Method for preparing zinc carbonate and zinc ferrite from regenerated steel electric furnace ash based on bioleaching selective zinc extraction

Abstract

The invention provides a method for preparing zinc carbonate and zinc ferrite from regenerated steel electric furnace ash based on bioleaching selective zinc extraction, which comprises the following steps: continuously preparing active bioleaching by using a membrane bioreactor, adding a complexing agent or a solubilizer with a certain concentration, and controlling the pH value range in a step system to obtain zinc carbonate and zinc ferrite. Soluble zinc in the regenerated steel electric furnace ash can be effectively and selectively leached, and generation of precipitates such as calcium sulfate, magnesium sulfate and lead sulfate in leached residues is inhibited; a zinc carbonate product can be prepared after impurity removal and precipitation of the zinc-rich leachate, and resource utilization of the regenerated iron and steel electric furnace ash is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of solid waste resource utilization, and specifically relates to a method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash based on bioleaching and selective zinc extraction. Background Art

[0002] The annual output of my country's recycled steel industry exceeds 200 million tons, accounting for about 20% of the country's total steel production. The short-process smelting of recycled steel produces a large amount of electric furnace ash, which contains about 20% zinc and a small amount of toxic metals such as nickel, chromium, and lead. It is listed as a hazardous waste (No. 312-001-31) and is a high-zinc hazardous waste, which is strictly supervised by the ecological and environmental departments. According to incomplete statistics, the annual output of electric furnace ash in my country's recycled steel industry exceeds 1 million tons. Due to its large output, small particle size, high activity, and wide distribution, electric furnace ash poses a major threat to the regional environment and human health. The resource utilization of electric furnace ash is of great significance to the control of toxic metal pollution, the recycling of valuable metals, and the sustainable development of the recycled steel industry.

[0003] At present, pyrometallurgical zinc extraction is a common process for separating and recovering zinc from high-zinc materials, including rotary hearth furnaces and rotary kilns. However, pyrometallurgical zinc extraction can usually only obtain a zinc recovery rate of 80%-85%, and the secondary zinc oxide recovered is a low-priced by-product. In addition, it requires high temperature conditions of 1250°C and a strict flue gas treatment system. In recent years, under the background of "dual carbon", the pyrometallurgical zinc extraction process has been increasingly challenged by problems such as high energy consumption, high carbon emissions and high flue gas treatment costs. At the same time, due to its low energy consumption, high zinc extraction rate, flexible process, strong material adaptability, and the recovery of high-purity zinc-based products, the wet zinc extraction process has demonstrated greater application prospects in the resource utilization of zinc-containing solid waste, especially for high-zinc hazardous waste with high material dispersion and advocated on-site disposal.

[0004] At present, the zinc in recycled steel electric furnace ash cannot be effectively extracted and utilized as a resource, and the processing method has high energy consumption and its environmental protection needs to be improved. Summary of the invention

[0005] The present invention provides a method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching, which is used to solve the problem that zinc in electric furnace ash cannot be effectively utilized as a resource in the prior art.

[0006] The present invention provides a method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching, characterized in that it comprises the following steps: (1) adding energy substrate to the membrane bioreactor, inoculating at least one of sulfur oxidizing bacteria, iron oxidizing bacteria, or a composite bacterial group of sulfur oxidizing bacteria and iron oxidizing bacteria for cultivation, and obtaining active biological leachate through membrane extraction; (2) adding recycled steel electric furnace ash and at least one of a chelating agent or a solubilizing agent to the active biological leachate, and performing a first leaching treatment in sequence, and obtaining a zinc-containing leaching solution and zinc ferrite leaching residue after solid-liquid separation; (3) returning the zinc-containing leachate to the membrane bioreactor for regeneration until the pH value of the system is between 0.8 and 1.0 to obtain regenerated leachate; (4) adding regenerated steel electric furnace ash to the regenerated leachate for cyclic leaching treatment, and obtaining zinc-rich leaching solution and zinc ferrite leaching slag after solid-liquid separation; (5) adding hydrogen peroxide and sodium hydroxide solution to the zinc-rich leaching solution until the pH value of the system is 5.0-6.0, performing purification treatment, and obtaining a zinc-rich purified solution after solid-liquid separation; (6) Sodium carbonate is added to the zinc-rich purified liquid until the pH value of the system is 8.0-8.5, and zinc extraction is performed to obtain a zinc carbonate product after solid-liquid separation.

[0007] Compared with the prior art, the advantages of the present invention are as follows: by using the active biological leachate continuously prepared by the membrane bioreactor and adding a certain concentration of a chelating agent or a solubilizing agent, the pH range in the step system is controlled, so that the soluble zinc in the recycled steel electric furnace ash can be effectively selectively leached, and the formation of precipitates such as calcium sulfate, magnesium sulfate and lead sulfate in the leached slag can be inhibited; and a zinc carbonate product can be prepared by removing impurities and precipitating the zinc-rich leachate, thereby realizing the resource utilization of the recycled steel electric furnace ash.

[0008] Furthermore, the pH value of the active biological leachate is 0.5~1.0, Fe 2+ The concentration is 0.25~0.5g / L, Fe 3+ The concentration is 0.5~1.0 g / L, the organic acid concentration is 150~300 mg / L, and the extracellular polymer concentration is 250-500 mg / L.

[0009] Furthermore, in the first extraction process and / or the cyclic extraction process, the solid-liquid ratio is 10-20%, the extraction temperature is 25-40° C., the stirring speed is 20-60 rpm, and the extraction time is 1.5-4.0 h.

[0010] Furthermore, the hydraulic retention time of the regeneration treatment is 24 to 96 hours.

[0011] Furthermore, the amount of hydrogen peroxide added is 0.1-0.2% by volume of the zinc-rich leaching solution, and the concentration of hydrogen peroxide is 25-35%; and / or the concentration of the sodium hydroxide solution is 30-50%.

[0012] Furthermore, during the purification process, the purification temperature is 80-90° C., the stirring speed is 60-120 rpm, and after stirring for 0.5-1.0 h, the stirring is stopped and allowed to stand for 1.0-2.0 h.

[0013] Furthermore, in the zinc extraction treatment, the treatment temperature is 20-35°C, the stirring speed is 30-60rpm, and the stirring treatment is performed for 0.5-1.0h and then allowed to stand for 1.0-2.0h.

[0014] Further, the energy substrate includes at least one of sulfur, waste sulfur, or waste sulfur paste and at least one of pyrite, waste pyrite, waste sulfide ore, sulfur-containing iron waste rock or sulfur-containing iron tailings; and / or the chelating agent includes at least one of acetic acid, citric acid, oxalic acid or EDTA; and / or the solubilizing agent includes ethylene glycol.

[0015] Furthermore, it also includes: (7) adding the zinc ferrite leaching residue into an organic-inorganic mixed acid solution for purification, and obtaining purified leaching residue after solid-liquid separation; (8) The purified leaching residue is subjected to roasting and modification treatment to obtain zinc ferrite product.

[0016] Further, the organic-inorganic mixed acid solution includes an organic acid and an inorganic acid; wherein the organic acid includes at least one of citric acid, oxalic acid or acetic acid, and the inorganic acid includes dilute sulfuric acid; and / or, in the purification treatment, the solid-liquid ratio is 25~35%, the treatment temperature is 25~40°C, the stirring speed is 20~40rpm, and the washing time is 0.5~1.0h; and / or, in the roasting modification treatment, the roasting temperature is 500~800°C, and the roasting time is 1~2h. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Description of the substance content in the present invention: Solid n%, the ratio of solid mass added to liquid to liquid volume is n%, for example, 2% of waste sulfur means 2g of waste sulfur is added to 100ml of liquid, the unit is g / ml; Liquid n%, the ratio of the added liquid volume to the total liquid volume is n%, for example, the inoculation amount of the strain is 5%, that is, 5ml of the strain is added to 95ml of the culture medium, the total volume is 100ml, and the volume ratio is 5%.

[0019] The present invention provides a method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selectively extracting zinc through bioleaching, comprising the following steps: (1) adding energy substrate to the membrane bioreactor, inoculating at least one of sulfur oxidizing bacteria, iron oxidizing bacteria, or a composite bacterial group of sulfur oxidizing bacteria and iron oxidizing bacteria for cultivation, and obtaining active biological leachate through membrane extraction; (2) adding recycled steel electric furnace ash and at least one of a chelating agent or a solubilizing agent to the active biological leachate, and performing a first leaching treatment in sequence, and obtaining a zinc-containing leaching solution and zinc ferrite leaching residue after solid-liquid separation; (3) returning the zinc-containing leachate to the membrane bioreactor for regeneration until the pH value of the system is between 0.8 and 1.0 to obtain regenerated leachate; (4) adding regenerated steel electric furnace ash to the regenerated leachate for cyclic leaching treatment, and obtaining zinc-rich leaching solution and zinc ferrite leaching slag after solid-liquid separation; (5) adding hydrogen peroxide and sodium hydroxide solution to the zinc-rich leaching solution until the pH value of the system is 5.0-6.0, performing purification treatment, and obtaining a zinc-rich purified solution after solid-liquid separation; (6) Sodium carbonate is added to the zinc-rich purified liquid until the pH value of the system is 8.0-8.5, and zinc extraction is performed to obtain a zinc carbonate product after solid-liquid separation.

[0020] It can be understood that bioleaching refers to the process in which microorganisms dissolve the target metals in solid materials and release them into the liquid phase through the acidolysis, oxidation, reduction and complexation of themselves and their metabolites. It has the characteristics of simple equipment, easy operation, economical and efficient, and environmentally friendly. It is particularly suitable for the removal and detoxification of low-content toxic metals and the leaching and recovery of low-content valuable metals.

[0021] In a specific embodiment, the components of the recycled steel electric furnace ash in the present invention include 20-40% iron, 20-30% zinc, 5-15% sodium, and 1-5% calcium.

[0022] The method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching provided by the present invention utilizes active bioleach continuously prepared by a membrane bioreactor and adds a chelating agent or solubilizing agent of a certain concentration, and by controlling the pH value range in the step system, can effectively selectively leach soluble zinc in the recycled steel electric furnace ash and inhibit the formation of precipitates such as calcium sulfate, magnesium sulfate and lead sulfate in the leached residue; zinc carbonate products can be prepared by removing impurities and precipitating the zinc-rich leachate, thereby realizing the resource utilization of the recycled steel electric furnace ash.

[0023] Specifically, the pH value of the active biological leachate is 0.5~1.0, Fe 2+ The concentration is 0.25~0.5g / L, Fe 3+ The concentration is 0.5~1.0g / L, the organic acid concentration is 150~300mg / L, and the extracellular polymer concentration is 250~500mg / L.

[0024] By further limiting the physical and chemical parameters of the active biological leachate, the soluble zinc in the recycled steel electric furnace ash can be better selectively leached and the formation of precipitates such as calcium sulfate, magnesium sulfate and lead sulfate in the leached slag can be inhibited.

[0025] Furthermore, in the first extraction process and / or the cyclic extraction process, the solid-liquid ratio is 10-20%, the extraction temperature is 25-40° C., the stirring speed is 20-60 rpm, and the extraction time is 1.5-4.0 h.

[0026] The solid-liquid ratio refers to the ratio of the mass of electric furnace ash to the volume of active biological leachate. For example, a 3% solid-liquid ratio means 3 grams of solid is placed in 100 ml of liquid.

[0027] Optionally, the cyclic leaching process can be repeated 3 to 4 times, and the bacteria need to be re-cultured to obtain new active biological leachate to further improve the leaching effect.

[0028] In one specific embodiment, the hydraulic retention time of the regeneration treatment is 24 to 96 hours.

[0029] In a specific embodiment, the amount of hydrogen peroxide added is 0.1-0.2% (v / v) of the zinc-rich leaching solution, and the concentration of hydrogen peroxide is 25-35%; The concentration of sodium hydroxide solution is 30~50%.

[0030] In a specific embodiment, during the purification process, the purification temperature is 80-90° C., the stirring speed is 60-120 rpm, and after stirring for 0.5-1.0 h, the stirring is stopped and allowed to stand for 1.0-2.0 h.

[0031] Furthermore, in the zinc extraction treatment, the treatment temperature is 20-35°C, the stirring speed is 30-60rpm, and the stirring treatment is performed for 0.5-1.0h and then allowed to stand for 1.0-2.0h.

[0032] Optionally, after the zinc extraction process is completed and the solid-liquid separation is completed, the product needs to be washed with distilled water, refined and then dried (temperature 105°C, 1~2h) to obtain a zinc carbonate product.

[0033] Further, the energy substrate includes at least one of sulfur, waste sulfur, or waste sulfur paste and at least one of pyrite, waste pyrite, waste sulfide ore, sulfur-containing iron waste rock, or sulfur-containing iron tailings; The complexing agent includes at least one of acetic acid, citric acid, oxalic acid or EDTA, and the complexing agent; the solubilizing agent includes ethylene glycol.

[0034] Among them, the total concentration of the complexing agent and the solubilizing agent is 0.5~2.0%.

[0035] Furthermore, it also includes: (7) adding the zinc ferrite leaching residue into an organic-inorganic mixed acid solution for purification, and obtaining purified leaching residue after solid-liquid separation; (8) The purified leaching residue is subjected to roasting and modification treatment to obtain zinc ferrite product.

[0036] In a specific embodiment, the organic-inorganic mixed acid solution includes an organic acid and an inorganic acid; wherein the organic acid includes at least one of citric acid, oxalic acid or acetic acid, and the inorganic acid includes dilute sulfuric acid. wherein the amount of the organic acid added is 0.1-0.2%, and the amount of the inorganic acid added is 0.1-0.2%; the organic-inorganic mixed acid solution can be reused after appropriate acid supplementation.

[0037] In the purification treatment, the solid-liquid ratio is 25~35%, the treatment temperature is 25~40°C, the stirring speed is 20~40rpm, and the washing time is 0.5~1.0h; in the roasting modification treatment, the roasting temperature is 500~800°C, and the roasting time is 1~2h.

[0038] The purity (zinc content) of the zinc carbonate product prepared by the invention is ≥56.5%, the moisture content is ≤5.0% (w / w), and the content of the zinc ferrite product is ≥99% (w / w).

[0039] Hereinafter, a method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching provided by the present invention is described in detail through specific examples. Example 1

[0040] Using waste sulfur and waste pyrite (12.0 g / L + 12.0 g / L) as energy substrates and a mixed bacterial community consisting of sulfur oxidizing bacteria and iron oxidizing bacteria as the working bacterial community, active biological leachate was prepared in a continuous manner in a membrane bioreactor (MBR). The pH of the active biological leachate was 0.6, and the Fe 2+ Concentration 0.5g / L, Fe 3+ The concentration is 0.5g / L, the organic acid concentration is 250mg / L, and the extracellular polymer concentration is 350mg / L. The recycled steel electric furnace ash with a zinc content of 13.2% is put into the active biological leachate, and the complexing agent / solubilizer acetic acid (concentration 1.5%) is added. The solid-liquid ratio is 15%, the temperature is 30℃, and the stirring speed is 60 rpm. The leaching is carried out for 1.5h. After the leaching is completed, the mud-water mixture is filtered to separate the mud and water, and the zinc-containing leaching solution and the leaching residue of residual zinc ferrite are collected separately.

[0041] The zinc-containing leachate is refluxed into the MBR, and the hydraulic retention time is controlled at 36h. The regenerated leachate is collected and added to the electric furnace ash for the second and third times. The zinc-rich leachate (zinc enrichment concentration is 39.6g / L, iron enrichment concentration is 2.7g / L) is collected and hydrogen peroxide (0.2%, v / v) and sodium hydroxide solution are added to pH 5.0. At a temperature of 85℃ and a stirring speed of 100 rpm, the reaction is stopped after 0.5h and the stirring is stopped for 1.0h. The lower precipitate is collected and filtered to complete the solid-liquid separation. The zinc-rich purified liquid (zinc concentration is 37.6g / L, iron concentration is 90mg / L) is collected and sodium carbonate is added to pH 8.5. The temperature is 30℃, the stirring speed is 50 rpm, and the reaction is stopped after 1.0h. The lower precipitate was collected and filtered for solid-liquid separation. The solid material was washed twice with distilled water, refined and then dried (105°C, 2h) to obtain a zinc carbonate product with a zinc content of 56.8% and a moisture content of 2.0% (w / w).

[0042] Collect the leaching residue containing residual zinc ferrite, add an organic-inorganic mixed acid solution of 0.1% dilute sulfuric acid and 0.1% citric acid, with a solid-liquid ratio of 35%, a temperature of 30°C, and a stirring speed of 30 rpm. After washing for 1.0h, filter and separate the solid and liquid, and wash twice with distilled water. The mixed acid solution is reused after appropriate acid supplementation. The zinc ferrite purified by deep washing is roasted at 800°C for 2h to modify the structure, crystal form and performance. The spinel zinc ferrite product is harvested, and the zinc ferrite content is ≥99% (w / w). Example 2

[0043] Using sulfur and pyrite (10.0 g / L + 10.0 g / L) as energy substrates and a mixed bacterial community consisting of sulfur oxidizing bacteria and iron oxidizing bacteria as the working bacterial community, active biological leachate was prepared in a continuous manner in a membrane bioreactor (MBR). The pH of the active biological leachate was 0.5, and Fe 2+ Concentration 0.5g / L, Fe 3+ The concentration is 0.5g / L, the organic acid concentration is 250mg / L, and the extracellular polymer concentration is 350mg / L. The recycled steel electric furnace ash with a zinc content of 20% is put into the active biological leachate, and the complexing agent / solubilizer acetic acid (concentration 1.5%) is added. The solid-liquid ratio is 10%, the temperature is 30℃, and the stirring speed is 60 rpm. The leaching is carried out for 1.5h. After the leaching is completed, the mud-water mixture is filtered to separate the mud and water, and the zinc-containing leaching solution and the leaching residue of residual zinc ferrite are collected separately.

[0044] The zinc-containing leachate is refluxed into the MBR, and the hydraulic retention time is controlled at 48h. The regenerated leachate is collected and added to the electric furnace ash for the second and third times. The zinc-rich leachate (zinc enrichment concentration is 35.6g / L, iron enrichment concentration is 2.5g / L) is collected and hydrogen peroxide (0.2%, v / v) and sodium hydroxide solution are added to pH 5.0. At a temperature of 85℃ and a stirring speed of 100 rpm, the reaction is stopped after 0.5h and the stirring is stopped for 1.0h. The lower layer of precipitate is collected and filtered to complete solid-liquid separation. The zinc-rich purified liquid (zinc concentration is 34.6g / L, iron concentration is 85mg / L) is collected and sodium carbonate is added to pH 8.5. The temperature is 30℃, the stirring speed is 50 rpm, and the reaction is stopped after 1.0h. The lower precipitate was collected and filtered for solid-liquid separation. The solid material was washed twice with distilled water, refined and then dried (105°C, 2h) to obtain a zinc carbonate product with a zinc content of 56.5% and a moisture content of 1.5% (w / w).

[0045] Collect the leaching residue containing residual zinc ferrite, add 0.1% dilute sulfuric acid and 0.1% EDTA organic-inorganic mixed acid solution, solid-liquid ratio 30%, temperature 30℃, stirring speed 30 rpm, wash for 1.0h, filter for solid-liquid separation and wash with distilled water 3 times. The mixed acid solution is reused after appropriate acid supplementation, and the zinc ferrite purified by deep washing is roasted at 800℃ for 1.5h to modify the structure, crystal form and performance. The spinel zinc ferrite product is harvested, and the zinc ferrite content is ≥99.5% (w / w). Example 3

[0046] Using sulfur and pyrite (10.0 g / L + 10.0 g / L) as energy substrates and a mixed bacterial community consisting of sulfur oxidizing bacteria and iron oxidizing bacteria as the working bacterial community, active biological leachate was prepared in a continuous manner in a membrane bioreactor (MBR). The pH of the active biological leachate was 0.5, and Fe 2+ Concentration 0.5g / L, Fe 3+ The concentration is 0.5g / L, the organic acid concentration is 250mg / L, and the extracellular polymer concentration is 350mg / L. The recycled steel electric furnace ash with a zinc content of 15% is put into the active biological leachate, and the complexing agent / solubilizer acetic acid (concentration 1.5%) is added. The leaching is carried out for 1.5h at a solid-liquid ratio of 15%, a temperature of 30℃, and a stirring speed of 60 rpm. After the leaching is completed, the mud-water mixture is filtered to separate the mud and water, and the zinc-containing leaching solution and the leaching residue of residual zinc ferrite are collected separately.

[0047] The zinc-containing leachate is returned to the MBR, and the hydraulic retention time is controlled at 36h. The regenerated leachate is collected and put into the electric furnace ash for 2 cycles of leaching. The zinc-rich leachate (zinc enrichment concentration 45.6g / L, iron enrichment concentration 2.7g / L) is collected and hydrogen peroxide (0.2%, v / v) and sodium hydroxide solution are added to pH 5.0. At a temperature of 85℃ and a stirring speed of 100rpm, the reaction is stopped after 0.5h and the stirring is stopped for 1.0h. The lower precipitate is collected and filtered to complete the solid-liquid separation. The zinc-rich purified liquid (zinc concentration 44.2g / L, iron concentration 90mg / L) is collected and sodium carbonate is added to pH 8.5. The temperature is 30℃, the stirring speed is 50rpm, and the reaction is stopped after 1.0h and then the reaction is stopped for 1.0h. The lower precipitate was collected and filtered for solid-liquid separation. The solid material was washed twice with distilled water, refined and then dried (105°C, 2h) to obtain a zinc carbonate product with a zinc content of 56.6% and a moisture content of 1.5% (w / w).

[0048] Collect the leaching residue containing residual zinc ferrite, add 0.1% dilute sulfuric acid and 0.1% EDTA organic-inorganic mixed acid solution, solid-liquid ratio 35%, temperature 30℃, stirring speed 30rpm, wash for 1.0h, filter for solid-liquid separation and wash with distilled water 3 times. The mixed acid solution is reused after appropriate acid supplementation, and the zinc ferrite purified by deep washing is roasted at 800℃ for 2.0h to modify the structure, crystal form and performance. Harvest spinel zinc ferrite products with a zinc ferrite content of ≥99.0% (w / w).

[0049] The method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction through bioleaching provided by the present invention breaks through the traditional pyrometallurgical process of forcibly volatilizing zinc elements in solid waste under high energy input conditions, especially forcibly destroying high-energy bonds in zinc ferrite to promote the separation of zinc and iron elements and high-temperature volatilization of zinc, and utilizes bioleaching technology to obtain selective leaching of soluble zinc in electric furnace ash. On this basis, the green preparation of two types of high-value products, zinc carbonate and zinc ferrite, is completed, and the high-value product utilization of high-zinc hazardous waste electric furnace ash is realized.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein by equivalents. If these modifications and variations fall within the scope of the claims of the present invention and their equivalent technologies, they should be considered to be within the protection scope of the present invention.

Claims

1. A method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching, characterized in that: The following steps are involved: (1) adding energy substrate to the membrane bioreactor, inoculating at least one of sulfur oxidizing bacteria, iron oxidizing bacteria, or a composite bacterial group of sulfur oxidizing bacteria and iron oxidizing bacteria for cultivation, and obtaining active biological leachate through membrane extraction; (2) adding recycled steel electric furnace ash and at least one of a chelating agent or a solubilizing agent to the active biological leachate, and performing a first leaching treatment in sequence, and obtaining a zinc-containing leaching solution and zinc ferrite leaching residue after solid-liquid separation; (3) returning the zinc-containing leachate to the membrane bioreactor for regeneration until the pH value of the system is between 0.8 and 1.0 to obtain regenerated leachate; (4) adding regenerated steel electric furnace ash to the regenerated leachate for cyclic leaching treatment, and obtaining zinc-rich leaching solution and zinc ferrite leaching slag after solid-liquid separation; (5) adding hydrogen peroxide and sodium hydroxide solution to the zinc-rich leaching solution until the pH value of the system is 5.0-6.0, performing purification treatment, and obtaining a zinc-rich purified solution after solid-liquid separation; (6) Sodium carbonate is added to the zinc-rich purified liquid until the pH value of the system is 8.0-8.5, and zinc extraction is performed to obtain a zinc carbonate product after solid-liquid separation.

2. The method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching according to claim 1, characterized in that: The pH value of active biological leachate is 0.5~1.0, Fe 2+ The concentration is 0.25~0.5g / L, Fe 3+ The concentration is 0.5~1.0 g / L, the organic acid concentration is 150~300 mg / L, and the extracellular polymer concentration is 250-500 mg / L.

3. The method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching according to claim 1, characterized in that: In the first extraction process and / or the circulating extraction process, the solid-liquid ratio is 10-20%, the extraction temperature is 25-40°C, the stirring speed is 20-60rpm, and the extraction time is 1.5-4.0h.

4. The method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching according to claim 1, characterized in that: The hydraulic retention time of regeneration treatment is 24~96h.

5. The method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching according to claim 1, characterized in that: The amount of hydrogen peroxide added is 0.1-0.2% by volume of the zinc-rich leaching solution, and the concentration of hydrogen peroxide is 25-35%; and / or, The concentration of sodium hydroxide solution is 30~50%.

6. The method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching according to claim 1, characterized in that: During the purification process, the purification temperature is 80~90°C, the stirring speed is 60~120rpm, and after stirring for 0.5~1.0h, the stirring is stopped and allowed to stand for 1.0~2.0h.

7. The method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching according to claim 1, characterized in that: During the zinc extraction treatment, the treatment temperature is 20~35℃, the stirring speed is 30~60rpm, and the stirring treatment is 0.5~1.0h and then allowed to stand for 1.0~2.0h.

8. The method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching according to claim 1, characterized in that: The energy substrate includes at least one of sulfur, waste sulfur, or waste sulfur paste and at least one of pyrite, waste pyrite, waste sulfide ore, sulfur-containing iron waste rock, or sulfur-containing iron tailings; and / or, The complexing agent includes at least one of acetic acid, citric acid, oxalic acid or EDTA; and / or, Solubilizing agents include ethylene glycol.

9. The method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching according to any one of claims 1 to 8, characterized in that: Also includes: (7) adding the zinc ferrite leaching residue into an organic-inorganic mixed acid solution for purification, and obtaining purified leaching residue after solid-liquid separation; (8) The purified leaching residue is subjected to roasting and modification treatment to obtain zinc ferrite product.

10. The method for preparing zinc carbonate and zinc ferrite from recycled steel electric furnace ash by selective zinc extraction based on bioleaching according to claim 9, characterized in that: The organic-inorganic mixed acid solution comprises an organic acid and an inorganic acid; wherein the organic acid comprises at least one of citric acid, oxalic acid or acetic acid, and the inorganic acid comprises dilute sulfuric acid; and / or, During the purification treatment, the solid-liquid ratio is 25-35%, the treatment temperature is 25-40°C, the stirring speed is 20-40 rpm, and the washing time is 0.5-1.0 h; and / or, In the calcination modification treatment, the calcination temperature is 500~800℃ and the calcination time is 1~2h.