CN114350935A - Electric furnace ash recycling treatment method - Google Patents

Electric furnace ash recycling treatment method Download PDF

Info

Publication number
CN114350935A
CN114350935A CN202210031344.3A CN202210031344A CN114350935A CN 114350935 A CN114350935 A CN 114350935A CN 202210031344 A CN202210031344 A CN 202210031344A CN 114350935 A CN114350935 A CN 114350935A
Authority
CN
China
Prior art keywords
zinc
leaching
solution
electric furnace
primary
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202210031344.3A
Other languages
Chinese (zh)
Inventor
郭灵巧
安强
李正波
邓舒曼
黎铮
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.)
Chongqing University
Original Assignee
Chongqing University
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 Chongqing University filed Critical Chongqing University
Priority to CN202210031344.3A priority Critical patent/CN114350935A/en
Publication of CN114350935A publication Critical patent/CN114350935A/en
Pending 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
    • C22B1/00—Preliminary treatment of ores or scrap
    • C22B1/02—Roasting processes
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G49/00—Compounds of iron
    • C01G49/0018—Mixed oxides or hydroxides
    • C01G49/0063—Mixed oxides or hydroxides containing zinc
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G49/00—Compounds of iron
    • C01G49/02—Oxides; Hydroxides
    • C01G49/06—Ferric oxide (Fe2O3)
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G9/00—Compounds of zinc
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G9/00—Compounds of zinc
    • C01G9/02—Oxides; Hydroxides
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G9/00—Compounds of zinc
    • C01G9/06—Sulfates
    • 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
    • C22B19/20—Obtaining zinc otherwise than by distilling
    • C22B19/22—Obtaining zinc otherwise than by distilling with leaching with acids
    • 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
    • C22B19/20—Obtaining zinc otherwise than by distilling
    • C22B19/26—Refining solutions containing zinc values, e.g. obtained by leaching zinc ores
    • 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
    • C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
    • C22B7/006—Wet processes
    • C22B7/007—Wet processes by acid leaching
    • 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
    • C22B7/00—Working up raw materials other than ores, e.g. scrap, to produce non-ferrous metals and compounds thereof; Methods of a general interest or applied to the winning of more than two metals
    • C22B7/04—Working-up slag
    • 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

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Inorganic Chemistry (AREA)
  • Metallurgy (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Processing Of Solid Wastes (AREA)

Abstract

The invention discloses a method for recycling electric furnace ash, belonging to the technical field of metallurgical solid waste and hazardous waste disposal. Then a series of methods such as sulfuric acid leaching, purification, magnetic separation, physical precipitation, electrolysis or evaporative concentration and the like are sequentially adopted to synchronously recycle and obtain high-value products such as iron oxide red, zinc ferrite, zinc oxide, basic zinc carbonate, zinc ingots or zinc sulfate and the like from the electric furnace ash, and the products can be sold as high-quality products, so that the recycling and high-value recycling of iron and zinc in the electric furnace ash are realized, the economic benefit is improved to the maximum extent, and the recycling treatment of hazardous wastes is realized.

Description

Electric furnace ash recycling treatment method
Technical Field
The invention belongs to the technical field of metallurgical solid waste recycling treatment, and particularly relates to a recycling treatment method for electric furnace ash.
Background
The electric furnace dust is the dust generated in the steelmaking production process of the steelmaking electric arc furnace, and in the smelting process of the electric arc furnace, low-boiling-point metals such as zinc, lead and the like in steelmaking materials are evaporated at high temperature and are taken out of the furnace body along with rising hot air flow, oxidized, vulcanized or chlorinated in a dust collection system, and then deposited in a dust collector to be collected to obtain the electric furnace dust. The electric furnace generally adopts scrap steel as a smelting raw material, about 15-25 kg of electric furnace ash is generated by smelting one ton of scrap steel, the main components of the electric furnace ash are iron and zinc, the iron content is about 20-40%, the zinc content is 7-40% (wherein about 50% of zinc exists in the form of insoluble zinc ferrite), and in addition, heavy metals such as cadmium, lead, nickel, chromium, manganese and the like with higher concentration are contained, so that the electric furnace ash is classified as hazardous waste by China and most developed countries (national hazardous waste records (2021 edition) waste code: HW 23).
At present, the main treatment methods of the electric furnace ash are pyrogenic treatment and wet treatment. The mainstream process of the pyrogenic process treatment is a rotary kiln, electric furnace ash is subjected to high-temperature reduction roasting at 1100-1300 ℃, and zinc volatilizes into smoke in the form of zinc steam and is collected. The method mainly recovers zinc resources, and has high reaction temperature and high energy consumption; the obtained zinc oxide has low grade, high content of heavy metals (lead, cadmium and the like) and low economic value; in order to reduce the ring formation fault of equipment caused by high iron content, zinc-containing minerals with low iron content are mixed in the rotary kiln treatment process to dilute iron, and in addition, the mixing amount of a reducing agent (coal dust or coke) is high (30-50%) in the treatment process, so that the iron content in the residual residues after treatment is low, the zinc content and the sulfur content are high, and the residual residues cannot be directly used as iron-making raw materials, meanwhile, the residual residues are hard solid solutions formed after high-temperature calcination, the conventional ore grinding and magnetic separation method is difficult to recover iron, most of the residual residues can only be discarded, and the waste of iron resources is caused.
The wet treatment mainly comprises an acid leaching method, an alkali leaching method and an ammonia leaching method, no matter which leaching method is adopted, zinc ferrite in the electric furnace dust cannot be dissolved, the recovery rate of zinc is low, and the zinc ferrite can only enter tailings, so that the waste of the zinc ferrite is caused. About 50% of zinc in the electric furnace dust exists in the form of insoluble zinc ferrite, the zinc ferrite is an important soft magnetic material and is a very representative catalyst for the oxidative dehydrogenation of alkene organic compounds, and meanwhile, the zinc ferrite has high photocatalytic activity and a semiconductor catalyst sensitive to visible light, and has the advantages of heat resistance, light resistance, no toxicity, rust prevention and the like. The current disposal idea is to reduce and roast zinc ferrite at high temperature to decompose into iron oxide and zinc oxide, then extract the zinc oxide by wet leaching, improve the recovery rate of zinc, and the methods do not effectively recover the zinc ferrite, thereby causing the waste of the zinc ferrite. On the other hand, because organic matters such as dioxin, polycyclic aromatic hydrocarbon and the like, chlorine compounds and fluorides exist in the ash of the electric furnace, and the organic matters such as the dioxin, the polycyclic aromatic hydrocarbon and the like enter the leaching solution, the faults such as burning loss of a circuit board in the subsequent electrolytic process can be caused, the flow of an electrolytic point is increased, and the cost is increased. If fluorine and chlorine ions enter the solution along with the leaching of zinc oxide, the fluorine ions corrode the cathode plate, so that the zinc sheet is difficult to strip, and the chlorine ions corrode the anode plate and the cooling tower, thereby bringing a series of difficulties in production and increasing the cost. Therefore, a method for removing or reducing organic matters in the electric furnace dust, synchronously recycling iron, zinc and zinc ferrite and disposing the electric furnace dust in a green and resource manner is needed to be developed.
Disclosure of Invention
In view of the above, the invention aims to provide a method for recycling electric furnace dust, which is used for solving the problems that iron and zinc ferrite in the electric furnace dust cannot be recycled, the recovery rate of zinc is low, and resource waste is caused.
The invention is realized by the following technical scheme:
the invention provides a method for recycling electric furnace ash, which mainly comprises the following steps:
1) oxidizing and roasting: introducing oxygen at a temperature which is enough to decompose and volatilize organic matters such as dioxin, polycyclic aromatic hydrocarbon, tar and the like, fluoride and chloride in the electric furnace ash but not enough to volatilize zinc, oxidizing and roasting the electric furnace ash, decomposing the fluoride and the chloride with low boiling points into gaseous state under the high-temperature oxidation condition, and removing the gaseous state along with the flue gas entering a flue gas dust removal device, wherein the organic matters are decomposed into substances such as carbon dioxide, water and the like to be removed;
2) acid leaching:
primary leaching: adopting 10-15% of sulfuric acid, and mixing the sulfuric acid and the electric furnace ash according to the solid-liquid mass-volume ratio of 125kg/m3-250kg/m3Mixing, primary leaching under stirring or grinding condition to dissolve soluble substances such as iron oxide, zinc oxide, etc. in the electric furnace ash into leaching solution for 1-2h, and filtering the solid-liquid mixture after primary leaching to obtain primary leaching residue and primary leaching solution. Keeping the reaction temperature at 45-80 ℃ in the leaching process;
secondary leaching: performing secondary leaching on the primary leaching residue under the same condition as the primary leaching, further dissolving soluble substances such as iron oxide, zinc oxide and the like in the primary leaching residue into a leaching solution, filtering after the secondary leaching is finished to obtain a secondary leaching solution and secondary leaching residue, returning the secondary leaching solution to the primary leaching process for circularly enriching iron and zinc, and feeding the secondary leaching residue into a zinc ferrite separation process;
3) separating zinc ferrite: washing the secondary leaching residue obtained in the step 2) for 2 times by using tap water at the temperature of 50-80 ℃, carrying out magnetic separation on the leaching residue after washing, selling zinc ferrite obtained by magnetic separation as a product, and treating tailings as solid waste;
4) and (3) leachate purification and oxidation treatment: adding elemental iron powder as a purifying agent into the primary leachate obtained in the step 2), purifying the leachate under stirring for 20-60 min, filtering to obtain a purified liquid and purified slag, recycling the purified slag in a purification process, and oxidizing the purified liquid obtained after the purification process, wherein the oxidation process comprises blowing air into the leachate, and adding ammonium persulfate or H2O2Oxidizing bivalent iron in the purifying liquid into trivalent iron with oxidant and maintaining the reaction temperature at 50-80 deg.c during oxidation and purification;
5) depositing iron to obtain an iron oxide red product: under the condition that the temperature is 50-70 ℃,adding alkali (sodium hydroxide, ammonia water, etc.) into the oxidized purified solution obtained in the step 4), adjusting the pH of the purified solution to 2.8-3.3, and precipitating ferric iron to obtain Fe (OH)3Flocculent precipitate, then filtered to obtain filtrate and Fe (OH)3And (4) colloidal precipitation. Standing the colloidal precipitate for 30-60 min to separate the colloidal precipitate, separating the upper layer of colloidal precipitate from the bottom layer of mixed residue, washing the bottom layer of mixed residue with water, filtering, and treating as tailings; drying the upper layer colloidal precipitate, and calcining at the temperature of 700-900 ℃ to obtain an iron oxide red product;
6) and (3) zinc recovery: and (3) purifying and impurity removing treatment is carried out on the zinc-containing filtrate obtained in the step 5), impurity ions such as copper, nickel, chromium and the like in the solution and iron ions which are not precipitated after treatment in the step 5) are removed. After the purification and impurity removal reaction is finished, filtering to obtain a purified zinc-containing solution and purified slag, sampling and testing the purified solution after filtering, if the content of heavy metals except zinc in the solution is less than 2g/L, the purified solution is qualified, then sending the qualified purified solution to a zinc recovery process, and obtaining zinc-containing products such as zinc ingots, zinc sulfate, basic zinc carbonate or zinc oxide by electrolysis, evaporation concentration or adding a precipitator.
Preferably, the oxidizing roasting temperature range in the step 1) is as follows: 400 ℃ and 800 ℃, and the roasting time is 10-40 min.
Preferably, the purification and impurity removal treatment method in the step 6) comprises one or a combination of two methods of zinc powder replacement and sulfide vulcanization.
Preferably, the zinc recovery process of step 6) comprises one or a combination of two methods of chemical precipitation (precipitating agent including carbonate, bicarbonate), electrolysis, and evaporative concentration.
The invention has the beneficial effects that:
1. the invention discloses a method for recycling electric furnace ash, which adopts a series of methods such as oxidizing roasting, acid leaching, purifying, magnetic separation, physical precipitation, electrolysis or evaporation concentration and the like to synchronously recycle high-value products such as iron oxide red, zinc ferrite, zinc sulfate, zinc oxide, basic zinc carbonate or zinc ingots and the like from the electric furnace ash, and the products can be sold as high-quality products, thereby realizing the recycling and high-value recycling of iron and zinc in the electric furnace ash, improving the economic benefit to the maximum extent and realizing the recycling treatment of hazardous wastes.
2. The invention discloses a method for recycling electric furnace ash, which comprises the steps of firstly carrying out oxidizing roasting on the electric furnace ash at a low temperature to remove organic matters and most of chlorides and fluorides in the electric furnace ash, and reducing the harmful influence of the organic matters, the chlorides and the fluorides on a subsequent production process. Compared with the traditional dedusting ash washing pretreatment scheme, the method has the advantages that through oxidizing roasting, the chloride and the fluoride in the electric furnace ash are thoroughly removed, meanwhile, the organic matters in the electric furnace ash are also removed, and the influence of the organic matters, the chloride and the fluoride on subsequent wet treatment is reduced.
3. The invention discloses a recycling treatment method of electric furnace ash, which treats the electric furnace ash by a series of methods such as oxidizing roasting, acid leaching, purification, magnetic separation, physical precipitation, electrolysis or evaporation concentration and the like, and can realize the recovery rate of soluble iron of more than 80 percent and the recovery rates of zinc and zinc ferrite of more than 70 percent respectively. Realizes the reclamation and high-valued treatment of the hazardous waste
Drawings
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings. Wherein:
FIG. 1 is a flow chart of a method for recycling electric furnace ash according to the present invention.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention in a schematic way, and the features in the following embodiments and examples may be combined with each other without conflict.
The basic flow of the electric furnace ash recycling method in each embodiment of the invention is shown in fig. 1, and comprises the following steps:
1) oxidizing and roasting: under the temperature condition of 400 plus materials and 800 ℃, oxygen is introduced to carry out oxidizing roasting on the electric furnace ash for 10-40min, so that the fluoride and the chloride with low boiling point are decomposed into gaseous state and enter a flue gas dust removal device along with the flue gas to be removed, and the organic matters are decomposed into substances such as carbon dioxide, water and the like to be removed.
2) Acid leaching:
primary leaching: adopting 10-15% of sulfuric acid, and mixing the sulfuric acid and the electric furnace ash according to the solid-liquid mass-volume ratio of 125kg/m3-250kg/m3Mixing, primary leaching under stirring or grinding condition to dissolve soluble substances such as iron oxide, zinc oxide, etc. in the electric furnace ash into leaching solution for 1-2h, and filtering the solid-liquid mixture after primary leaching to obtain primary leaching residue and primary leaching solution. The reaction temperature is kept between 45 and 80 ℃ during the leaching process.
Secondary leaching: and (3) carrying out secondary leaching on the primary leaching residue under the same condition as the primary leaching, further dissolving soluble substances such as iron oxide, zinc oxide and the like in the primary leaching residue into a leaching solution, filtering after the secondary leaching is finished to obtain a secondary leaching solution and secondary leaching residue, returning the secondary leaching solution to the primary leaching process for circularly enriching iron and zinc, and sending the secondary leaching residue to a zinc ferrite separation process.
3) Separating zinc ferrite: washing the secondary leaching residue obtained in the step 2) for 2 times by using tap water at 50-80 ℃, carrying out magnetic separation on the leaching residue after washing, selling zinc ferrite obtained by magnetic separation as a product, and treating tailings as solid waste.
4) And (3) leachate purification and oxidation treatment: adding simple substance iron powder as a purifying agent into the primary leaching solution obtained in the step 2), and purifying the leaching solution under stirring for 20-60 min; after purification treatment, the mixture is filtered to obtain purified liquid and purified slag, and the purified slag can be returned to the purification process for recycling. After the purification treatment is finished, the purified liquid obtained by the purification treatment is subjected to oxidation treatment, and the oxidation treatment method comprises the step of adding the leachate into the leachateBlowing air, adding ammonium persulfate or H2O2Oxidizing agent to oxidize the ferrous iron in the purifying liquid into ferric iron. The reaction temperature is kept between 50 and 80 ℃ in the oxidation and purification treatment processes.
5) Depositing iron to obtain an iron oxide red product: adding alkali (sodium hydroxide, ammonia water, etc.) into the oxidized purified liquid obtained in the step 4) at the temperature of 50-70 ℃, adjusting the pH value to 2.8-3.3, and precipitating ferric iron to obtain Fe (OH)3Flocculent precipitate, then filtered to obtain filtrate and Fe (OH)3And (4) colloidal precipitation. Standing the colloidal precipitate for 30-60 min to separate the colloidal precipitate, separating the upper layer of colloidal precipitate from the bottom layer of mixed residue, washing the bottom layer of mixed residue with water, filtering, and treating as tailings; drying the upper layer colloidal precipitate, and calcining at the temperature of 700-900 ℃ to obtain the iron oxide red product.
6) And (3) zinc recovery: and (3) purifying and impurity removing treatment is carried out on the zinc-containing filtrate obtained in the step 5), impurity ions such as copper, nickel, chromium and the like in the solution and iron ions which are not precipitated after the treatment in the step 5) are removed, and the purifying and impurity removing treatment method comprises one or two methods of zinc powder replacement and sulfide vulcanization. After the purification and impurity removal reaction is finished, filtering to obtain a purified zinc-containing solution and purified slag, sampling and testing the purified solution after filtering, if the content of heavy metals except zinc in the solution is less than 2g/L, the purified solution is qualified, then sending the qualified purified solution to a zinc recovery process, and obtaining zinc-containing products such as zinc ingots, zinc sulfate, zinc oxide or basic zinc carbonate by electrolysis, evaporation concentration or addition of a precipitator such as carbonate, bicarbonate and the like.
So far, the electric furnace ash is recycled to obtain zinc-containing products such as zinc ferrite, iron oxide red, zinc ingots, zinc oxide or basic zinc carbonate and the like, so that the recovery rate of soluble iron in the electric furnace ash is more than 80 percent, and the recovery rates of zinc and zinc ferrite are both more than 70 percent. And the recovered product has high economic value, can be sold as a high-quality product, realizes the recycling and high-value recovery of iron and zinc in the electric furnace dust, improves the economic benefit to the maximum extent, and realizes the recycling treatment of hazardous wastes.
The technical effects of the present invention will be further described with reference to the following examples having specific configurations.
Example one
The embodiment of the invention provides a method for recycling electric furnace ash, which comprises the following steps of:
1) oxidizing and roasting: the electric furnace ash is sent into a rotary roasting furnace, oxygen is introduced into the furnace, the electric furnace ash is oxidized and roasted under the conditions of 400-450 ℃, the roasting time is 30-40min, fluoride and chloride with low boiling point are decomposed into gas, the gas enters a cloth bag dust removal system along with flue gas and is removed, and organic matters are decomposed into substances such as carbon dioxide, water and the like and are removed.
2) Acid leaching: cooling the oxidized and roasted electric furnace ash to about 100 ℃ by air cooling, and then mixing the cooled electric furnace ash with 10% sulfuric acid according to the solid-liquid mass-volume ratio of 125kg/m3-150kg/m3Mixing the raw materials according to the proportion, uniformly stirring, conveying the mixed slurry into a wet ball mill by using a pump to grind and leach for the first time so as to dissolve soluble substances such as iron oxide, zinc oxide and the like in electric furnace ash into a sulfuric acid solution, wherein the grinding and leaching time is 1h, and after the primary leaching is finished, filtering a solid-liquid mixture to obtain primary leaching residue and primary leaching liquid, wherein the total iron concentration in the primary leaching liquid is 19.7g/L, and the zinc concentration in the primary leaching liquid is 29 g/L. And introducing steam into the ball mill during the leaching process to keep the reaction temperature at 45-50 ℃. Under the same conditions as in the primary leaching (10% sulfuric acid, solid-liquid mass-to-volume ratio of 125 kg/m)3-150kg/m3And the reaction temperature is 45-50 ℃), mixing and stirring the primary leaching residue and a 10% sulfuric acid solution for 30min for secondary leaching, further dissolving soluble substances such as iron oxide, zinc oxide and the like in the primary leaching residue into a leaching solution, filtering after the secondary leaching is finished to obtain a secondary leaching solution and secondary leaching residue, returning the secondary leaching solution to the primary leaching process as the leaching solution to circularly enrich iron and zinc, and feeding the secondary leaching residue into a zinc ferrite separation process.
3) Separating zinc ferrite: the secondary leaching slag is treated with tap water at 70-80 ℃ in a solid-liquid mass-volume ratio of 150kg/m3-200kg/m3Mixing the raw materials according to the proportion, stirring for 30min for primary washing, filtering after the primary washing to obtain primary washing liquid and primary washing slag, and returning the primary washing liquid to the acid leaching process to be used as a preparation liquid of a sulfuric acid solutionMixing and stirring water, primary washing slag and normal-temperature tap water for 10min for secondary washing, feeding the mixed liquid of the secondary washing into a magnetic separator, carrying out magnetic separation to obtain a zinc ferrite product with the purity of 70%, and treating magnetic separation tailings as solid waste.
4) And (3) leachate purification and oxidation treatment: introducing steam into the primary leachate obtained in the acid leaching process to keep the temperature of the solution at 50-60 ℃, adding simple substance iron powder serving as a purifying agent into the leachate, and stirring for 20-30min to perform purification treatment; and filtering after purification treatment to obtain purified liquid and purified slag, wherein the purified slag is used as a purifying agent for recycling twice and then is sold as metal slag. And after the purification treatment is finished, blowing air into the purified liquid obtained by the purification treatment for 2-3h to oxidize the ferrous iron in the purified liquid into ferric iron.
5) Depositing iron to obtain an iron oxide red product: adding sodium hydroxide into the oxidized purified liquid obtained in the step 4) at the temperature of 50-60 ℃, adjusting the pH of the purified liquid to about 2.8, and precipitating to obtain Fe (OH)3Flocculent precipitate, then filtered to obtain filtrate and Fe (OH)3And (4) colloidal precipitation. Standing the colloidal precipitate for 30min to layer the colloidal precipitate, separating the upper layer colloidal precipitate and the bottom layer mixed residue with a liquid separating device, and washing the bottom layer mixed residue for 2 times to obtain tailings; drying the upper layer colloidal precipitate in a flash evaporation dryer, and calcining at 700 ℃ to obtain an iron oxide red product.
6) And (3) zinc recovery: introducing steam into the zinc-containing filtrate obtained in the step 5) after the iron precipitation, and keeping the temperature of the solution at 40-50 ℃. And then adding sodium sulfide into the solution, stirring for 20min, filtering to obtain filter residue and filtrate, adding zinc powder into the filtrate, stirring for 20-25min, filtering to obtain a purified zinc-containing solution and purified residue, taking the filtered purified solution, and testing, wherein the content of heavy metals except zinc in the solution is 1.6g/L and less than 2g/L, and the purified solution is qualified. And (3) feeding the qualified purified solution into an electrolytic bath for electrolysis to obtain elemental zinc, and carrying out fusion casting treatment on the elemental zinc to obtain a zinc ingot product.
Example two
The embodiment of the invention provides a method for recycling electric furnace ash, which comprises the following steps of:
1) oxidizing and roasting: the electric furnace ash is sent into a rotary roasting furnace, oxygen is introduced into the rotary roasting furnace, the electric furnace ash is oxidized and roasted under the condition of 750-800 ℃, the roasting time is 10-20min, fluoride and chloride with low boiling point are decomposed into gas, the gas enters a cloth bag dust removal system along with the flue gas and is removed, and organic matters are decomposed into substances such as carbon dioxide, water and the like and are removed.
2) Acid leaching: naturally cooling the oxidized and roasted electric furnace ash to about 100 ℃, and then mixing the electric furnace ash with 15 percent sulfuric acid according to the solid-liquid mass-volume ratio of 200kg/m3-250kg/m3Mixing the raw materials according to the proportion, stirring for 2h, and leaching for the first time to dissolve soluble substances such as iron oxide, zinc oxide and the like in the electric furnace ash into a sulfuric acid solution. And after the primary leaching is finished, filtering the solid-liquid mixture to obtain primary leaching residue and primary leaching liquid, wherein the total iron concentration in the primary leaching liquid is 26.8g/L, and the zinc concentration in the primary leaching liquid is 27 g/L. The solution was electrically heated during the leaching process to maintain the reaction temperature at 70-80 ℃. Under the same conditions as in the primary leaching (15% sulfuric acid, solid-liquid mass-to-volume ratio of 200 kg/m)3-250kg/m3And the reaction temperature is 70-80 ℃), mixing and stirring the primary leaching residue and 15% sulfuric acid solution for 30min for secondary leaching, further dissolving soluble substances such as iron oxide, zinc oxide and the like in the primary leaching residue into leaching solution, filtering after the secondary leaching is finished to obtain secondary leaching solution and secondary leaching residue, returning the secondary leaching solution to the primary leaching process as leaching solution for circularly enriching iron and zinc, and feeding the secondary leaching residue into a zinc ferrite separation process.
3) Separating zinc ferrite: the secondary leaching slag is treated by tap water with the temperature of 50-60 ℃ and the solid-liquid mass-volume ratio of 200kg/m3-250kg/m3Mixing the raw materials according to the proportion, stirring for 40-50min for primary washing, filtering after the primary washing is finished to obtain primary washing liquid and primary washing slag, returning the primary washing liquid to the acid leaching process to be used as the solution preparation water of a sulfuric acid solution, mixing and stirring the primary washing slag and tap water with the temperature of 40-50 ℃ for 20min for secondary washing, filtering after the secondary washing is finished to obtain secondary washing liquid and secondary washing slag, returning the secondary washing liquid to a system to be used as the primary washing liquid, sending the secondary washing slag to a magnetic separator, and performing magnetic separation to obtain a zinc ferrite product with the purity of 72 percentAnd treating the magnetic separation tailings as solid waste.
4) And (3) leachate purification and oxidation treatment: heating primary leachate obtained in the acid leaching process to 70-80 ℃, adding simple substance iron powder serving as a purifying agent into the leachate, and stirring for 20-30min for purification treatment; and filtering after purification treatment to obtain purified liquid and purified slag, wherein the purified slag is used as a purifying agent for recycling twice and then is sold as metal slag. After the purification treatment was completed, ammonium persulfate was added to the purified solution obtained by the purification treatment, and the mixture was stirred for 1 hour to oxidize the divalent iron in the purified solution into trivalent iron.
5) Depositing iron to obtain an iron oxide red product: adding ammonia water into the oxidized purified liquid obtained in the step 4) at the temperature of 60-70 ℃, adjusting the pH of the purified liquid to about 3.3, and precipitating to obtain Fe (OH)3Flocculent precipitate, then filtered to obtain filtrate and Fe (OH)3And (4) colloidal precipitation. Standing the colloidal precipitate for 1h to layer the colloidal precipitate, separating the upper layer of the colloidal precipitate from the bottom layer of the mixed residue by a liquid separating device, and washing the bottom layer of the mixed residue for 2 times to obtain tailings for treatment; drying the upper layer colloidal precipitate in a flash evaporation dryer, and calcining at the temperature of 850-900 ℃ to obtain an iron oxide red product.
6) And (3) zinc recovery: electrically heating the zinc-containing filtrate obtained in the step 5) after iron precipitation, and keeping the temperature of the solution at 40-50 ℃. And adding zinc powder into the solution, stirring for 20-25min, filtering to obtain primary filtrate and primary filter residue, and testing the filtered purified solution to obtain a solution with the content of heavy metals except zinc of about 3g/L and more than 2 g/L. And adding ammonium sulfide into the filtered filtrate, stirring for 20min, filtering to obtain a secondary filtrate and a secondary filter residue, adding zinc powder into the secondary filtrate, stirring for 20-25min, filtering to obtain a purified zinc-containing solution and a purified residue, taking the filtered purified solution, and testing, wherein the content of heavy metals except zinc in the solution is 1.2g/L and less than 2g/L, and the purified solution is qualified. And (2) sending the qualified purified liquid into a crystallization reactor, then adding ammonium bicarbonate into the crystallization reactor, stirring for 30min for reaction to obtain basic zinc carbonate precipitate, filtering to obtain basic zinc carbonate and ammonium sulfate solution, washing the basic zinc carbonate with demineralized water for 2 times, filtering, drying at 100 ℃ to obtain a basic zinc carbonate product, and further calcining the basic zinc carbonate product to obtain a zinc oxide product. Finally, evaporating and crystallizing the ammonium sulfate solution to obtain an ammonium sulfate byproduct.
EXAMPLE III
The embodiment of the invention provides a method for recycling electric furnace ash, which comprises the following steps of:
1) oxidizing and roasting: the electric furnace ash is sent into a rotary roasting furnace, oxygen is introduced into the furnace, the electric furnace ash is oxidized and roasted under the conditions of 500-600 ℃, the roasting time is 20-30min, fluoride and chloride with low boiling point are decomposed into gas, the gas enters a cloth bag dust removal system along with flue gas and is removed, and organic matters are decomposed into substances such as carbon dioxide, water and the like and are removed.
2) Acid leaching: naturally cooling the oxidized and roasted electric furnace ash to about 100 ℃, and then mixing the electric furnace ash with 12 percent sulfuric acid according to the solid-liquid mass-volume ratio of 150kg/m3-200kg/m3The mixture is stirred for 1.5h for primary leaching, so that soluble substances such as iron oxide, zinc oxide and the like in the electric furnace ash are dissolved into a sulfuric acid solution. And after the primary leaching is finished, filtering the solid-liquid mixture to obtain primary leaching residues and primary leaching liquid. The solution was electrically heated during the leaching process to maintain the reaction temperature at 50-60 ℃. Under the same conditions as in the primary leaching (12% sulfuric acid, solid-liquid mass-to-volume ratio of 150 kg/m)3-200kg/m3And the reaction temperature is 50-60 ℃), mixing and stirring the primary leaching residue and a 12% sulfuric acid solution for 30min for secondary leaching, further dissolving soluble substances such as iron oxide, zinc oxide and the like in the primary leaching residue into a leaching solution, filtering after the secondary leaching is finished to obtain a secondary leaching solution and secondary leaching residue, returning the secondary leaching solution to the primary leaching process as the leaching solution to circularly enrich iron and zinc, and feeding the secondary leaching residue into a zinc ferrite separation process.
3) Separating zinc ferrite: the secondary leaching slag is treated by tap water with the temperature of 50-60 ℃ and the solid-liquid mass-volume ratio of 200kg/m3-250kg/m3Mixing the raw materials in proportion, stirring for 40-50min for primary washing, filtering after the primary washing to obtain primary washing liquid and primary washing slag, and returning the primary washing liquid to the acid leaching process as sulfuric acid solutionMixing and stirring the primary washing slag and tap water with the temperature of 40-50 ℃ for 20min to carry out secondary washing, filtering after the secondary washing is finished to obtain secondary washing liquid and secondary washing slag, returning the secondary washing liquid to a system to be used as the primary washing liquid, sending the secondary washing slag to a magnetic separator, carrying out magnetic separation to obtain a zinc ferrite product with the purity of 70%, and treating magnetic separation tailings as solid waste.
4) And (3) leachate purification and oxidation treatment: heating primary leachate obtained in the acid leaching process to 50-60 ℃, adding simple substance iron powder serving as a purifying agent into the leachate, and stirring for 20-30min for purification treatment; and filtering after purification treatment to obtain purified liquid and purified slag, wherein the purified slag is used as a purifying agent for recycling twice and then is sold as metal slag. After the purification treatment was completed, ammonium persulfate was added to the purified solution obtained by the purification treatment, and the mixture was stirred for 1.5 hours to oxidize the ferrous iron in the purified solution into ferric iron.
5) Depositing iron to obtain an iron oxide red product: adding sodium hydroxide into the oxidized purified liquid obtained in the step 4) at the temperature of 50-60 ℃, adjusting the pH of the purified liquid to about 3.0, and precipitating to obtain Fe (OH)3Flocculent precipitate, then filtered to obtain filtrate and Fe (OH)3And (4) colloidal precipitation. Standing the colloidal precipitate for 1h to layer the colloidal precipitate, separating the upper layer of the colloidal precipitate from the bottom layer of the mixed residue by a liquid separating device, and washing the bottom layer of the mixed residue for 2 times to obtain tailings for treatment; drying the upper layer colloidal precipitate in a flash evaporation dryer, and calcining at the temperature of 700-7500 ℃ to obtain an iron oxide red product.
6) And (3) zinc recovery: electrically heating the zinc-containing filtrate obtained in the step 5) after iron precipitation, and keeping the temperature of the solution at 50-60 ℃. And adding zinc powder into the solution, stirring for 20-25min, filtering to obtain primary filtrate and primary filter residue, taking the filtered purified solution, and testing, wherein the content of heavy metals except zinc in the solution is about 1.95g/L and less than 2g/L, and the purified solution is qualified. And (3) feeding the qualified purified solution into an electrolytic bath for electrolysis to obtain elemental zinc, and carrying out fusion casting treatment on the elemental zinc to obtain a zinc ingot product. Feeding the electrolysis residual liquid into an evaporator, introducing steam with the temperature of 150 ℃ into the evaporator, and evaporating and concentrating to obtain a zinc sulfate product containing sodium sulfate and other miscellaneous salts.
Finally, the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the claims of the present invention.

Claims (4)

1. The electric furnace ash recycling method is characterized by comprising the following steps:
1) oxidizing and roasting: introducing oxygen at a temperature which is enough to decompose and volatilize organic matters such as residual dioxin, polycyclic aromatic hydrocarbon, tar and the like, fluoride and chloride in the electric furnace ash but not enough to volatilize zinc, and oxidizing and roasting the electric furnace ash;
2) acid leaching:
a. primary leaching: adopting 10-15% of sulfuric acid, and roasting the sulfuric acid and the electric furnace ash obtained in the step 1) according to the solid-liquid mass-volume ratio of 125kg/m3-250kg/m3Mixing, and performing primary leaching under stirring or grinding conditions for 1-2h, keeping the reaction temperature at 45-80 deg.C during the leaching process, and filtering to obtain primary leachate and primary leaching residue after the reaction;
b. secondary leaching: performing secondary leaching on the primary leaching residue under the same condition as the primary leaching, filtering after the secondary leaching is finished to obtain a secondary leaching solution and secondary leaching residue, returning the secondary leaching solution to the primary leaching process for recycling, and sending the secondary leaching residue to a zinc ferrite separation process;
3) separating zinc ferrite: washing the secondary leaching residue obtained in the step 2) with tap water at 50-80 ℃ for 2 times, carrying out magnetic separation on the washed leaching residue, selling zinc ferrite as a product obtained by magnetic separation, and treating tailings as solid waste;
4) and (3) leachate purification and oxidation treatment: adding simple substance iron powder as a purifying agent into the primary leaching solution obtained in the step 2), and purifying the leaching solution, wherein the purifying reaction is carried out under the stirring condition, and the reaction time is 20-60 min; filtering to obtain purified liquid and purifyingThe slag and the purification slag can be returned to the purification process for recycling, and after the purification treatment is finished, the purification liquid obtained by the purification treatment is subjected to oxidation treatment, and the oxidation treatment method comprises the following steps: blowing air into the leachate, and adding ammonium persulfate or H2O2And the like. Keeping the reaction temperature at 50-80 ℃ in the oxidation and purification treatment processes;
5) depositing iron to obtain an iron oxide red product: adding alkali into the oxidized purified liquid obtained in the step 4) at the temperature of 50-70 ℃, adjusting the pH of the purified liquid to 2.8-3.3, and precipitating ferric iron to obtain Fe (OH)3Flocculent precipitate, then filtered to obtain filtrate and Fe (OH)3Carrying out colloidal precipitation, standing the colloidal precipitation for 30-60 min to separate the colloidal precipitation into layers, separating the upper-layer colloidal precipitation from the bottom-layer mixed slag, washing and filtering the bottom-layer mixed slag, and treating the bottom-layer mixed slag as tailings; drying the upper layer colloidal precipitate, and calcining at the temperature of 700-900 ℃ to obtain an iron oxide red product;
6) and (3) zinc recovery: and (3) purifying and impurity removing the zinc-containing filtrate obtained in the step 5), filtering to obtain a purified zinc-containing solution and purified slag, testing the purified solution after the purification treatment, if the content of heavy metals except zinc in the solution is less than 2g/L, determining that the purified solution is qualified, then sending the qualified purified solution to a zinc recovery process, and obtaining zinc-containing products such as zinc ingots, zinc sulfate, basic zinc carbonate or zinc oxide by electrolysis, evaporation concentration or adding a precipitator.
2. The method as claimed in claim 1, wherein the oxidizing roasting temperature in step 1) is in the range of: 400 ℃ and 800 ℃, and the roasting time is 10-40 min.
3. The method as claimed in claim 1, wherein the purification and impurity removal treatment method in step 6) comprises one or two methods of zinc powder replacement and sulfide vulcanization.
4. The method of claim 1, wherein the zinc recovery process of step 6) comprises using one or a combination of chemical precipitation (precipitant comprises carbonate, bicarbonate), electrolysis, and evaporative concentration.
CN202210031344.3A 2022-01-12 2022-01-12 Electric furnace ash recycling treatment method Pending CN114350935A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210031344.3A CN114350935A (en) 2022-01-12 2022-01-12 Electric furnace ash recycling treatment method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210031344.3A CN114350935A (en) 2022-01-12 2022-01-12 Electric furnace ash recycling treatment method

Publications (1)

Publication Number Publication Date
CN114350935A true CN114350935A (en) 2022-04-15

Family

ID=81109993

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210031344.3A Pending CN114350935A (en) 2022-01-12 2022-01-12 Electric furnace ash recycling treatment method

Country Status (1)

Country Link
CN (1) CN114350935A (en)

Similar Documents

Publication Publication Date Title
CN111172412B (en) Method for extracting manganese and comprehensively recovering nickel, cobalt and copper by cobalt-manganese multi-metal oxide ore dressing and smelting
CN113684368A (en) Method for co-processing arsenic sulfide slag and arsenic-containing smoke dust in copper smelting
CN110643815B (en) Recycling harmless treatment method for black copper mud
CN110564970A (en) Process method for recovering potassium, sodium and zinc from blast furnace cloth bag ash
WO2019148901A1 (en) Method for treating chromium slag by chlorinating calcination in combination with hydrothermal mineralization
CN110775998A (en) System and method for producing nano zinc oxide by industrially recycling zinc
AU710302B2 (en) Method for recovering metal and chemical values
US5759503A (en) Method for the further purification of zinc oxide
CN113862464B (en) Method for recovering copper and scattered metal in black copper sludge
CN110863219B (en) Method for resource utilization of zinc-containing converter dust and sludge
US6517789B1 (en) Method for reclaiming constituents from an industrial waste stream
CN110055425B (en) Electroplating sludge heavy metal recycling method
US6696029B1 (en) Method for the purification of zinc oxide controlling particle size
CN109055764B (en) Comprehensive recovery method of high-chlorine low-zinc material
CN111593205A (en) Method for recovering cobalt from cobalt-containing sulfuric acid residue
EP0783593B1 (en) Method for recovering metal and chemical values
CN114934169B (en) Method for recycling tungsten-containing waste
CN114350935A (en) Electric furnace ash recycling treatment method
CN114006067B (en) Method and system for recycling anode and cathode mixed powder of waste ternary lithium ion battery
CN216514040U (en) System for recovering copper, nickel, zinc, chromium and iron from electroplating sludge or other multi-metal mixture
CN114558440A (en) Process for efficiently extracting zinc by high-chlorine zinc ash ammonia-ammonium sulfate method and flue gas desulfurization and carbon fixation by coupled slurry method
CN111876607B (en) Leaching, enriching and separating process for iron and chromium elements in electric furnace dust
KR100236663B1 (en) Method for recovering metal and chemical values
CN111575500A (en) Method for treating zinc-containing dangerous solid waste and zinc ore by combining chlorination roasting with ammonia process electrodeposition
CN115505751B (en) Method for enriching germanium and indium from copper sulfide ore and co-producing blister copper

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination