating the zinc component of the zinc-containing compound to produce a purified zinc chloride containing purified zinc chloride; a step of dehydrating to produce anhydrous fused and purified zinc chloride containing dehydrated fused and purified zinc chloride; and electrolyzing the anhydrous fused and purified zinc chloride to produce zinc bare metal as an electrolytic product.
  • a configuration comprising:
  • the electric furnace dust 1 as a raw material containing a zinc-containing compound such as zinc oxide and an iron compound such as iron oxide and an aqueous solution of the alkaline agent 7 are brought into direct contact with each other to produce an aqueous alkaline agent solution 30 containing a zinc component as a zinc extract in which the zinc component is selectively extracted from the zinc-containing compound, and the aqueous solution of the alkaline agent 7.
  • the solid content that is not dissolved in the aqueous solution is the residue 20
  • ZnFe2O4 zinc ferrite
  • the present invention has been made through the above studies, and aims to provide a zinc recovery method capable of recovering zinc contained in electric furnace dust or the like while reliably decomposing zinc ferrite contained in the electric furnace dust or the like. aim.
  • the present inventors solved the problem that it is difficult to dissolve zinc ferrite contained in electric furnace dust or the like in an aqueous sodium hydroxide solution in the alkaline aqueous solution dissolution treatment of electric furnace dust or the like.
  • electric furnace dust containing zinc ferrite was heated to about 320°C in a container, immersed in molten sodium hydroxide, and held for about 1 hour.
  • a method for recovering zinc according to a first aspect of the present invention comprises a raw material containing a zinc component and zinc ferrite, or a treated raw material obtained by treating the raw material, and hydroxide in a molten state at a first temperature that is equal to or higher than the melting point of sodium hydroxide.
  • an alkali melting step of bringing into contact with molten sodium hydroxide, which is sodium, to decompose the zinc ferrite contained in the raw material or the treated raw material into a zinc oxide component and an iron oxide component in the molten sodium hydroxide;
  • molten sodium hydroxide which is sodium
  • a water dissolving step of obtaining a first zinc-containing aqueous solution containing a zinc component by dissolving the zinc oxide component in the aqueous solution of sodium hydroxide, and obtaining a poorly soluble substance containing an iron oxide component that is not dissolved in the aqueous sodium hydroxide solution; and a zinc recovery step of recovering the zinc component derived from the zinc-containing aqueous solution of 1.
  • the present invention further provides that in the alkali melting step, the sodium hydroxide is added with hydrogen peroxide and sodium nitrate as an oxidizing agent, or sodium sulfite, sodium thiosulfate, and dithionite as a reducing agent.
  • a second aspect is adding at least one of sodium and zinc metal.
  • the present invention provides that the raw material is washed with an aqueous sodium hydroxide solution having a pH value within the range of 8.5 or more and 10.5 or less prior to the alkali melting step.
  • the third aspect is to further include a halogen cleaning step for cleaning the halogen component contained in the raw material.
  • the present invention applies a magnetic force to the raw material or the treated raw material through a magnet prior to the alkali melting step, and a magnetic beneficiation step separating a first concentrate consisting of components attached to said magnets from a second concentrate not attached to said magnets, depending on the magnetic strength of the components in said processed feedstock; and said second mineral concentrate is sent to selectively extract the zinc component contained in said second mineral concentrate by dissolving it in an aqueous sodium hydroxide solution to produce a second zinc-containing material containing said zinc component.
  • an alkaline aqueous solution dissolving step for obtaining an aqueous solution, wherein the first mineral concentrate is sent to the alkaline melting step as the treated raw material, and the zinc ferrite in the first mineral concentrate is dissolved in the oxidized
  • a fourth aspect is decomposing into the zinc component and the iron oxide component.
  • the present invention further comprises a cleaning step of cleaning the first zinc-containing aqueous solution, wherein the cleaning step comprises cleaning the first zinc-containing aqueous solution.
  • a deironization step of contacting potassium permanganate or hydrogen peroxide as an oxidizing agent to remove solidified iron, and contacting slaked lime or quicklime with the first zinc-containing aqueous solution from which the iron has been removed.
  • a desiliconization/decarbonation/defluorination step for removing the solidified silicate, carbonate, and fluorine respectively; and a substitution step of contacting the zinc-containing aqueous solution with metal zinc to reduce and deposit metal impurity components nobler than zinc to remove the metal impurity components.
  • a sixth aspect is to include an electrolysis step for obtaining electrolytically produced zinc.
  • a seventh aspect is to include a step of separating zinc carbonate.
  • the present invention further comprises a cleaning step of cleaning the second zinc-containing aqueous solution, wherein the cleaning step is performed as an oxidizing agent for the second zinc-containing aqueous solution.
  • a ninth aspect is to include an electrolysis step for obtaining electrolytically produced zinc.
  • the zinc recovery step includes converting the zinc component in the second zinc-containing aqueous solution or in the purified second zinc-containing aqueous solution into zinc carbonate.
  • a tenth aspect is to include a step of separating zinc carbonate.
  • the present invention provides, prior to the alkali melting step, contacting the raw material or the treated raw material with an aqueous sodium hydroxide solution, and The contained zinc component is dissolved in the sodium hydroxide aqueous solution and selectively extracted to obtain a third zinc-containing aqueous solution containing the zinc component, and containing zinc ferrite that is not dissolved in the sodium hydroxide aqueous solution.
  • an eleventh aspect is to obtain a fourth zinc-containing aqueous solution containing a zinc component by dissolving the zinc oxide component in the aqueous sodium hydroxide solution in the water dissolving step.
  • the fourth zinc-containing aqueous solution is sent to the alkaline aqueous solution dissolving step, and the zinc component contained in the fourth zinc-containing aqueous solution is selected.
  • a twelfth aspect is that the zinc-containing aqueous solution is effectively extracted and becomes part of the third zinc-containing aqueous solution.
  • the raw material is treated with an aqueous sodium hydroxide solution having a pH value within the range of 8.5 or more and 10.5 or less prior to the step of dissolving the alkaline aqueous solution.
  • a thirteenth aspect is to further include a halogen cleaning step of cleaning the halogen component contained in the raw material to obtain the treated raw material.
  • the present invention further comprises a cleaning step of cleaning the third zinc-containing aqueous solution, wherein the cleaning step comprises cleaning the third zinc-containing aqueous solution.
  • a deironization step of contacting potassium permanganate or hydrogen peroxide as an oxidizing agent to remove solidified iron, and contacting slaked lime or quicklime with the third zinc-containing aqueous solution from which the iron has been removed.
  • a fourteenth aspect of the present invention is to include a substitution step of bringing metal zinc into contact with the zinc-containing aqueous solution of (1) to reduce and deposit metal impurity components nobler than zinc to remove the metal impurity components.
  • the zinc recovery step includes electrolysis using the third zinc-containing aqueous solution or a purified zinc-containing aqueous solution as an electrolyte.
  • a fifteenth aspect is to include an electrolysis step for obtaining electrolytically produced zinc.
  • a sixteenth aspect includes a step of separating zinc carbonate.
  • the present invention provides that sodium hydroxide and zinc are allowed to remain in the electrolytic tail solution of the electrolysis step, and the sodium hydroxide and zinc are allowed to remain.
  • the electrolytic tailing liquid is brought into a molten state after evaporating water and brought into contact with the raw material or the treated raw material in the alkali melting step.
  • a raw material or treated raw material containing a zinc component and zinc ferrite and sodium hydroxide in a molten state at a first temperature that is equal to or higher than the melting point of sodium hydroxide.
  • sodium hydroxide is combined with hydrogen peroxide and sodium nitrate as oxidizing agents, or sodium sulfite, sodium thiosulfate and dithionite as reducing agents. Since at least one of sodium and zinc metal is added, zinc ferrite contained in electric furnace dust or the like can be more reliably decomposed.
  • the raw material prior to the alkali melting step, is washed with an aqueous sodium hydroxide solution having a pH value within the range of 8.5 or more and 10.5 or less, Since it further includes a halogen cleaning step for cleaning the halogen components contained in the raw material to obtain the treated raw material, the halogen components contained in the electric furnace dust or the like can be reliably eluted and washed.
  • a magnetic force is applied to the raw material or the treated raw material through a magnet, and the magnetic properties of the components in the raw material or the treated raw material are detected.
  • a magnetic concentrate that separates a first concentrate consisting of components attached to the magnets and a second concentrate that is not attached to the magnets according to the strength of the magnetic concentrate, and the second concentrate is sent to an alkaline aqueous solution dissolving step of dissolving and selectively extracting the zinc component contained in the second mineral concentrate in an aqueous sodium hydroxide solution to obtain a second zinc-containing aqueous solution containing the zinc component;
  • the first mineral concentrate is sent to the alkali melting process as a processed raw material, and the zinc ferrite in the first mineral concentrate is decomposed into zinc oxide components and iron oxide components, so energy consumption is reduced. In this manner, zinc contained in the electric furnace dust or the like can be efficiently recovered while the zinc ferrite contained in the electric furnace dust or the like is more reliably decomposed.
  • the cleaning step of cleaning the first zinc-containing aqueous solution is further provided, and the cleaning step is performed as an oxidizing agent for the first zinc-containing aqueous solution.
  • the zinc recovery step performs electrolysis using the first zinc-containing aqueous solution or a purified first zinc-containing aqueous solution as the electrolyte, Since the method includes an electrolysis step for obtaining produced zinc, it is possible to stably recover electrolytically produced zinc with reduced impurity contamination at a high yield.
  • the zinc recovery step separates the zinc component in the first zinc-containing aqueous solution or in the purified first zinc-containing aqueous solution as zinc carbonate. Since the process includes a step of separating zinc carbonate, it is possible to stably recover zinc carbonate in which contamination with impurities has been reduced with a high yield.
  • the cleaning step of cleaning the second zinc-containing aqueous solution is further provided, and the cleaning step is performed as an oxidizing agent for the second zinc-containing aqueous solution.
  • the zinc recovery step performs electrolysis using the second zinc-containing aqueous solution or a purified second zinc-containing aqueous solution as the electrolyte, Since the method includes an electrolysis step for obtaining produced zinc, it is possible to stably recover electrolytically produced zinc with reduced impurity contamination at a high yield.
  • the zinc recovery step separates the zinc component in the second zinc-containing aqueous solution or in the purified second zinc-containing aqueous solution as zinc carbonate. Since the process includes a step of separating zinc carbonate, it is possible to stably recover zinc carbonate in which contamination with impurities has been reduced with a high yield.
  • the raw material or treated raw material prior to the alkali melting step, is brought into contact with an aqueous sodium hydroxide solution to remove the zinc component contained in the raw material or treated raw material. is dissolved in an aqueous sodium hydroxide solution and selectively extracted to obtain a third zinc-containing aqueous solution containing a zinc component, and an alkaline aqueous solution dissolving step for obtaining a poorly soluble substance containing zinc ferrite that is not dissolved in the aqueous sodium hydroxide solution.
  • the difficultly soluble matter containing zinc ferrite is sent as a treated raw material to the alkali melting step, decomposed into zinc oxide components and iron oxide components, and in the water dissolving step, the zinc oxide component is added to the aqueous sodium hydroxide solution. is obtained by dissolving the fourth zinc-containing aqueous solution containing the zinc component, so that the zinc ferrite contained in the electric furnace dust etc. is more reliably decomposed in a manner with reduced energy consumption, and the electric furnace dust etc. The contained zinc can be efficiently recovered.
  • the fourth zinc-containing aqueous solution is sent to the alkaline aqueous solution dissolving step, and the zinc component contained in the fourth zinc-containing aqueous solution is selectively , and becomes a part of the third zinc-containing aqueous solution, zinc contained in electric furnace dust or the like can be recovered more efficiently.
  • the raw material prior to the alkaline aqueous solution dissolving step, is washed with an aqueous sodium hydroxide solution having a pH value within the range of 8.5 or more and 10.5 or less. Since it further includes a halogen cleaning step for cleaning the halogen components contained in the raw material to obtain the treated raw material, the halogen components contained in the electric furnace dust etc. can be reliably eluted and washed.
  • the method for recovering zinc in the fourteenth aspect of the present invention further comprises a cleaning step of cleaning the third zinc-containing aqueous solution, wherein the cleaning step uses an oxidizing agent as an oxidizing agent for the third zinc-containing aqueous solution.
  • the zinc recovery step performs electrolysis using the third zinc-containing aqueous solution or a purified third zinc-containing aqueous solution as the electrolyte, Since the method includes an electrolysis step for obtaining produced zinc, it is possible to stably recover electrolytically produced zinc with reduced impurity contamination at a high yield.
  • the zinc recovery step separates the zinc component in the third zinc-containing aqueous solution or in the purified third zinc-containing aqueous solution as zinc carbonate. Since the process includes a step of separating zinc carbonate, it is possible to stably recover zinc carbonate in which contamination with impurities has been reduced with a high yield.
  • sodium hydroxide and zinc are left in the electrolytic tail solution in the electrolysis step, and the water content of the electrolytic tail solution in which sodium hydroxide and zinc are left is removed. Since it is brought into contact with raw materials or treated raw materials in the alkali melting step in a molten state after evaporation, electrolytically generated zinc with reduced contamination of impurities is obtained in a manner that reduces the consumption of sodium hydroxide and has a good yield. It can be collected stably.
  • FIG. 1 is a process diagram of a zinc recovery method according to a first embodiment of the present invention.
  • FIG. 2 is a process diagram of a method for recovering zinc according to the second embodiment of the present invention.
  • FIG. 3 is a process diagram of a zinc recovery method according to a third embodiment of the present invention.
  • FIG. 4 is a process diagram of a zinc recovery method according to a fourth embodiment of the present invention.
  • FIG. 1 is a diagram showing the steps of the method for recovering zinc in this embodiment.
  • a dehalogenation cleaning step 101 As shown in FIG. 1, in the zinc recovery method of the present embodiment, a dehalogenation cleaning step 101, an alkali melting step 102, a water dissolving step 103, a cleaning step 104, and an electrolysis step 105 are sequentially performed. Corresponds to the recovery process.
  • electric furnace dust 1 will be described as a representative raw material used in such a recovery method, but such raw materials are zinc compounds such as zinc oxide, iron compounds such as iron oxide, and compounds of iron and zinc.
  • Any material containing at least zinc ferrite may be used, and in addition to electric furnace dust, primary or secondary dust such as blast furnace dust, blast furnace/converter dust, or RHF (Rotary Hearth Furnace) dust, or zinc concentrate
  • primary or secondary dust such as blast furnace dust, blast furnace/converter dust, or RHF (Rotary Hearth Furnace) dust, or zinc concentrate
  • RHF Rotary Hearth Furnace
  • electric furnace dust 1 as a raw material containing a zinc compound such as zinc oxide, an iron compound such as iron oxide, and zinc ferrite, which is a compound of iron and zinc, is washed with a cleaning liquid 2.
  • the halogen components such as chlorine and fluorine adsorbed on the electric furnace dust 1 are eluted and separated from the electric furnace dust 1 to obtain the washed electric furnace dust 3 .
  • the cleaned electric furnace dust 3 is sent to the next alkali melting process 102 .
  • the cleaning liquid 2 an aqueous solution of a strong alkaline agent that is highly effective in eluting halogen components from the electric furnace dust 1 can be suitably used. can be suitably used as the cleaning liquid 2.
  • electric furnace dust 1 crushed to a predetermined size or less in advance is immersed in an aqueous sodium hydroxide solution as the cleaning liquid 2, and the immersed electric furnace dust 1 is immersed in the aqueous sodium hydroxide solution.
  • the electric furnace dust 1 is stirred for a predetermined period of time to form a slurry, and the halogen component adhering to the slurry is eluted from the electric furnace dust 1 .
  • the pH value of the slurry-like electric furnace dust 1 is less than 8.5, the amount of halogen components eluted from the electric furnace dust 1 cannot be secured as a practical amount, and the electric furnace dust 1
  • the pH value is preferably 8.5 or higher because unnecessary elution of zinc and lead components from the solution occurs.
  • the pH value of the slurry-like electric furnace dust 1 exceeds 10.5, the zinc component is extracted from the electric furnace dust 1, and the zinc in the washed electric furnace dust 3 to be sent to the next step It would be preferable for the pH value to be below 10.5, as this would reduce the amount of ingredients.
  • the pH value of the sodium hydroxide aqueous solution as the cleaning liquid 2 within the range of 8.5 or more and 10.5 or less.
  • the electric furnace dust 1 is washed with the cleaning liquid 2, and the used cleaning liquid 4 containing the eluted halogen component adsorbed to the electric furnace dust 1 may be simply discharged as a waste liquid, or may be discharged as a further chlorine component. may be repeatedly used as the cleaning liquid 2 for cleaning the electric furnace dust 1 again within the range where the elution of is possible.
  • the reason why the dehalogenation cleaning step 101 is provided before the alkali melting step 102 and the water dissolving step 103 is that the zinc ferrite in the electric furnace dust 1 can be decomposed and the zinc component can be extracted more appropriately. It's for.
  • the dehalogenation cleaning step 101 may be omitted.
  • the washed electric furnace dust 3 and the molten sodium hydroxide in which the sodium hydroxide 5, which is a strong alkaline agent, is in a molten state are melted under a temperature environment equal to or higher than the melting point of the sodium hydroxide 5.
  • zinc-containing solidified material 6 in which zinc ferrite is decomposed is obtained.
  • sodium hydroxide 5 is particularly used among the strong alkaline agents is that the property that zinc ferrite can be rapidly decomposed by making sodium hydroxide 5 into a molten state is taken into consideration.
  • the zinc-containing solidified material 6 from which zinc ferrite has been decomposed is sent to the next water dissolution step 103 .
  • the washed electric furnace dust 3 is immersed in an aqueous sodium hydroxide solution, which is an aqueous solution of sodium hydroxide 5, and the sodium hydroxide aqueous solution in which the washed electric furnace dust 3 is immersed is heated to remove the water content. is evaporated, and a mixture of the washed electric furnace dust 3 and sodium hydroxide 5 is heated until the melting point of the sodium hydroxide 5 is exceeded, and the sodium hydroxide 5 is melted to form molten sodium hydroxide. Molten sodium hydroxide and washed electric furnace dust 3 are brought into contact for about a predetermined time to decompose zinc ferrite contained in the electric furnace dust 3 into zinc oxide components and iron oxide components. A chemical formula in such a case is shown in (Formula 1) below.
  • the water content is is preferably brought into contact with the cleaned electric furnace dust 3 .
  • the alkali melting step 102 a mixture of the washed electric furnace dust 3 and sodium hydroxide 5 is heated until the melting point of the sodium hydroxide 5 is exceeded, and the washed electric furnace dust 3 and molten sodium hydroxide are brought into contact with each other.
  • the lower limit is a value equal to or higher than the melting point (about 318 ° C.) of sodium hydroxide 5 from the viewpoint of reliably maintaining the sodium hydroxide 5 in a molten state. is necessary, and considering practical variations, a value of 320° C. or higher is preferable.
  • the upper limit of the temperature range in this case is, of course, required to be a value lower than the boiling point of sodium hydroxide 5, but since the boiling point is a high temperature exceeding 1300° C., it is necessary to decompose the zinc ferrite.
  • a value of 600° C. or less is preferable in consideration of the amount of applied energy and the decomposition efficiency.
  • potassium hydroxide or sodium carbonate can be used as an alkaline agent that can be applied to generate a molten salt for decomposing zinc ferrite.
  • oxidizing agents added to the molten salt to promote the decomposition of zinc ferrite include hydrogen peroxide and sodium nitrate, and similarly reducing agents added to the molten salt include sodium sulfite and sodium thiosulfate. , sodium dithionite and zinc metal.
  • reducing agents added to the molten salt include sodium sulfite and sodium thiosulfate. , sodium dithionite and zinc metal.
  • alkaline agent, oxidizing agent and reducing agent are used properly depending on the state of impurities.
  • sodium hydroxide 5 preferably has a weight that is at least twice the weight of zinc and iron in the zinc ferrite.
  • the alkali melting step 102 is in a high-temperature environment at least at the melting point of sodium hydroxide 5 or higher, when the sodium hydroxide 5 once turned into an aqueous solution or the electrolytic tailing liquid 14 is introduced into this step, it is included therein. Moisture evaporates into water vapor. Therefore, while the water vapor is passed through a heat exchanger to cool and liquefy and return to water, the heat obtained by the heat exchanger is used in the alkali melting step 102 and the alkaline aqueous solution dissolving step 106 described in the second embodiment. Using it for heating is preferable from the viewpoint of improving the thermal efficiency in the alkali melting step 102 and reducing the amount of energy consumption.
  • an organic substance that reacts with chlorine to generate a volatile compound is added to an aqueous solution of sodium hydroxide 5 or an electrolytic tailing liquid 14, and the cleaned electric furnace dust 3 is immersed in the solution to hydrate.
  • the water in the aqueous solution of sodium 5 and the electrolytic tailing liquid 14 evaporates, it is preferable to react the organic matter with the chlorine in the washed electric furnace dust 3 and volatilize it as a volatile organic chlorine compound.
  • the concentration of the chlorine component contained in the washed electric furnace dust 3 is reduced, the zinc ferrite is decomposed, and the zinc-containing solidified material 6 with a reduced chlorine concentration can be obtained.
  • a practical preferred example of such an organic substance is ethanol, and in such a case, ethanol is reacted with chlorine in the washed electric furnace dust 3 to generate chloroform, which is a volatile organic chlorine compound. This will be dissipated.
  • water 7 is added to the zinc-containing solidified substance 6 in which the zinc ferrite is decomposed under a temperature environment below the melting point of sodium hydroxide, typically below the boiling point of water (100° C.).
  • An aqueous sodium hydroxide solution produced thereby and a sparingly soluble matter containing an iron oxide component that is not dissolved in the aqueous sodium hydroxide solution are obtained.
  • the zinc oxide component obtained by decomposing the zinc ferrite and the zinc oxide component originally contained in the electric furnace dust 1 are dissolved in the aqueous sodium hydroxide solution, and the aqueous sodium hydroxide solution contains zinc.
  • An aqueous sodium hydroxide solution 8 is obtained.
  • the mixture of the zinc-containing sodium hydroxide aqueous solution 8 and the hardly soluble matter containing the iron oxide component is filtered to separate the zinc-containing sodium hydroxide aqueous solution 8 and the hardly soluble matter containing the iron oxide component by filtration (solid-liquid separation). do.
  • the zinc-containing sodium hydroxide aqueous solution 8 from which the sparingly soluble matter containing the iron oxide component has been separated in this manner is sent to the next cleaning step 104 after the concentration of zinc contained therein is increased, where it contains the iron oxide component.
  • the sparingly soluble matter is discharged as residue 9 .
  • next cleaning step 104 first, the zinc-containing sodium hydroxide aqueous solution 8 is brought into contact with potassium permanganate or hydrogen peroxide 10a as an oxidizing agent to solidify iron, and the zinc-containing sodium hydroxide aqueous solution 8 is solidified.
  • potassium permanganate or hydrogen peroxide 10a as an oxidizing agent to solidify iron
  • the zinc-containing sodium hydroxide aqueous solution 8 is solidified.
  • a zinc-containing sodium hydroxide aqueous solution from which the iron 12a has been removed is obtained (deironization step).
  • slaked lime or quicklime 10b is brought into contact with the zinc-containing sodium hydroxide aqueous solution from which the iron 12a is separated in this way to solidify the silicate, carbonate and fluorine 12b, and the zinc-containing from which the iron 12a is separated.
  • Silicate, carbonate and fluorine 12b are further separated from the sodium hydroxide aqueous solution and discharged as a residue to provide a zinc-containing sodium hydroxide aqueous solution in which silicate, carbonate and fluorine 12b are separated in addition to iron 12a. obtained (steps of desiliconization, decarbonation and defluoridation).
  • metal zinc 10c is brought into contact with the aqueous zinc-containing sodium hydroxide solution from which iron 12a, silicates, carbonates and fluorine 12b have been removed in this way, and zinc in zinc-containing sodium hydroxide aqueous solution 8
  • the more noble metal impurity component 12c is reduced and deposited to obtain the zinc-containing sodium hydroxide aqueous solution 11 and the precipitated metal impurity component 12c, which are obtained by further cleaning the zinc-containing sodium hydroxide aqueous solution 8.
  • Such a final step in the cleaning step 104 is a replacement step (cementation step) in which metallic zinc 10c is applied.
  • the zinc-containing sodium hydroxide aqueous solution 11 cleaned in this way is sent to the next electrolysis step 105, and the metal impurity component 12c is discharged as a residue.
  • the metallic zinc 10c is typically introduced into the zinc-containing sodium hydroxide aqueous solution 8 as metallic zinc powder, and the zinc-containing sodium hydroxide aqueous solution 8 into which the metallic zinc powder has been introduced is heated. Stirring at a high speed while maintaining the predetermined temperature accelerates the cementation reaction, and as a result, metal impurity components nobler than zinc in the zinc-containing sodium hydroxide aqueous solution 8 can be precipitated quickly.
  • the metallic zinc 10c may be applied as a metallic zinc plate rather than a metallic zinc powder, in which case the zinc-containing aqueous sodium hydroxide solution 8 is directed toward the stationary fixed metallic zinc plate.
  • the cementation reaction is also accelerated by being flowed and brought into contact with the metal zinc plate.
  • metallic zinc powder when metallic zinc powder is used, the entire surface of the metallic zinc powder is covered with precipitated metallic impurity components during the cementation reaction, and the central portion of the metallic zinc powder can contribute to the cementation reaction.
  • the degree of freedom in setting the contact area between it and the zinc-containing sodium hydroxide aqueous solution 8 is high, so the contact area can be increased, and the cementation reaction In addition to being able to reliably accelerate the process, it is also possible to quickly replace the metal zinc plate on which metal impurity components have precipitated.
  • the metal zinc plate may be rotated with respect to the flow of the zinc-containing aqueous sodium hydroxide solution 8 .
  • the cleaning step 104 when the iron removal step, the silicon removal, decarbonation, defluoridation step, and the replacement step are employed, the iron removal step, the silicon removal, decarbonation, defluoridation step, and the replacement step are performed in this order.
  • the deironization step is an oxidation step for removing precipitates, which are oxides such as iron and manganese obtained by an oxidizing agent, while the replacement step is a reduction step.
  • the oxidative deironization step it is highly necessary to perform the oxidative deironization step before the reduction substitution step.
  • the cost of removing iron in the reduction substitution process is relatively high compared to the cost of removing iron in the oxidative deironization process. It is preferable to perform the iron removal step before the replacement step.
  • the desiliconization, decarbonation, and defluoridation process which removes silicates, carbonates, and fluorine by adding slaked lime or ortholime, is theoretically superior to the oxidative deironization process and the reduction substitution process.
  • the order of execution does not matter, according to the knowledge obtained from the experimental results obtained so far, the desiliconization, decarbonation, and defluoridation steps are performed after the oxidative deironization step and before the reduction substitution step. It was found that the removal rate of such impurities was most improved when the deferrous step, the desiliconizing/decarbonating/defluorinating step, and the substitution step were performed in that order, when the cleaning step was performed before.
  • the iron removal process, the silicon removal/decarbonate/fluorination process, and the replacement process are executed in this order.
  • the cleaning step 104 may be omitted when the zinc-containing aqueous sodium hydroxide solution 8 contains few impurity components such as iron, silicon, carbonate, fluorine, and metals nobler than zinc.
  • a demanganization step for removing manganese by adding an oxidizing agent or the like and a dechlorination step for dechlorinating by adding copper (I) oxide or silver nitrate may be employed. It is also possible to combine these steps as needed. However, if it is considered that the halogen component is reduced in advance in the dehalogenation cleaning step 101 or that the chlorine component can be reduced in the alkali melting step 102, the demanganization step is preferred over the dechlorination step. It can be said that the degree is higher.
  • electrolysis is performed using the cleaned zinc-containing sodium hydroxide aqueous solution 11 as an electrolyte, and electrolytically produced zinc 13, which is an electrolysis product, is deposited on the cathode side, and solid-liquid separation is performed. Recovered as a solid.
  • the electrolytic solution 14, which is the electrolytic solution after the electrolytically generated zinc 13 has been recovered may be discharged as it is as a waste liquid, but since it contains sodium hydroxide, the electrolytic solution 14 is returned to the alkali melting step 102 as it is.
  • the electrolytic tailing liquid 14 can be produced without using new sodium hydroxide 5 in the alkali melting step 102 from the middle of the current zinc recovery method or from the start of the next zinc recovery method.
  • a chisel may be used to bring it into contact with the cleaned electric furnace dust 3 .
  • the zinc component may be left in the electrolytic tailing liquid 14 and the zinc-containing electrolytic tailing liquid 14 may be returned to the alkali melting step 102 as it is.
  • the electrolyzed tail liquid 14 is used as an electrolytic solution in the electrolysis step 105 while increasing the zinc concentration through at least the alkali melting step 102 and the water dissolving step 103.
  • the electrolyzed tail liquid 14 preferably contains sodium hydroxide at a concentration of 200 g/L or higher and zinc at a concentration of 10 g/L or higher.
  • Example 1 In the alkali melting step 102, the electric furnace dust 3 (weight: 150 g) after completion of the dehalogenation cleaning in the dehalogenation cleaning step 101 and the electrolytic tailing liquid 14 (volume: When 1 L) was charged into an iron crucible and heated, the liquid temperature was about 300 ° C., and the evaporation of water stopped. did. After 1 hour has passed, the heating is stopped, and in the water dissolving step 103, when the temperature of the solidified product produced by cooling the melt 6 becomes less than 100°C, water injection is started, and the volume is reduced to 1 L with water. Dilution was performed by diluting.
  • this leachate was subjected to cementation by contacting the zinc metal (powder or plate) 10c at a liquid temperature of 60° C. for 24 hours to remove impurities such as Cu, Pb, Cd and Ni 12c.
  • electrowinning was performed in the electrolysis step 105 .
  • the electrowinning conditions were set such that the current density was 600 A per square meter, the electrolyte concentration was 400 g/L for NaOH and 50 g/L for Zn, and the temperature of the electrolyte was 40°C. Electrolytically generated zinc 13 with a purity of 99.995% was obtained.
  • a liquid supply tank was used to circulate and supply the electrolytic solution so that the concentration of Zn in the electrolytic solution was 55 g/L and the concentration of Zn in the electrolytic solution was 50 g/L.
  • a part of the electrolytic tailing liquid 14 is extracted and used as the leachate 8 in the subsequent water dissolving step 103 via the alkaline aqueous solution before evaporation in the alkali melting step 102.
  • the concentration of Zn was increased from 50 g/L to 110 g/L.
  • the analysis values of leachate 11 (cleaned zinc-containing sodium hydroxide aqueous solution) after cleaning by cementation are shown in Table 1 below. .
  • FIG. 2 is a diagram showing the steps of the zinc recovery method in this embodiment.
  • the zinc recovery method according to the present embodiment has an alkaline aqueous solution dissolution step 106 immediately following the dehalogenation cleaning step 101 as compared with the zinc recovery method according to the first embodiment.
  • the main difference is that In the present embodiment, the description will focus on such differences, and the same constituent elements will be given the same reference numerals, and the description thereof will be omitted or simplified.
  • an alkaline aqueous solution dissolving step 106 is provided immediately after the dehalogenation cleaning step 101 .
  • the reason why the dehalogenation cleaning step 101 is provided before the alkali aqueous solution dissolving step 106 is that the zinc component in the electric furnace dust 1 can be extracted more appropriately.
  • the washed electric furnace dust 3 is brought into contact with an aqueous sodium hydroxide solution, which is an aqueous solution of sodium hydroxide 5, so that zinc contained in the washed electric furnace dust 3 is dissolved.
  • the components are dissolved in an aqueous sodium hydroxide solution and selectively extracted to obtain an aqueous zinc-containing sodium hydroxide solution 15 containing a zinc component, and a sparingly soluble matter 16 containing zinc ferrite that is not dissolved in the aqueous sodium hydroxide solution. It is.
  • the reason why sodium hydroxide is used as the strong alkaline agent is that the zinc component can be efficiently extracted and that it can be shared with the one used in the alkali melting step 102 .
  • the electric furnace dust 3 is brought into contact with an aqueous sodium hydroxide solution, and the zinc component contained in the washed electric furnace dust 3 is dissolved in the aqueous sodium hydroxide solution to selectively extract the zinc-containing sodium hydroxide containing the zinc component.
  • the chemical formula for obtaining the aqueous solution 15 is shown in (Formula 2) below.
  • the zinc-containing sodium hydroxide aqueous solution 15 thus obtained is sent to the next cleaning step 104, while the poorly soluble matter 16 containing zinc ferrite obtained on the other hand is sent to the alkali melting step 102,
  • the zinc ferrite decomposes into a zinc oxide component and an iron oxide component.
  • the zinc-containing solidified material 6 in which the zinc ferrite is decomposed is sent to the next water dissolution step 103 to become the zinc-containing sodium hydroxide aqueous solution 8, which is sent to the alkaline aqueous solution dissolution step 106, and is sent to the zinc-containing
  • the zinc component contained in the sodium hydroxide aqueous solution 8 is selectively extracted and becomes a part of the zinc-containing sodium hydroxide aqueous solution 15 .
  • the zinc-containing aqueous sodium hydroxide aqueous solution 8 is generated and sent to the alkaline aqueous solution dissolving step 106, it is used together with the sodium hydroxide 5 to Alternatively, without using sodium hydroxide 5, the zinc-containing aqueous sodium hydroxide solution 8 may be used to bring it into contact with the cleaned electric furnace dust 3.
  • an alkaline aqueous solution dissolving step 106 is provided, and the poorly soluble matter 16 containing zinc ferrite is sent from the alkaline aqueous solution dissolving step 106 toward the alkali melting step 102, and the zinc from which the zinc ferrite is decomposed is
  • the so-called countercurrent two-stage treatment process is adopted in which the contained solidified material 6 is sent to the alkali aqueous solution dissolution process 106 as a zinc-containing sodium hydroxide aqueous solution 8 via the following water dissolution process 103. For some reason.
  • the alkali melting step 102 is a treatment that requires a higher temperature environment than the alkaline aqueous solution dissolving step 106, and thus consumes a large amount of energy. This is because, by performing the treatment not only in the alkali melting step 102 but also in the alkaline aqueous solution dissolving step 106, the processing time in the alkali melting step 102 can be shortened, and the energy consumption can be reduced. . For example, in a certain electric furnace dust 1, if 88% of the zinc component is contained in zinc oxide and the remaining 12% is contained in zinc ferrite, an alkaline aqueous solution dissolution that can be performed in a temperature environment of 100 ° C.
  • the electrolytic tailing liquid 14 is returned to the alkaline aqueous solution dissolving step 106, and the washed electric furnace dust 3 is brought into contact with the electrolytic tailing liquid 14 alone or together with the aqueous sodium hydroxide solution. It may be used as an alkaline aqueous solution for
  • Example 2 In the alkali melting step 102, the dust 16 (among the contained zinc components, the zinc oxide is dissolved by the alkaline aqueous solution leaching, and the zinc component in the zinc ferrite remains. : Weight 70 g) and electrolytic tailing liquid 14 (NaOH concentration 450 g / L, Zn concentration 50 g / L: volume 1 L) were placed in a 2 L iron container and heated and stirred, and the liquid temperature was about 300. After that, the temperature was further increased to 400°C and this was maintained for 1 hour.
  • electrolytic tailing liquid 14 NaOH concentration 450 g / L, Zn concentration 50 g / L: volume 1 L
  • the heating was stopped, and in the water dissolution step 103, the melt 6 was cooled down to less than 100° C., water was started to be poured, and diluted to the original volume of 1 L. Stirring was carried out while heating until the liquid temperature reached 100° C., and the slurry was filtered after confirming that the zinc component was dissolved by maintaining this state for several hours. After filtration, the cake of the solid (iron residue 9) was washed and analyzed, confirming that 98% or more of the Zn in the electric furnace dust 1 was dissolved.
  • the electric furnace dust 3 (weight: 175 g) after completion of dehalogenation cleaning in the dehalogenation cleaning step 101 and the filtrate 8 (volume: 1 L) after completion of the alkali melting step 102 and water dissolution step 103 are used. was placed in an iron reaction vessel and heated with stirring to raise the liquid temperature to 120° C., and this liquid temperature was maintained for 2 hours. At this time, while the liquid temperature reached 120°C, the water content evaporated and the dissolved components were concentrated. After 2 hours had passed, the solution was filtered and solid-liquid separated. At that time, about 70 g of solid (iron residue) 16 was collected by dry weight.
  • This dust is used as the primary leaching completed dust, which is used as a raw material for the subsequent alkali melting step 102 .
  • concentration of Zn in the liquid obtained by solid-liquid separation was increased to approximately NaOH (concentration of 450 g/L) and Zn (concentration of 120 g/L) as the leachate 15 .
  • an oxidizing agent (KMnO4, H2O2) 10a was added using this leachate 15 as an oxidizing cleaning liquid, and after stirring for 1 hour, precipitates were separated by filtration.
  • CaO 10b was added to this leachate as a Ca purification liquid, and after stirring for 1 hour, the precipitate was separated by filtration.
  • this leachate was subjected to cementation for contacting zinc metal (powder or plate) 10c at a liquid temperature of 60° C. for 24 hours to remove impurities such as Cu, Pb, Cd and Ni 12c.
  • Electrowinning was performed in electrolysis step 105 using the leachate 11 for which a series of liquid purification up to this cementation was completed as an electrolytic solution. Electrowinning conditions were set such that the current density was 600 A per square meter, the electrolyte concentration was 450 g/L for NaOH and 55 g/L for Zn, and the temperature of the electrolyte was 40°C. As a result, electrolytically generated zinc 13 with a purity of 99.995% was obtained.
  • the concentration of the electrolytic solution As for the concentration of the electrolytic solution, a feed tank was used in which the Zn concentration in the electrolyte feed solution was 55 g/L and the Zn concentration in the electrolytic tail solution was 50 g/L. A part of the electrolytic tailing liquid 14 is extracted and passed through the alkaline aqueous solution before evaporation in the alkaline melting step 102, and used as the leaching solutions 8 and 15 in the subsequent water dissolving step 103 and alkaline aqueous solution dissolving step 106. The Zn concentration of 50 g/L was increased to 120 g/L by dissolving in an alkaline aqueous solution.
  • FIG. 3 is a diagram showing the steps of the zinc recovery method in this embodiment.
  • step 107 is the main difference.
  • the description will focus on such differences, and the same constituent elements will be given the same reference numerals, and the description thereof will be omitted or simplified.
  • the magnetic separation step 107 can be performed before the dehalogenation cleaning step 101 if the electric furnace dust 3 before cleaning can be subjected to magnetic separation. Further, the magnetic beneficiation process 107 may be applied to the zinc recovery method according to the first embodiment.
  • a magnetic beneficiation process 107 is provided immediately after the dehalogenation cleaning process 101, and prior to the alkaline aqueous solution dissolving process 106, the magnetic beneficiation process 107 is typically applied to the cleaned electric furnace dust 3 by an electromagnet.
  • a magnetic force is applied through a certain magnet, and the washed electric furnace dust 3 is separated from the adherent concentrate 18 consisting of components (mainly zinc ferrite and iron components) attached to the magnet according to the magnetic strength of the components inside.
  • a residual mineral concentrate 19 other than the attached mineral concentrate 18 in the washed electric furnace dust 3 and not attached to the magnet in the magnetic separation process 107, a commercially available wet high magnetic force magnetic separator can be used.
  • Deposited mineral concentrate 18 is sent to an alkaline melting process 102 where it is contacted with molten sodium hydroxide to decompose zinc ferrite in the deposited mineral concentrate 18 into zinc oxide and iron oxide components, thus decomposing zinc ferrite.
  • the decomposed zinc-containing solidified material 6 is sent to the next water dissolution step 103 .
  • water 7 is brought into contact with zinc-containing solidified matter 6 in which zinc ferrite has been decomposed to obtain zinc-containing sodium hydroxide aqueous solution 8 and residue 9 composed of hardly soluble substances containing iron oxide components.
  • the residue 9 contains a large amount of zinc component
  • part or all of the residue 9′ is sent to the alkaline aqueous solution dissolution step 106, and the zinc component is may be selectively extracted.
  • the residual mineral concentrate 19 is sent to an alkaline aqueous solution dissolution step 106, where the zinc component contained in the residual mineral concentrate 19 is dissolved in an aqueous sodium hydroxide solution and selectively extracted to obtain zinc-containing water containing zinc components.
  • An aqueous sodium oxide solution 15 is obtained, and a sparingly soluble substance 16 that is not dissolved in the aqueous sodium hydroxide solution is obtained.
  • the zinc-containing sodium hydroxide aqueous solution 15 thus obtained is sent to the next cleaning step 104, while the sparingly soluble matter 16 obtained on the other hand is discharged as a residue.
  • Zinc ferrite may be decomposed into a zinc oxide component and an iron oxide component.
  • the magnetically attached dust 18 (referring to the component adhering to the magnet in the total weight of 175 g of the electric furnace dust, the weight of which is 67 g) and the alkali Electrolytic tailing liquid 14 (NaOH concentration 450 g/L and Zn concentration 50 g/L: volume 1 L) was charged into a 2 L iron container and heated and stirred. , which was further heated to raise the temperature to 400°C and held for 1 hour. After 1 hour, the heating was stopped, and in the water dissolution step 103, the melt 6 was cooled down to less than 100° C., water was started to be poured, and diluted to the original volume of 1 L.
  • the iron leaching residue 9 can also be put into the alkaline aqueous solution dissolving step 106 when dissolution of zinc is insufficient.
  • the non-magnetic dust 19 (the component that did not adhere to the magnet in the total weight of 175 g of the electric furnace dust) is removed through the magnetic separation step 107. (108 g in weight) and the filtrate 8 (volume 1 L) after the completion of the alkali melting step 102 and the water dissolving step 103 are charged into an iron reaction vessel and heated while stirring to raise the liquid temperature to 120°C. Then, this liquid temperature was maintained for 2 hours (similar to Experimental Example 2). After 2 hours, the solution was filtered and solid-liquid separated to obtain a solid 16 (iron residue).
  • this leachate was subjected to cementation for contacting zinc metal (powder or plate) 10c at a liquid temperature of 60° C. for 24 hours to remove impurities such as Cu, Pb, Cd and Ni 12c.
  • Electrowinning was performed in electrolysis step 105 using the leachate 11 for which a series of liquid purification up to this cementation was completed as an electrolytic solution. Electrowinning conditions were set such that the current density was 600 A per square meter, the electrolyte concentration was 450 g/L for NaOH and 55 g/L for Zn, and the temperature of the electrolyte was 40°C. As a result, electrolytically generated zinc 13 with a purity of 99.995% was obtained.
  • the concentration of the electrolytic solution As for the concentration of the electrolytic solution, a feed tank was used in which the Zn concentration in the electrolyte feed solution was 55 g/L and the Zn concentration in the electrolytic tail solution was 50 g/L. A part of the electrolytic tailing liquid 14 is extracted and passed through the alkaline aqueous solution before evaporation in the alkaline melting step 102, and is used as the leaching solutions 6 and 8 in the subsequent water dissolving step 103 and alkaline aqueous solution dissolving step 106. The Zn concentration of 50 g/L was increased to 120 g/L by dissolving in an alkaline aqueous solution.
  • FIG. 4 is a diagram showing the steps of the zinc recovery method in this embodiment.
  • the zinc recovery method according to the present embodiment has a zinc carbonate separation step 108 instead of the electrolysis step 105 as the zinc recovery step, as compared with the zinc recovery method according to the third embodiment.
  • the main difference is that In the present embodiment, the description will focus on such differences, and the same constituent elements will be given the same reference numerals, and the description thereof will be omitted or simplified.
  • the zinc carbonate separation step 108 may be applied instead of the electrolysis step 105 of the zinc recovery method according to the first and second embodiments.
  • the zinc-containing sodium hydroxide aqueous solution 11 that has undergone the cleaning step 104 is brought into contact with carbon dioxide gas 20 to separate the zinc component in the zinc-containing sodium hydroxide aqueous solution 11 as zinc carbonate 21. It is.
  • carbon dioxide 20 is blown into the zinc component in the zinc-containing sodium hydroxide aqueous solution 11 to precipitate zinc carbonate. is filtered to obtain solid zinc carbonate 21.
  • the zinc carbonate 21 can be made into a product by drying after washing with water. Also, since the residual liquid 22 from the zinc carbonate separation step 108 contains sodium hydroxide, it is returned to the alkali melting step 102 .
  • Zinc oxide can also be obtained by roasting solid zinc carbonate 21 .
  • Example 4 As in Experimental Example 3, the steps up to cleaning step 104 were performed while increasing the concentration of Zn from 50 g/L to 120 g/L by dissolving in an alkaline aqueous solution. Carbon dioxide gas 20 was blown into the leachate 11 after completion of the liquid purification to deposit zinc carbonate 21, which was collected by filtration. In addition, the analysis values of the leachate 11 (cleaned zinc-containing sodium hydroxide aqueous solution) after completion of liquid cleaning by cementation were similar to the values shown in (Table 1) of Experimental Example 1, and the concentration of the analyzed component was were all below the lower limit of measurement.
  • the raw material 1 containing the zinc component and zinc ferrite or the treated raw materials 3, 16, and 18 are heated at a first temperature equal to or higher than the melting point of sodium hydroxide.
  • molten sodium hydroxide 5, 14 in a molten state to convert zinc ferrite contained in raw material 1 or treated raw materials 3, 16, 18 in molten sodium hydroxide into zinc oxide component and Alkaline melting step 102 to decompose into iron oxide components, and sodium hydroxide, zinc oxide component and iron oxide component in which the temperature of molten sodium hydroxide is lowered at a second temperature below the boiling point of water.
  • the sodium hydroxides 5 and 14 are combined with hydrogen peroxide and sodium nitrate as oxidizing agents, or sodium sulfite and sodium thiosulfate as reducing agents. , sodium dithionite, and zinc metal, zinc ferrite contained in the electric furnace dust 1 and the like can be more reliably decomposed.
  • the raw material 1 prior to the alkali melting step 102, is dissolved in an aqueous sodium hydroxide solution having a pH value within the range of 8.5 or more and 10.5 or less. is washed with the cleaning liquid 2 to wash the halogen components contained in the raw material 1 to obtain the treated raw material 3, so that the halogen components contained in the electric furnace dust 1 etc. are reliably removed. can be washed by eluting with
  • a magnetic force is applied to the raw material 1 or the treated raw material 3 via a magnet, a magnetic beneficiation step 107 that separates a first concentrate 18 consisting of the components attached to the magnet and a second concentrate 19 not attached to the magnet, depending on the magnetic strength of the components in the finished feedstock 3; , a second mineral concentrate 19 is sent to selectively extract the zinc component contained in the second mineral concentrate 19 by dissolving it in an aqueous sodium hydroxide solution to form a second zinc-containing aqueous solution containing the zinc component.
  • the first mineral concentrate 18 is sent as a treated raw material to an alkaline melting step 102 to convert the zinc ferrite in the first mineral concentrate 18 into a zinc oxide component. and iron oxide components, the zinc 13, 21 contained in the electric furnace dust 1 etc. is decomposed more reliably while reducing the amount of energy consumed. can be efficiently recovered.
  • the zinc recovery methods of the first, third, and fourth embodiments further include a cleaning step 104 for cleaning the first zinc-containing aqueous solution 8 or the second zinc-containing aqueous solution 15, wherein the cleaning step 104 , a deironization step of contacting the first zinc-containing aqueous solution 8 or the second zinc-containing aqueous solution 15 with potassium permanganate or hydrogen peroxide 10a as an oxidizing agent to remove solidified iron; A desiliconization/decarbonation/defluorination step of removing the solidified silicate, carbonate and fluorine by contacting the first zinc-containing aqueous solution with slaked lime or quicklime 10b, and iron and silicate , metal zinc 10c is brought into contact with the first zinc-containing aqueous solution 8 or the second zinc-containing aqueous solution 15 from which carbonate and fluorine have been removed, and metal impurity components nobler than zinc are reduced and precipitated to obtain metal impurity components. and a substitution step of removing the cleaning
  • the zinc recovery step includes the first zinc-containing aqueous solution 8, the second zinc-containing aqueous solution 15, or the first zinc-containing aqueous solution 8 or the second zinc-containing aqueous solution. Since it includes an electrolysis step 105 in which electrolytically generated zinc 13 is obtained by performing electrolysis using a purified zinc-containing aqueous solution 15 as an electrolytic solution 11, the electrolytically generated zinc 13 with reduced contamination of impurities is stably produced with a high yield. can be recovered.
  • the zinc recovery step is carried out in the first zinc-containing aqueous solution 8, in the second zinc-containing aqueous solution 15, in the first zinc-containing aqueous solution 8, or in the second zinc-containing aqueous solution 8. Since it includes a zinc carbonate separation step 108 for separating the zinc component in the purified zinc-containing aqueous solution 15 11 as zinc carbonate 21 in 2, the zinc carbonate 21 with reduced impurity contamination is stably produced with a good yield. can be recovered.
  • the raw material 1 or the treated raw material 3 prior to the alkali melting step 102, is brought into contact with an aqueous sodium hydroxide solution, and the raw material 1 or the treated raw material 3 contains A zinc component is dissolved in an aqueous sodium hydroxide solution and selectively extracted to obtain a third zinc-containing aqueous solution 15 containing a zinc component, and a sparingly soluble matter 16 containing zinc ferrite that is not dissolved in the aqueous sodium hydroxide solution.
  • An alkaline aqueous solution dissolving step 106 is further provided, and the poorly soluble matter 16 containing zinc ferrite is sent as a treated raw material to an alkali melting step 102, decomposed into zinc oxide components and iron oxide components, and dissolved in water in a water dissolving step 103. Since the fourth zinc-containing aqueous solution 8 containing the zinc component is obtained by dissolving the zinc oxide component in the sodium oxide aqueous solution, the zinc ferrite contained in the electric furnace dust 1 etc. The zinc 13 and 21 contained in the electric furnace dust 1 and the like can be efficiently recovered while being reliably decomposed.
  • the fourth zinc-containing aqueous solution 8 is sent to the alkaline aqueous solution dissolving step 106, and the zinc component contained in the fourth zinc-containing aqueous solution 8 is selectively and becomes a part of the third zinc-containing aqueous solution 15, the zinc 13 and 21 contained in the electric furnace dust 1 and the like can be recovered more efficiently.
  • the raw material 1 prior to the alkaline aqueous solution dissolving step 106, the raw material 1 is washed with an aqueous sodium hydroxide solution having a pH value within the range of 8.5 or more and 10.5 or less, Since it further includes a halogen cleaning step 101 for cleaning the halogen components contained in the raw material 1 to obtain the treated raw material, the halogen components contained in the electric furnace dust 1 and the like can be reliably eluted and washed. .
  • the method for recovering zinc of the second embodiment further includes a cleaning step 104 for cleaning the third zinc-containing aqueous solution 15, and the cleaning step 104 serves as an oxidant to the third zinc-containing aqueous solution 15.
  • a deironization step of contacting potassium permanganate or hydrogen peroxide 10a to remove solidified iron, and a third zinc-containing aqueous solution 15 from which iron has been removed is brought into contact with slaked lime or quicklime 10b to solidify each.
  • Metal zinc is added to the third zinc-containing aqueous solution 15 from which iron, silicates, carbonates and fluorine are removed, and a desiliconization/decarbonation/defluorination step for removing silicates, carbonates and fluorine.
  • the zinc recovery step performs electrolysis using the third zinc-containing aqueous solution 15 or the purified third zinc-containing aqueous solution 11 11 as the electrolyte. Since the electrolytic process 105 for obtaining the produced zinc 13 is included, the electrolytically produced zinc 13 with reduced contamination of impurities can be stably recovered with a high yield.
  • the zinc recovery step removes the zinc component in the third zinc-containing aqueous solution 15 or in the cleaned third zinc-containing aqueous solution 11 by zinc carbonate 21 . Since the method includes the zinc carbonate separation step 108 for separating as a zinc carbonate, the zinc carbonate 21 with reduced contamination of impurities can be stably recovered with a high yield.
  • sodium hydroxide and zinc are left in the electrolytic tail solution 14 in the electrolysis step 105, and the electrolytic tail solution 14 in which sodium hydroxide and zinc are left is After evaporating the water content, the molten state is brought into contact with the raw material 1 or the treated raw materials 3, 16, and 18 in the alkali melting step 102, so that the consumption of sodium hydroxide is reduced. It is possible to stably recover the electrolytically generated zinc 13 with a reduced .
  • the present invention is not limited to the above-described embodiments in terms of the shape, arrangement, number, etc. of the constituent elements. Needless to say, it can be changed as appropriate within a range that does not occur.
  • the present invention can provide a zinc recovery method capable of recovering zinc contained in electric furnace dust or the like while reliably decomposing zinc ferrite contained in the electric furnace dust or the like. Because of its universal nature, it is widely used in the electric furnace process, which is one of the ironmaking processes, in addition to electric furnace dust generated during scrap melting and smelting, as well as blast furnace dust, blast furnace/converter furnace dust, or RHF (Rotary Hearth Furnace). : Rotary Hearth Furnace) It is expected to be applicable to a zinc recovery method using primary dust or secondary dust such as dust and calcined ore for zinc concentrate as raw materials.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Electrolytic Production Of Metals (AREA)
  • Processing Of Solid Wastes (AREA)
  • Manufacture And Refinement Of Metals (AREA)
PCT/JP2023/004931 2022-02-15 2023-02-14 亜鉛回収方法 Ceased WO2023157826A1 (ja)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP23756351.5A EP4481072A4 (en) 2022-02-15 2023-02-14 ZINC RECOVERY PROCESS
JP2024501376A JP7756379B2 (ja) 2022-02-15 2023-02-14 亜鉛回収方法
US18/836,436 US20250154676A1 (en) 2022-02-15 2023-02-14 Zinc recovery method
CN202380020367.7A CN118660980A (zh) 2022-02-15 2023-02-14 锌回收方法

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2022-021364 2022-02-15
JP2022021364 2022-02-15

Publications (1)

Publication Number Publication Date
WO2023157826A1 true WO2023157826A1 (ja) 2023-08-24

Family

ID=87578277

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2023/004931 Ceased WO2023157826A1 (ja) 2022-02-15 2023-02-14 亜鉛回収方法

Country Status (5)

Country Link
US (1) US20250154676A1 (https=)
EP (1) EP4481072A4 (https=)
JP (1) JP7756379B2 (https=)
CN (1) CN118660980A (https=)
WO (1) WO2023157826A1 (https=)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57501384A (https=) * 1980-05-28 1982-08-05
JP2012201901A (ja) * 2011-03-23 2012-10-22 Sumitomo Metal Mining Co Ltd 酸化亜鉛焼鉱の製造方法
WO2017187973A1 (ja) * 2016-04-28 2017-11-02 国立大学法人東北大学 鉄鋼ダストの処理方法、亜鉛の生産方法、鉄鋼原料の生産方法、及び鉄鋼原料
JP2019119895A (ja) 2017-12-28 2019-07-22 株式会社キノテック 亜鉛地金の製造方法
CN110863219A (zh) * 2019-12-04 2020-03-06 北京环丁环保大数据研究院 一种含锌转炉尘泥资源化利用的方法
JP2021008385A (ja) * 2019-07-02 2021-01-28 株式会社キノテック 炭酸亜鉛の製造方法

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111057858B (zh) * 2020-03-12 2020-07-21 中国恩菲工程技术有限公司 从铜渣中提取铜、铁、锌和铅的综合回收方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57501384A (https=) * 1980-05-28 1982-08-05
JP2012201901A (ja) * 2011-03-23 2012-10-22 Sumitomo Metal Mining Co Ltd 酸化亜鉛焼鉱の製造方法
WO2017187973A1 (ja) * 2016-04-28 2017-11-02 国立大学法人東北大学 鉄鋼ダストの処理方法、亜鉛の生産方法、鉄鋼原料の生産方法、及び鉄鋼原料
JP2019119895A (ja) 2017-12-28 2019-07-22 株式会社キノテック 亜鉛地金の製造方法
JP2021008385A (ja) * 2019-07-02 2021-01-28 株式会社キノテック 炭酸亜鉛の製造方法
CN110863219A (zh) * 2019-12-04 2020-03-06 北京环丁环保大数据研究院 一种含锌转炉尘泥资源化利用的方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4481072A4

Also Published As

Publication number Publication date
EP4481072A1 (en) 2024-12-25
US20250154676A1 (en) 2025-05-15
EP4481072A4 (en) 2026-04-08
CN118660980A (zh) 2024-09-17
JP7756379B2 (ja) 2025-10-20
EP4481072A9 (en) 2025-02-26
JPWO2023157826A1 (https=) 2023-08-24

Similar Documents

Publication Publication Date Title
KR20160034927A (ko) 전기로 제강 더스트로부터의 아연 회수 방법 및 전기로 제강 더스트로부터의 아연 회수 장치
JP6648674B2 (ja) 金属マンガンの製造方法
JP6219325B2 (ja) 金属マンガンの製造方法
JP5370777B2 (ja) 銅硫化物からの銅の回収方法
JP5935098B2 (ja) 亜鉛製造方法
JP6656709B2 (ja) 亜鉛地金の製造方法
CN114934170A (zh) 一种从铜电解黑铜泥中分离砷、锑及回收铜的方法
CN114015879B (zh) 一种砷冰铜火法处理回收铜的方法
KR20230138446A (ko) 유가 금속의 회수 방법 및 회수 장치
JP6411001B1 (ja) 金属マンガンの製造方法
KR101763549B1 (ko) 출발 물질들로부터 비소를 분리하는 방법 및 장치
JP6591675B2 (ja) 金属マンガンの製造方法
JP7756379B2 (ja) 亜鉛回収方法
JP7243749B2 (ja) 有価金属の回収方法及び回収装置
Behnajady et al. Spongy Zinc Powder Production from Cold Filter Cake to Use in Cold Purification Stage
US20070041883A1 (en) Process for hydrometallurgical treatment of electric arc furnace dust
JP2020132957A (ja) 銀の回収方法
JP7193136B2 (ja) 炭酸亜鉛の製造方法
KR100236663B1 (ko) 금속 및 화학적 유용물 회수방법
JPWO2023157826A5 (https=)
JP7565585B2 (ja) 炭酸亜鉛の製造方法
WO2024154734A1 (ja) 亜鉛回収方法及びジンクフェライト分解方法
KR102678814B1 (ko) 아연, 구리 폐기물로부터 용매추출을 이용한 유가금속 회수방법
JP2017150029A (ja) 金属マンガンの製造方法
RU2098502C1 (ru) Способ переработки свинецсодержащих пылей

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 23756351

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 202380020367.7

Country of ref document: CN

ENP Entry into the national phase

Ref document number: 2024501376

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 18836436

Country of ref document: US

WWE Wipo information: entry into national phase

Ref document number: 2401005221

Country of ref document: TH

WWE Wipo information: entry into national phase

Ref document number: 202447068177

Country of ref document: IN

WWE Wipo information: entry into national phase

Ref document number: 2023756351

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2023756351

Country of ref document: EP

Effective date: 20240916

WWP Wipo information: published in national office

Ref document number: 202447068177

Country of ref document: IN

WWP Wipo information: published in national office

Ref document number: 18836436

Country of ref document: US