CN110844932A - Method for producing nano zinc oxide by recovering zinc in zinc-containing solid waste of steel plant - Google Patents
Method for producing nano zinc oxide by recovering zinc in zinc-containing solid waste of steel plant Download PDFInfo
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Abstract
The invention discloses a method for producing nano-zinc oxide by recovering zinc in zinc-containing solid waste of a steel plant, belonging to the technical field of chemical metallurgy. The method comprises the steps of selectively treating zinc-containing solid waste in a steel plant, recovering zinc in the zinc-containing solid waste, and producing high-grade nano zinc oxide; meanwhile, after leaching residues are washed to remove the leaching agent carried in the leaching residues, the leaching residues are returned to an iron-making system for recycling of iron elements, double economic benefits are generated, and the environmental protection problem caused by the stockpiling of zinc-containing solid wastes troubling iron and steel enterprises is solved.
Description
Technical Field
The invention belongs to the technical field of chemical metallurgy, and particularly relates to a production system for producing nano zinc oxide by recovering zinc from a zinc-containing material.
Background
In actual production, various processes of iron and steel enterprises can generate solid wastes with different zinc contents, including blast furnace ash, converter ash, electric furnace ash, sintering machine head (tail) ash and the like, wherein the solid wastes generally contain 1-25% of zinc, and the solid wastes contain valuable elements such as iron, zinc, carbon and the like, and for a long time, most of the zinc-containing solid wastes generated by the iron and steel enterprises are directly returned to sintering, then enter the blast furnace to recycle iron elements in the zinc-containing solid wastes, and part of the zinc-containing solid wastes are stockpiled in a factory or sold outside the factory. However, zinc as a valuable element is returned to the blast furnace and can be circularly enriched, so that the damage of a blast furnace lining, accretion in the furnace, corrosion of a gas pipeline and the like are caused, and the smooth production and the service life of the blast furnace are seriously influenced. Therefore, how to reasonably recover the zinc-containing solid waste generated by the steel enterprises and produce zinc-containing products with higher economical efficiency needs deep technical development.
In recent years, the technology of producing nano or high-purity zinc oxide by extracting zinc by an ammonia process is applied to resource treatment of zinc-containing solid waste of steel enterprises because the technology selectively leaches zinc, and patent No. CN102849782A (B) is a method for producing high-purity zinc oxide by decarbonization of steel plant smoke dust by an ammonia process. However, this method has disadvantages: (1) when zinc recovery is carried out on the zinc-containing solid waste with the zinc content of less than 5%, repeated and cyclic leaching is needed for many times due to low zinc content, the economic benefit is low, and enterprises cannot make full use of the method; (2) the ammonia distillation process has large steam consumption, serious equipment corrosion and potential safety hazards of high temperature and high pressure.
Moreover, the zinc-containing solid waste of the steel plant has high salt content, wherein the salt mainly exists in the form of KCL, NaCl and ZnCl, and if the ammonia process leaching is directly carried out, inorganic salts such as KCL, NaCl and the like can enter a system, so that the grade of a zinc oxide product is difficult to ensure, the economic benefit is poor, and the chloride salts can corrode equipment, and the system fails. Therefore, after partial removal of salt in zinc-containing solid waste in steel plants, ammonia leaching is carried out to produce high-grade zinc oxide products.
Disclosure of Invention
In view of the above, the present invention aims to provide a method for producing nano zinc oxide by recovering zinc from zinc-containing solid waste of steel plants, which is used for solving the problems that the recovery of zinc from zinc-containing solid waste of steel enterprises is not thorough, and valuable elements such as iron and carbon in residues cannot be recycled, and also for solving the environmental protection problem caused by the stockpiling of zinc-containing solid waste puzzling the steel enterprises.
The invention is realized by the following technical scheme:
the invention provides a method for producing nano-zinc oxide by recovering zinc in zinc-containing solid waste of a steel plant.
Preferably, the collected solid waste with high zinc content is: solid waste containing zinc with the zinc content of more than 5 percent is produced in each working procedure in the steel plant production.
Preferably, the desalting treatment is:
mixing the high-zinc-content solid waste with water according to the mass ratio of 3: 1-5: 1, adjusting the pH of the mixed solution to 8-10, carrying out wet grinding, and carrying out solid-liquid separation to obtain a first solid and a first filtrate;
and (3) circularly using the first filtrate in the desalting treatment process, and evaporating and crystallizing the first filtrate to obtain mixed salt and condensed water after the total salt content is accumulated to be more than 10%.
Preferably, the ammonia process leach is:
mixing the first solid with an extracting agent, then carrying out wet grinding, and carrying out solid-liquid separation to obtain extracted slag and a second filtrate; the leaching agent is a mixed solution of ammonia and ammonium bicarbonate, the molar concentration of the ammonia is 3-10 mol/L, and the molar concentration of the ammonium bicarbonate is 1-4 mol/L;
the second filtrate is recycled in the ammonia process leaching procedure, and is purified after the content of zinc oxide in the second filtrate is accumulated to be more than 20 g/L.
Preferably, the leaching residue is mixed with water, stirred and washed, and solid-liquid separation is carried out to obtain washed leaching residue and fourth filtrate; the washed leached slag is returned to an iron-making system; the fourth filtrate is recycled as a leaching agent for use in the ammonia process leaching.
Preferably, the purification treatment is: and adopting an optional purification mode to ensure that the total concentration of heavy metal ions except zinc in the purified second filtrate is less than 10 mg/L.
Preferably, the carbonized crystal is: introducing carbon dioxide gas into the purified second filtrate for carbonization and crystallization, and performing solid-liquid separation to obtain a second solid and a fifth filtrate; and the pH value of the crystallization residual liquid at the carbonization crystallization end point reaches: and 6.5-8.0, stopping introducing the carbon dioxide gas.
Preferably, adding quicklime or lime milk into the fifth filtrate for calcification treatment, and performing solid-liquid separation to obtain calcium carbonate and calcification residual liquid; the calcified raffinate is used as lixiviant circularly in the ammonia leaching process.
Preferably, the rinsing treatment is: mixing, stirring and rinsing the second solid by using condensed water obtained by evaporation and crystallization in the desalting treatment, and carrying out solid-liquid separation to obtain a rinsed second solid and a rinsed third filtrate; the third filtrate is recycled to the desalting treatment step.
Preferably, the dry calcination is: and drying and calcining the rinsed second solid at the temperature of 200-440 ℃ to obtain the nano zinc oxide with the grade of not less than 95%.
The invention has the advantages that:
1. the method of the invention carries out selective treatment on the zinc-containing solid waste in the steel plant, namely, the zinc-containing solid waste with the zinc content higher than 5 percent is used as a raw material, the zinc in the zinc-containing solid waste is recycled, and the high-grade nano zinc oxide is produced; meanwhile, after leaching residues are washed to remove the leaching agent carried in the leaching residues, the leaching residues are returned to an iron-making system to recycle iron elements and the like, so that double economic benefits are generated, and the environmental protection problem caused by the stockpiling of zinc-containing solid wastes which troubles iron and steel enterprises is solved.
2. The method carries out desalination treatment on the high-zinc-content solid waste, and not only recovers the mixed salt in the high-zinc-content solid waste; the smooth operation of the zinc leaching and recovering system by the ammonia process is also ensured, and the corrosion of equipment is reduced.
3. In the method, the first filtrate is evaporated and crystallized to obtain condensed water which is used as a second solid generated in the rinsing, carbonization and crystallization process, the fourth filtrate generated by washing leaching residues and the calcification residual liquid generated by calcification treatment of the fifth filtrate are used in the ammonia method leaching process for recycling, and the third filtrate generated by rinsing the second solid is used in the desalination treatment process for recycling, so that water resources are recycled, and zero emission of wastewater is realized.
4. According to the method, the reaction efficiency of the carbonization crystallization is fully analyzed, the adopted carbon dioxide gas is introduced into the second filtrate in two stages, the flow rate and molar weight relation between the carbon dioxide gas and the second filtrate is utilized, the carbonization crystallization effect is improved, and the loss of the carbon dioxide is reduced; meanwhile, the aeration device is adopted to distribute carbon dioxide gas in a distributed manner, so that the carbonized crystal granularity meets the production requirement of the nano-zinc oxide.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.
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In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings, in which:
FIG. 1 is a schematic flow diagram of 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 application range of the method disclosed by the invention is not particularly limited, and the method can be widely applied to the utilization of zinc-containing solid wastes generated in various processes of steel plants. The zinc-containing solid waste comprises but is not limited to blast furnace ash, converter ash, electric furnace ash, head (tail) ash of a sintering machine and the like, and is selectively collected according to the zinc content, particularly the zinc-containing solid waste with the zinc content of more than 5 percent, and zinc recovery is carried out on zinc in the zinc-containing material by combining with an ammonia leaching process, so that the zinc in the zinc-containing material is recovered to the maximum extent; in particular, the intermediate zinc oxide precursor of the present disclosure is basic zinc carbonate [ Zn ]2(OH)2CO3]Zinc hydroxide [ Zn (OH) ]2]And zinc carbonate (ZnCO)3]Or a combination thereof; in particular, heavy metal ions of the present disclosure include, but are not limited to, iron, cadmium, manganese, lead, chromium, mercury, arsenic, and the like; in particular, "optional" of the present disclosure means that the subsequently described step may or may not be performed, or is otherwise substituted, and that the expression includes instances where the subsequently described step is performed, instances where the subsequently described step is not performed, and instances where the subsequently described step is otherwise substituted.
As shown in fig. 1, in the present embodiment, a method for producing nano zinc oxide by recovering zinc from zinc-containing solid waste of a steel mill includes sequentially performing desalination, ammonia leaching, purification, carbonization crystallization, rinsing, drying and calcination on collected high zinc-containing solid waste to obtain nano zinc oxide, wherein:
s1, desalting treatment: the salt in the zinc-containing solid waste (various zinc-containing ash, dust and slag) of a steel plant mainly exists in the forms of KCl and NaCl, and is dissolved in water through water washing of the zinc-containing solid waste, and the salt in the zinc-containing solid waste is carried away through water, so that the aim of desalting is fulfilled. Specifically, the high zinc-containing solid waste is mixed with water, wet grinding is carried out (grinding time is not limited, selection is carried out according to the desalting effect of each batch of dedusting ash and the actual requirement is combined, preferably 30min), then solid-liquid separation is carried out by a plate and frame filter press to obtain a first solid (namely the desalted high zinc-containing solid waste) and a first filtrate (namely salt-containing water), the first filtrate is recycled for desalting treatment, and when the total salt in the first filtrate is desaltedAfter the component is accumulated to be more than 10 percent, the mixed salt is obtained by carrying out evaporative crystallization (including multi-effect evaporation or Mechanical Vapor Recompression (MVR) technology) evaporation). The condensed water obtained by evaporation and crystallization is used as the rinsing water of the zinc oxide precursor. In the process, (1) the pH value of the mixed liquid of the high-zinc-content solid waste and water is adjusted to 8-10, so that zinc dissolved in the water in the desalting process is precipitated in the first solid in the form of zinc hydroxide and is not taken away by the first filtrate (salt-containing water). Namely, in the desalting process, the zinc-containing solid waste contains ZnCl2，ZnCl2Can be dissolved in water in the water washing process and is taken away by desalted water, thus causing the loss of zinc. Therefore, in the desalting process, the pH of the solution is controlled to 9 to make Zn in the water2+With Zn (OH)2Is precipitated in the desalted first solid. (2) The mass ratio of the high zinc-containing solid waste of the steel plant to the water is 4: 1. (3) The high zinc-containing solid waste of the steel plant is zinc-containing solid waste with the zinc content of more than 5 percent. (4) The desalting reactor is adopted to carry out desalting treatment on the high-zinc-content solid waste, so that mixed salt in the high-zinc-content solid waste is recycled, the smooth operation of leaching and recycling by an ammonia process is ensured, and the corrosion of equipment is reduced.
S2, leaching by an ammonia method: mixing the first solid obtained in the desalting treatment step with a leaching agent (namely a mixed solution of ammonia and ammonium bicarbonate, wherein the molar concentration of the ammonia is 5mol/L, and the molar concentration of the ammonium bicarbonate is 2mol/L), pulping, performing wet grinding (the grinding time is not limited, and the selection is performed according to the actual requirement according to the new leaching effect in each batch of dust removal ash, preferably 2 hours), performing solid-liquid separation by using a plate and frame filter press to obtain leaching residue (namely high-zinc-content solid waste residue after zinc recovery) and second filtrate (namely zinc ammonia complex liquid), recycling the second filtrate for ammonia leaching, and entering the next purification treatment process after the zinc oxide content in the second filtrate is accumulated to be more than 20 g/L. Mixing the leaching residue with water, stirring (stirring time is not limited, and selecting according to actual needs, preferably 30min), washing to remove leaching agent carried therein, performing solid-liquid separation with plate-and-frame filter press to obtain fourth filtrate, recovering leaching agent, returning to ammonia leaching process, and circulating as leaching agentAnd (4) utilizing. And the washed leached slag enters an iron-making system to be used as an iron-making raw material. In the process, an ammonia process leaching reactor is adopted to carry out ammonia process leaching on the high-zinc-content solid waste to produce zinc-ammonia complex liquid, and zinc in the high-zinc-content solid waste mainly comprises ZnO and ZnSiO3The ammonia process leaching process mainly comprises the following chemical reactions:
ZnO+(n-1)NH3+NH4HCO3＝[Zn(NH3)n]CO3+H2O
ZnSiO3+nNH3+2NH4HCO3→[Zn(NH3)n]CO3+SiO2·H2O+(NH4)2CO3
Zn(OH)2+(n-1)NH3+NH4HCO3→[Zn(NH3)n]CO3+H2O
wherein n is 1 to 4, ZnO, ZnSiO3、Zn(OH)2By the above reaction, most of the copper, cadmium, mercury, etc. are leached out, and similar chemical reactions occur to enter the solution.
Due to Mn in the ammonia leaching process2+、Mn4+、Pb2+、Pb4+、Fe2+、Fe3+Reaction with water to form Mn (OH)2、Mn(OH)4、Pb(OH)2、Pb(OH)4、Fe(OH)2、Fe(OH)3And (4) precipitating. Therefore, some insoluble compounds are left in the leaching residue in the ammonia leaching process to precipitate out, and the leaching solution (i.e. the second filtrate) is subjected to deep impurity removal through subsequent purification.
S3, purification treatment: adopting an optional purification method, such as sequentially purifying with potassium permanganate and zinc powder, so that the total concentration of heavy metal ions except zinc in the purified second filtrate (namely the zinc-ammonia complex solution) is less than 10 mg/L; the heavy metal ions include, but are not limited to, iron, cadmium, manganese, lead, chromium, mercury, arsenic. In the process, the residual impurities in the zinc-ammonia complex solution comprise Fe2+、 Mn2 +、AsO3-、Pb2+、Cu2+、Cd2+、Ni2+、Hg2+Etc. need to pass throughFurther decontamination protocol removal; the purification reactor is adopted to purify and remove impurities from the zinc-ammonia complex liquid obtained by ammonia extraction, and if solid substances are generated in the zinc-ammonia complex liquid after purification and impurity removal in the process, a plate-and-frame filter press can be used for carrying out solid-liquid separation to obtain purified slag, and the purified slag is returned to an iron-making system to produce a metallized product as an iron-making raw material. The reaction equation for purification is as follows:
3Fe2++MnO4 -+7H2O→MnO2↓+3Fe(OH)3↓+5H+
3AsO3 3-+2MnO4 -+H2O→2MnO2↓+3AsO4 3-+2OH-
AsO4 3-+Fe3-→FeAsO4↓
M2++Zn→M↓+Zn2+
m comprises: pb2+、Cu2+、Cd2+、Ni2+、Hg2+And (3) plasma.
S4, carbonization and crystallization: and introducing carbon dioxide gas into the purified second filtrate for carbonization and crystallization to obtain carbonized crystal slurry, and then performing solid-liquid separation by using a plate-and-frame filter press to obtain a second solid (namely the zinc oxide precursor) and a fifth filtrate (namely the crystallization residual liquid). In the process, (1) a crystallization reactor is adopted to carry out carbonization and crystallization on the purified zinc-ammonia complex liquid, and the crystallization end point is that the pH of the crystallization residual liquid reaches: 6.5-8.0, and stopping introducing carbon dioxide after the crystallization end point is reached. (2) And introducing the carbon dioxide into the purified second filtrate (namely the purified zinc-ammonia complex solution) through an aeration device, wherein the carbon dioxide must have certain pressure when being introduced into the purified second filtrate, and the pressure is ensured to be 2-3 times of the sum of the static pressure of the carbon dioxide at the inlet of the crystallization reactor, the pressure loss of the carbon dioxide through the aeration device in the crystallization reactor and the pressure loss of a pipeline system. (3) Carbon dioxide is introduced in two stages: the first stage is as follows: controlling the flow of carbon dioxide gas to ensure that the ratio of the molar concentration of the carbon dioxide introduced into the solution to the molar concentration of the total ammonia in the zinc-ammonia complex solution is 1.25 until the pH value of the crystallization residual liquid reaches 8.5; and a second stage: after the pH value of the crystallization residual liquid reaches 8.5, controlling the flow of carbon dioxide gas to ensure that the ratio of the molar concentration of the carbon dioxide introduced into the solution to the molar concentration of the total ammonia in the zinc-ammonia complex solution is 2.5, and until the crystallization end point is reached, the pH value of the crystallization residual liquid is as follows: 6.5 to 8.0. Fully analyze the reaction efficiency of carbonization crystallization in this process, the carbon dioxide gas that adopts divide into two stages and lets in the second filtrating, has utilized velocity of flow and molar quantity relation between carbon dioxide gas and the second filtrating, promotes carbonization crystallization effect, has reduced the loss of carbon dioxide. The crystallization reactor for carbonization crystallization is a static pressure closed structure, including but not limited to a reaction kettle, a reaction tank and the like, wherein the gas above the zinc ammine complex liquid is discharged into another treatment process through a pipeline, and an aeration device for uniformly distributing carbon dioxide to participate in the carbonization crystallization reaction is arranged in the zinc ammine complex liquid, and comprises but not limited to a micropore diffuser, a middle bubble diffuser, a big bubble diffuser, a jet diffuser and a fixed spiral diffuser, namely the aeration device distributes the carbon dioxide gas in a distributed manner, so that the granularity of the carbonization crystallization meets the production of nano-scale zinc oxide; the device is provided with a compressor used for pressurizing industrial carbon dioxide to enter a crystallization reactor and an ultrasonic device which acts on the crystallization reactor and is used for assisting the zinc-ammonia complex liquid to carry out carbonization and crystallization.
The main chemical reactions of the crystallization process are:
CO2+2NH3·H2O→(NH4)2CO3+H2O
6Zn(NH3)nCO3+(3n-4)CO2+(6n+8)H2O→2[ZnCO3·2Zn(OH)2·H2O]+3n(NH4)2CO3
and (3) treatment of crystallization residual liquid: after the crystallization reaches the process design end point, the crystallization residual liquid contains a large amount of CO3 2-Simultaneously due to large amount of NH4+The existence of the carbon dioxide leads the pH value to be close to neutral, so that the crystallization raffinate needs to be treated to remove excessive CO in the raffinate3 2-Removing CO from the residue3 2-After the concentration is adjusted to the concentration required by the leaching solution, the leaching solution returns to the leaching process for recycling, and the project design adopts quicklime (CaO) or lime milk to treat the crystallized residual liquid. The main chemical reactions for the treatment of the crystallization residual liquid are as follows:
adding quicklime or lime milk into fifth filtrate (crystallization residual liquid) obtained by carbonization and crystallization, mixing and stirring for calcification treatment, then carrying out solid-liquid separation by using a plate-and-frame filter press to obtain calcification residual liquid and calcium carbonate, and returning the calcification residual liquid to the ammonia process leaching procedure for recycling as a leaching agent. In the process, the amount of the added quicklime or lime milk is 100 to 150 percent of the sum of the molar concentrations of carbonate and carbonate in the fifth filtrate (namely the crystallization residual liquid), and the quicklime or lime milk is utilized for calcification treatment to obtain a byproduct calcium carbonate product, so that the economic benefit is further improved; the calcification residual liquid is recycled, so that water resources can be saved on one hand, and unreacted zinc components in the calcification residual liquid can be further recovered on the other hand.
S5, rinsing treatment comprises the following steps: rinsing the zinc oxide precursor by using a rinsing tank, wherein the rinsing agent is condensed water obtained by evaporation and crystallization in desalination treatment; mixing the second solid (namely the zinc oxide precursor) with condensed water obtained by evaporation and crystallization in desalination treatment, stirring and rinsing, and performing solid-liquid separation by using a plate-and-frame filter press to obtain rinsed second solid and third filtrate; the third filtrate is recycled to the desalting treatment process; the rinsing mode is internal unidirectional circulation, the times are 2-4, namely, the rinsing liquid after the next rinsing is used as the previous rinsing; and the rinsing liquid after rinsing in the rinsing tank enters a desalting treatment process so as to be reused. In this case, three rinses are used, wherein the rinse liquid after the third rinse is used for the second rinse, the rinse liquid after the second rinse is used for the first rinse, and the rinse liquid after the first rinse is introduced into the desalting process for adding water for desalting. Thus, the utilization rate of water resources is improved and the recovery of zinc in the rinsing liquid is facilitated. Of course in different embodiments the rinsing agent may be tap water or pure water. In the process, the zinc oxide precursor can be further desalted and purified, so that the aim of purification is fulfilled.
S6, drying and calcining: and drying and calcining the rinsed second solid to obtain nano zinc oxide with the grade of not less than 95%, and packaging and selling the nano zinc oxide by a zinc oxide packaging machine. Drying at 150-220 ℃, preferably drying at 180-200 ℃, and calcining at 220-440 ℃ for 2h, preferably calcining at 320-370 ℃. The main chemical reactions in this process are:
ZnCO3·2Zn(OH)2·H2O→3ZnO+CO2+2H2O。
by adopting the scheme, the method carries out selective treatment on the zinc-containing solid waste in the steel plant, namely, the zinc-containing solid waste with the zinc content higher than 5 percent is used as a raw material, the zinc in the zinc-containing solid waste is recycled, and the high-grade nano zinc oxide is produced; meanwhile, after leaching residues are washed to remove the leaching agent carried in the leaching residues, the leaching residues are returned to an iron-making system to recycle iron elements and the like, so that double economic benefits are generated, and the environmental protection problem caused by the stockpiling of zinc-containing solid wastes which troubles iron and steel enterprises is solved. The method also obtains condensed water by evaporating and crystallizing the first filtrate to be used as a second solid generated in the rinsing, carbonization and crystallization process, uses a fourth filtrate generated by washing leaching residues and a calcification residual liquid generated by calcification treatment of a fifth filtrate to be recycled in the ammonia method leaching process, and uses a third filtrate generated by rinsing the second solid to be recycled in the desalination treatment process, so that water resources are recycled, and zero emission of wastewater is realized.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and it is apparent that those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (10)
1. A method for producing nano-zinc oxide by recovering zinc in zinc-containing solid waste of a steel plant is characterized in that the collected high-zinc-containing solid waste is sequentially subjected to desalination, ammonia leaching, purification, carbonization and crystallization, rinsing, drying and calcination to obtain the nano-zinc oxide.
2. The method for producing nano zinc oxide by recovering zinc in the zinc-containing solid waste of the steel mill according to claim 1, wherein the collected high zinc-containing solid waste is: solid waste containing zinc with the zinc content of more than 5 percent is produced in each working procedure in the steel plant production.
3. The method for producing nano zinc oxide by recovering zinc in the zinc-containing solid waste of the steel mill according to claim 2, wherein the desalting treatment is as follows:
mixing the high-zinc-content solid waste with water according to the mass ratio of 3: 1-5: 1, adjusting the pH of the mixed solution to 8-10, carrying out wet grinding, and carrying out solid-liquid separation to obtain a first solid and a first filtrate;
and (3) circularly using the first filtrate in the desalting treatment process, and evaporating and crystallizing the first filtrate to obtain mixed salt and condensed water after the total salt content is accumulated to be more than 10%.
4. The method for recovering zinc in the zinc-containing solid waste of the steel mill to produce nano zinc oxide according to claim 3, wherein the ammonia leaching is:
mixing the first solid with an extracting agent, then carrying out wet grinding, and carrying out solid-liquid separation to obtain extracted slag and a second filtrate; the leaching agent is a mixed solution of ammonia and ammonium bicarbonate, the molar concentration of the ammonia is 3-10 mol/L, and the molar concentration of the ammonium bicarbonate is 1-4 mol/L;
the second filtrate is recycled in the ammonia process leaching procedure, and is purified after the content of zinc oxide in the second filtrate is accumulated to be more than 20 g/L.
5. The method for producing nano zinc oxide by recovering zinc in the zinc-containing solid waste of the steel mill according to claim 4, wherein the leaching residues are mixed with water, stirred and washed, and subjected to solid-liquid separation to obtain washed leaching residues and a fourth filtrate; the washed leached slag is returned to an iron-making system; the fourth filtrate is recycled as a leaching agent for use in the ammonia process leaching.
6. The method for producing nano zinc oxide by recovering zinc in the zinc-containing solid waste of the steel mill according to claim 4 or 5, characterized in that the purification treatment is as follows: and adopting an optional purification mode to ensure that the total concentration of heavy metal ions except zinc in the purified second filtrate is less than 10 mg/L.
7. The method for producing nano zinc oxide by recovering zinc in the zinc-containing solid waste of the steel mill according to claim 6, wherein the carbonization crystallization is as follows: introducing carbon dioxide gas into the purified second filtrate for carbonization and crystallization, and performing solid-liquid separation to obtain a second solid and a fifth filtrate; and the pH value of the crystallization residual liquid at the carbonization crystallization end point reaches: and 6.5-8.0, stopping introducing the carbon dioxide gas.
8. The method for producing nano zinc oxide by recovering zinc in the zinc-containing solid waste of the steel mill according to claim 7, wherein quicklime or lime milk is added into the fifth filtrate for calcification treatment, and calcium carbonate and calcification residual liquid are obtained by solid-liquid separation; the calcified raffinate is used as lixiviant circularly in the ammonia leaching process.
9. The method for producing nano zinc oxide by recovering zinc in the zinc-containing solid waste of the steel mill according to claim 7 or 8, characterized in that the rinsing treatment is: mixing, stirring and rinsing the second solid by using condensed water obtained by evaporation and crystallization in the desalting treatment, and carrying out solid-liquid separation to obtain a rinsed second solid and a rinsed third filtrate; the third filtrate is recycled to the desalting treatment step.
10. The method for producing nano zinc oxide by recovering zinc in the zinc-containing solid waste of the steel mill according to claim 9, characterized in that the drying and calcining is: and drying and calcining the rinsed second solid at the temperature of 200-440 ℃ to obtain the nano zinc oxide with the grade of not less than 95%.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112158874A (en) * | 2020-09-19 | 2021-01-01 | 江苏省沙钢钢铁研究院有限公司 | Blast furnace cloth bag ash resource utilization process method |
| CN114150156A (en) * | 2021-11-30 | 2022-03-08 | 西安建筑科技大学 | Process for extracting zinc from low-grade zinc-containing dust and preparing nano zinc oxide |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103896325A (en) * | 2014-04-04 | 2014-07-02 | 黄有余 | Calcined zinc oxide production technology |
| CN105293564A (en) * | 2015-10-05 | 2016-02-03 | 李果 | Method for recycling zinc-containing dust ash in steel plant |
| CN106191453A (en) * | 2016-08-31 | 2016-12-07 | 四川省新源泰环保科技有限责任公司 | A kind of rotary hearth furnace dirt ash is utilized to reclaim zinc enriched substance and the method for potassium chloride |
| CN108328642A (en) * | 2018-02-01 | 2018-07-27 | 昆明理工大学 | A method of non-evaporating hair prepares basic zinc carbonate from zinc ammonia solution |
| CN108793227A (en) * | 2018-07-24 | 2018-11-13 | 重庆东群科技有限公司 | A method of producing nano zine oxide using containing zinc ore crude |
-
2019
- 2019-10-31 CN CN201911063604.XA patent/CN110844932A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103896325A (en) * | 2014-04-04 | 2014-07-02 | 黄有余 | Calcined zinc oxide production technology |
| CN105293564A (en) * | 2015-10-05 | 2016-02-03 | 李果 | Method for recycling zinc-containing dust ash in steel plant |
| CN106191453A (en) * | 2016-08-31 | 2016-12-07 | 四川省新源泰环保科技有限责任公司 | A kind of rotary hearth furnace dirt ash is utilized to reclaim zinc enriched substance and the method for potassium chloride |
| CN108328642A (en) * | 2018-02-01 | 2018-07-27 | 昆明理工大学 | A method of non-evaporating hair prepares basic zinc carbonate from zinc ammonia solution |
| CN108793227A (en) * | 2018-07-24 | 2018-11-13 | 重庆东群科技有限公司 | A method of producing nano zine oxide using containing zinc ore crude |
Non-Patent Citations (1)
| Title |
|---|
| 孙武: "次氧化锌综合回收利用技术研究", 《中国优秀博硕士学位论文全文数据看（硕士） 工程科技Ι辑》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112158874A (en) * | 2020-09-19 | 2021-01-01 | 江苏省沙钢钢铁研究院有限公司 | Blast furnace cloth bag ash resource utilization process method |
| CN114150156A (en) * | 2021-11-30 | 2022-03-08 | 西安建筑科技大学 | Process for extracting zinc from low-grade zinc-containing dust and preparing nano zinc oxide |
| CN114150156B (en) * | 2021-11-30 | 2023-10-13 | 西安建筑科技大学 | Low-grade zinc-containing dust zinc extraction and nano zinc oxide preparation process |
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