CN113929125A - A method for preparing pseudo-boehmite by using fly ash - Google Patents
A method for preparing pseudo-boehmite by using fly ash Download PDFInfo
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- VXAUWWUXCIMFIM-UHFFFAOYSA-M aluminum;oxygen(2-);hydroxide Chemical compound [OH-].[O-2].[Al+3] VXAUWWUXCIMFIM-UHFFFAOYSA-M 0.000 title claims abstract 22
- 239000010881 fly ash Substances 0.000 title claims abstract 12
- 238000000034 method Methods 0.000 title claims abstract 9
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 claims abstract 20
- 238000002386 leaching Methods 0.000 claims abstract 14
- 239000000243 solution Substances 0.000 claims abstract 12
- 239000007788 liquid Substances 0.000 claims abstract 7
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract 6
- 238000000926 separation method Methods 0.000 claims abstract 6
- 239000007864 aqueous solution Substances 0.000 claims abstract 5
- 239000013078 crystal Substances 0.000 claims abstract 5
- 239000002253 acid Substances 0.000 claims abstract 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract 4
- 229910052782 aluminium Inorganic materials 0.000 claims abstract 4
- 238000001027 hydrothermal synthesis Methods 0.000 claims abstract 4
- 239000012535 impurity Substances 0.000 claims abstract 4
- 239000000463 material Substances 0.000 claims abstract 4
- 238000002156 mixing Methods 0.000 claims abstract 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract 4
- 238000001704 evaporation Methods 0.000 claims abstract 3
- 239000007787 solid Substances 0.000 claims abstract 3
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 claims abstract 2
- 229910001424 calcium ion Inorganic materials 0.000 claims abstract 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract 2
- 229910052742 iron Inorganic materials 0.000 claims abstract 2
- -1 iron ions Chemical class 0.000 claims abstract 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims 6
- 238000004519 manufacturing process Methods 0.000 claims 5
- 238000005406 washing Methods 0.000 claims 3
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 claims 2
- 239000003456 ion exchange resin Substances 0.000 claims 2
- 229920003303 ion-exchange polymer Polymers 0.000 claims 2
- 239000000047 product Substances 0.000 claims 2
- 238000001035 drying Methods 0.000 claims 1
- 230000008020 evaporation Effects 0.000 claims 1
- 239000012065 filter cake Substances 0.000 claims 1
- 238000003825 pressing Methods 0.000 claims 1
- 230000035484 reaction time Effects 0.000 claims 1
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical group [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 abstract 1
- 239000002956 ash Substances 0.000 abstract 1
- 238000001354 calcination Methods 0.000 abstract 1
- 238000000605 extraction Methods 0.000 abstract 1
- 150000002500 ions Chemical class 0.000 abstract 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 abstract 1
- 239000004575 stone Substances 0.000 abstract 1
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/48—Halides, with or without other cations besides aluminium
- C01F7/56—Chlorides
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/021—After-treatment of oxides or hydroxides
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/30—Preparation of aluminium oxide or hydroxide by thermal decomposition or by hydrolysis or oxidation of aluminium compounds
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
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- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
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- Inorganic Chemistry (AREA)
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- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
本发明公开了一种利用粉煤灰制备拟薄水铝石的方法，包括如下步骤：1)将粉煤灰进行酸液浸出，得到浸出料；对浸出料固液分离，得到浸出液和粉煤灰提铝残渣；2)将浸出液除杂，去除铁离子和钙离子，得到纯净的氯化铝溶液；3)对纯净的氯化铝溶液进行蒸发结晶，获得氯化铝晶体；4)将氯化铝晶体焙烧，得到活性氧化铝；5)将活性氧化铝与水混合后水热反应，得到拟薄水铝石水溶液；6)对拟薄水铝石水溶液进行固液分离，得到拟薄水铝石产品。本发明利用粉煤灰中铝及杂质离子的存在状态，采用一条新的工艺流程，制备出拟薄水铝石产品。
The invention discloses a method for preparing pseudo-boehmite by using fly ash, which comprises the following steps: 1) leaching the fly ash with acid solution to obtain leaching material; separating the leaching material from solid and liquid to obtain leaching solution and fly ash Ash extraction of aluminum residues; 2) removing impurities from the leaching solution, removing iron ions and calcium ions, to obtain pure aluminum chloride solution; 3) evaporating and crystallizing the pure aluminum chloride solution to obtain aluminum chloride crystals; calcination of aluminum oxide crystal to obtain activated alumina; 5) hydrothermal reaction after mixing activated alumina with water to obtain a pseudo-boehmite aqueous solution; 6) solid-liquid separation of pseudo-boehmite aqueous solution to obtain pseudo-boehmite aqueous solution Aluminum stone products. The invention utilizes the existing state of aluminum and impurity ions in fly ash and adopts a new technological process to prepare pseudo-boehmite products.
Description
Technical Field
The invention relates to a method for preparing pseudo-boehmite, in particular to a method for preparing pseudo-boehmite by utilizing fly ash.
Background
The pseudoboehmite is an important hydrated alumina and an important precursor for preparing various crystal forms of alumina such as gamma-alumina, alpha-alumina and the like. With the increasingly refined requirements of industries such as petrochemical industry and the like on the important catalyst carrier precursor pseudoboehmite, the pseudoboehmite produced by the existing method can not meet the application requirements more and more.
At present, the industrial production method of pseudo-boehmite is mainly divided into a neutralization method and an aluminum alkoxide method according to different raw materials. The method for producing the pseudoboehmite mainly adopts a neutralization method, has cheap raw materials and low production cost, but needs to consume a large amount of acid and alkali, discharges much waste water in the impurity removal process, and is not environment-friendly. The aluminum alkoxide method is a process for producing high-quality pseudo-boehmite by taking high-purity aluminum cyclone chips and higher alcohols (n-amyl alcohol and n-hexyl alcohol) as raw materials, which is developed by Condea company in Germany, and the method has the advantages of good crystal form, easy control of pore structure, large specific surface area and high purity of products; however, the method has high production cost, and the used organic solvent has certain toxicity.
Chinese patent publication No. CN 102849764A discloses a method for preparing pseudo-boehmite by using fly ash, which comprises sieving fly ash, calcining to remove carbon, and mixing with Na2CO3Calcined nepheline phase NaAlSiO4Then acid leaching to generate AlCl3After NaOH is added to obtain sodium metaaluminate solution, the sodium metaaluminate solution is mixed with NaHCO3The solution reacts to form gel, and the pseudoboehmite is prepared after aging and filtration. However, this method has the following problems: 1) the method adopts more raw materials, and the components of the solution are relatively complex, thus being not beneficial to the recycling of the solution; 2) the method adopts two-stage calcination, and has the problems of high energy consumption and the like.
The fly ash is industrial solid waste generated by coal-fired power plants, has huge discharge amount and causes environmental pollution in long-term storage. The resource utilization of the fly ash is more and more emphasized, and in the face of the situation that the existing pseudo-boehmite raw material has high cost and insufficient utilization of the fly ash, the method provides the method for preparing the pseudo-boehmite by taking the fly ash as the raw material and extracting and separating the main components of the fly ash, improves the utilization level of the fly ash, realizes the high-valued utilization of the fly ash, meets the requirement of developing the circular economy in China, and meets the strategic requirements of energy conservation, emission reduction and comprehensive utilization of resources in China.
Disclosure of Invention
The invention provides a method for preparing pseudo-boehmite by using fly ash, which makes up the defects of the prior art, and prepares a pseudo-boehmite product by using the existing states of aluminum and impurity ions in the fly ash and adopting a new process flow.
In order to achieve the purpose, the invention adopts the following technical scheme: a method for preparing pseudo-boehmite by utilizing fly ash comprises the following steps:
1) leaching the fly ash with acid liquor to obtain a leaching material; carrying out solid-liquid separation on the leaching material to obtain a leaching solution and a residue of extracting aluminum from the fly ash;
2) removing impurities from the leaching solution, and removing iron ions and calcium ions to obtain a pure aluminum chloride solution;
3) evaporating and crystallizing the pure aluminum chloride solution to obtain aluminum chloride crystals;
4) roasting the aluminum chloride crystal to obtain activated alumina;
5) mixing activated alumina with water, and carrying out hydrothermal reaction to obtain a pseudo-boehmite aqueous solution;
6) and carrying out solid-liquid separation on the pseudo-boehmite aqueous solution to obtain a pseudo-boehmite product.
According to the method, the acid liquor leaching in the step 1) is used for converting part of alumina in the fly ash into an aluminum salt raw material required by pseudo-boehmite preparation, and the acid liquor leaching can reduce the raw material consumption of the whole process.
In a specific embodiment, in the step 1), the acid solution is preferably hydrochloric acid, and the concentration of the hydrochloric acid is preferably 20-38% by mass, and more preferably 25-35%; the leaching temperature is 110-170 ℃, preferably 120-140 ℃ and the time is 2-8 hours; in addition, the preferable mass ratio of the fly ash to the hydrochloric acid can be controlled to be 1: 2.5-1: 3.5, further preferably 1: 3, the concentration of the aluminum chloride in the leachate obtained by the acid solution leaching can be 200-350g/L, such as 300 g/L.
According to the process of the present invention, the solid-liquid separation in step 1) may be carried out by a conventional separation method, such as plate-and-frame filtration. It can be understood that the separated fly ash aluminum extraction residue can be further utilized and recycled.
In a specific embodiment, the method further comprises the following steps: washing the residue after extracting aluminum from the fly ash, and merging the obtained washing liquid into the leaching solution, thereby further improving the utilization rate of the fly ash.
According to the method, the impurity removal method of the leachate in the step 2) is not limited, and the iron ions and the calcium ions can be removed. For example, the leachate is passed through a cation exchange resin which removes metal impurities.
In a specific embodiment, the leachate can be sequentially subjected to iron ion removal exchange resin and calcium ion removal exchange resin to remove iron ions and calcium ions, wherein the concentration of aluminum chloride can be controlled to be 180-320g/L, the flow rate is 1-5Bv/h, the temperature is 20-80 ℃, preferably 20-40 ℃, and a pure aluminum chloride solution is obtained after impurity removal, wherein the concentration of aluminum chloride is the concentration before impurity removal, the concentration is basically unchanged after impurity removal, and the loss is extremely small.
According to the process of the invention, in the evaporative crystallization of step 3): the evaporation temperature is 60-130 ℃, preferably, the concentration of aluminum chloride starts to crystallize at about 360g/L, and the crystallization process is stopped when the precipitation rate is about 80%.
According to the method of the invention, the calcination temperature of the aluminum chloride crystals in the step 4) is 200-500 ℃, preferably 300-400 ℃, more preferably 350 ℃, and the calcination time is 2-6 hours, so as to obtain the activated alumina. It will be appreciated that the calcination may be carried out using conventional equipment, such as a calciner or calciner, and the aluminium chloride crystals may be exposed to an air atmosphere.
According to the method, in the step 5), the activated alumina is mixed with water and then subjected to hydrothermal reaction so as to convert the activated alumina into a crystal form, wherein the activated alumina is an amorphous phase and is converted into a pseudo-boehmite phase after hydrothermal reaction.
In a specific embodiment, the activated alumina and water can be mixed according to a certain proportion, and the mass ratio is 1: 3-1: 15; the hydrothermal reaction temperature is 100-250 ℃, preferably 150-200 ℃, more preferably 180 ℃, and the hydrothermal reaction time is preferably 2-6 hours, more preferably 3-4 hours. The optimized parameter setting can ensure that the product has better crystallinity and lower impurity content.
According to the method, solid-liquid separation is carried out on the pseudoboehmite in the step 6), and a filter pressing or centrifugal separation mode is preferentially adopted.
In a specific embodiment, the pseudoboehmite can be subjected to solid-liquid separation to obtain a solid, and the solid is washed and dried to obtain a pseudoboehmite product. Such as: washing with pure water for 2 times, and drying the washed filter cake at 80-120 deg.C.
According to the method of the present invention, the fly ash is high alumina fly ash, such as high alumina fly ash discharged from a circulating fluidized bed boiler.
Compared with the prior art, the invention has the following advantages:
1. compared with the traditional production of pseudo-boehmite, the raw material cost of the fly ash is low, and hydrochloric acid can be recycled in the production process of the fly ash-crystalline aluminum chloride, such as: in the roasting process of the crystalline aluminum chloride, a large amount of chloride ions enter roasting smoke in the form of hydrogen chloride gas, and the hydrogen chloride gas is absorbed by water in a factory to obtain hydrochloric acid which is then used for reacting with the fly ash.
2. The utilization rate of aluminum in the fly ash is high and can reach more than 75 percent; wherein, during the acid leaching of the fly ash: under the conditions of ensuring the material ratio, the temperature and the time, 85 percent of aluminum in the fly ash can be leached into the solution at the stage, and the leaching rate is low due to insufficient acid, low temperature and short reaction time; secondly, extracting aluminum residues and removing impurities: the loss of aluminium at this stage is around 5%; the residue after aluminum extraction is not washed cleanly, and can carry a part of aluminum; part of aluminum is lost during resin regeneration in the impurity removal stage; furthermore, in the hydrothermal process: because the crystal roasting temperature is 200-500 ℃, a part of aluminum chloride is not completely decomposed into aluminum oxide, and the aluminum chloride enters the solution in the hydrothermal process to cause loss. Although the aluminum loss can be reduced by increasing the crystal baking temperature (more than 400 ℃), the crystal transformation of the activated alumina is not facilitated by high-temperature baking. Therefore, the matching of the parameters and the steps in the preparation method of the invention in the stages maximizes the utilization rate of aluminum in the fly ash.
3. The hydrothermal reaction adopted by the invention has mild crystal transformation conditions and simple working conditions.
In conclusion, the intermediate product, namely the crystalline aluminum chloride, in the process of producing the alumina by the coal ash hydrochloric acid method adopted by the invention can be decomposed into the activated alumina in a low-temperature roasting state, has higher reaction free energy and high reaction activity, and the activated alumina is easy to generate crystal form transformation under the hydrothermal condition, so that a new thought and method are provided for preparing the pseudo-boehmite. The product produced by the traditional method has high sodium ion content, is difficult to clean and remove, and has large water consumption for washing. The product of the method has extremely low content of sodium ions.
Therefore, the invention solves the problem of environmental pollution caused by long-term storage of the fly ash, reasonably utilizes the aluminum resource in the high-alumina fly ash, develops a brand-new method for preparing the pseudo-boehmite by taking the fly ash as the raw material, widens the product channel of comprehensive utilization of the fly ash and produces high value-added products.
Drawings
FIG. 1 is an XRD pattern of a pseudo-boehmite product obtained in example 1 of the present invention.
Detailed Description
The present invention will be further described with reference to the following examples and the accompanying drawings, but the present invention is not limited to the examples listed, and shall include equivalent modifications and variations of the technical solutions defined in the claims appended to the present application.
The embodiment of the invention provides a method for preparing pseudo-boehmite by utilizing fly ash, which mainly comprises the following steps:
1) leaching the fly ash with acid liquor to obtain a leaching material; carrying out solid-liquid separation on the leaching material to obtain a leaching solution and a residue of extracting aluminum from the fly ash;
2) removing impurities from the leaching solution, and removing iron ions and calcium ions to obtain a pure aluminum chloride solution;
3) evaporating and crystallizing the pure aluminum chloride solution to obtain aluminum chloride crystals;
4) roasting the aluminum chloride crystal to obtain activated alumina;
5) mixing activated alumina with water, and carrying out hydrothermal reaction to obtain a pseudo-boehmite aqueous solution;
6) and carrying out solid-liquid separation on the pseudo-boehmite aqueous solution to obtain a pseudo-boehmite product.
The raw material fly ash adopted by the invention is high-alumina fly ash discharged by a circulating fluidized bed boiler of a certain power plant from inner Mongolia, and the hydrochloric acid is industrial hydrochloric acid (mass fraction is 31%).
The iron removing resin is macroporous cation resin, the calcium removing resin is resin of the applicant company, and the patent CN201710806979.5 can be referred to for calcium removal.
Other materials used in the examples of the present invention are commercially available unless otherwise specified.
Example 1
2kg of high-alumina fly ash is uniformly mixed with 5.4L of hydrochloric acid, and the mixture is fed into a reaction kettle for leaching at the temperature of 140 ℃ for 6 hours. Filtering the leached slurry by using a plate-and-frame filter, and washing the aluminum extraction residue to obtain 6.5L of leaching filtrate (mixed solution of a leaching stock solution and a washing solution), wherein the concentration of aluminum chloride is 240 g/L;
and (3) sequentially passing the leaching filtrate through ion exchange resin to remove iron ions and calcium ions, wherein the flow rate is 1Bv/h, the temperature is 30 ℃, and 5.2L of pure aluminum chloride solution is obtained after impurity removal. Evaporating and crystallizing the pure aluminum chloride solution (the evaporation temperature is 110 ℃) until aluminum chloride crystals are separated out to obtain crystalline aluminum chloride AlCl3.6H2O is 1.65 kg;
0.5kg of crystalline aluminum chloride is taken and roasted for 6 hours at 350 ℃ in the air atmosphere to obtain 120g of amorphous alumina intermediate product;
carrying out hydrothermal reaction on the amorphous alumina intermediate product in a high-pressure kettle for 4 hours by using 1L of pure water, and obtaining a pseudo-boehmite aqueous solution at the dissolution temperature of 180 ℃;
and (3) centrifugally separating the pseudo-boehmite aqueous solution, washing the pseudo-boehmite aqueous solution for 2 times by pure water, and drying the pseudo-boehmite aqueous solution at 100 ℃ to obtain a pseudo-boehmite product. FIG. 1 is an XRD pattern of a pseudo-boehmite product obtained in example 1 of the present invention.
The obtained pseudoboehmite comprises the following components: na (Na)2The content of O: 50ppm, SiO2Content 80ppm, Fe2O3The content was 100ppm and the CaO content was 150 ppm. The aluminum utilization rate (alumina content in pseudo-boehmite/alumina content in fly ash) x 100%. The utilization rate of aluminum in the fly ash is 77 percent through calculation.
Example 2
In example 1, the calcination temperature of crystalline aluminum chloride was adjusted to 300 ℃ and the other conditions were not changed. The aluminum utilization rate of the obtained pseudo-boehmite product in the fly ash is 73 percent.
Example 3
On the basis of example 1, amorphous alumina intermediate was hydrated with 360ml of pure water in an autoclaveThe reaction was heated for 1 hour, and the other conditions were unchanged. The obtained pseudoboehmite comprises the following components: na (Na)2The content of O: 94ppm, SiO2Content 120ppm, Fe2O3160ppm of CaO and 280ppm of CaO. The temperature, water consumption and time in the hydrothermal reaction all influence the impurity content of the product. Example 3 demonstrates that the impurity level increases with low water levels and short reaction times.
Example 4
The hydrothermal temperature was adjusted to 160 ℃ in example 1, and the other conditions were not changed. The obtained pseudoboehmite comprises the following components: na (Na)2The content of O: 120ppm, SiO2Content 95ppm, Fe2O3140ppm of CaO and 260ppm of CaO. When the hydrothermal temperature is reduced from 180 ℃ to 160 ℃, the impurity content is increased.
Example 5
On the basis of example 1, the leaching temperature is 120 ℃, the leaching time is 8 hours, and the mass ratio of the high-alumina fly ash to hydrochloric acid is 1: 3, the concentration of aluminum chloride in the leachate obtained by leaching with the acid solution is 300g/L, and other conditions are unchanged. The aluminum utilization rate of the obtained pseudo-boehmite product in the fly ash is 72 percent. When the leaching temperature is low (120 ℃), the leaching rate of aluminum is low, and the utilization rate of fly ash is low.
Example 6
On the basis of example 1, the leaching temperature is 120 ℃, the leaching time is 8 hours, and the mass ratio of the high-alumina fly ash to hydrochloric acid is 1: 3, the concentration of aluminum chloride in the leachate obtained by leaching with the acid liquor is 300 g/L; when the leachate passes through iron-removing ion exchange resin and calcium-removing ion exchange resin in sequence, the flow rate is 5Bv/h, and the temperature is 40 ℃; the evaporation temperature is 110 ℃, the roasting temperature of the crystallized aluminum chloride is adjusted to 250 ℃, and other conditions are not changed. The aluminum utilization rate of the obtained pseudo-boehmite product in the fly ash is 71 percent. When the calcination temperature of the crystalline aluminum chloride is low (250 ℃), the conversion of aluminum chloride to alumina is incomplete, resulting in a low recovery rate of aluminum.
Comparative example 1
On the basis of example 1, the roasting temperature of the crystalline aluminum chloride is adjusted to 600 ℃, other conditions are unchanged, the crystalline aluminum chloride is still alumina after hydrothermal reaction, and a pseudo-boehmite product cannot be obtained.
Comparative example 2
Adopts the traditional carbonization method to produce the pseudoboehmite, and CO is introduced into the sodium aluminate solution2Decomposing into gel, heating and aging for a certain time, separating, washing, press-filtering and drying to obtain the pseudoboehmite product. The washing water consumption is 40-60 t/t-product, and Na in the product2The content of O: 2500ppm, high sodium ion content.
Those skilled in the art understand that the content values of each component in the pseudoboehmite can be obtained by adopting a corresponding conventional method in the field, and are not described in detail.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. Not all embodiments are exhaustive. All obvious changes or modifications of the technical solution of the present invention are within the spirit of the present invention.
Claims (10)
1. A method for preparing pseudo-boehmite by utilizing fly ash is characterized by comprising the following steps: the method comprises the following steps:
1) leaching the fly ash with acid liquor to obtain a leaching material; carrying out solid-liquid separation on the leaching material to obtain a leaching solution and a residue of extracting aluminum from the fly ash;
2) removing impurities from the leaching solution, and removing iron ions and calcium ions to obtain a pure aluminum chloride solution;
3) evaporating and crystallizing the pure aluminum chloride solution to obtain aluminum chloride crystals;
4) roasting the aluminum chloride crystal to obtain activated alumina;
5) mixing the activated alumina with water, and then carrying out hydrothermal reaction to obtain a pseudo-boehmite aqueous solution;
6) and carrying out solid-liquid separation on the pseudo-boehmite aqueous solution to obtain a pseudo-boehmite product.
2. The method of preparing pseudoboehmite according to claim 1, characterized in that: in the step 1), the acid solution is preferably hydrochloric acid, and the concentration of the hydrochloric acid is preferably 20-38% by mass, and is further preferably 25-35%; the leaching temperature is 110-170 ℃, preferably 120-140 ℃, and the leaching time is 2-8 hours;
preferably, the mass ratio of the fly ash to the hydrochloric acid is 1: 2.5-1: 3.5, the concentration of the aluminum chloride in the leachate obtained by leaching with the acid solution is 200-350 g/L.
3. The method for preparing pseudoboehmite according to claim 1 or 2, characterized in that: further comprising: washing the residue after extracting aluminum from the fly ash, and merging the obtained washing liquid into the leaching solution.
4. The method for producing pseudoboehmite according to any one of claims 1-3, characterized in that: in the step 2), the impurity removal of the leachate comprises the following steps: the leachate passes through iron-removing ion exchange resin and calcium-removing ion exchange resin in turn, wherein the concentration of aluminum chloride is controlled to be 180-320g/L, the flow rate is 1-5Bv/h, and the temperature is 20-80 ℃, preferably 20-40 ℃.
5. The method for producing pseudoboehmite according to any one of claims 1-4, characterized in that: in the step 3), the evaporation temperature is 60-130 ℃.
6. The method for producing pseudoboehmite according to any one of claims 1-5, characterized in that: in the step 4), the roasting temperature of the aluminum chloride crystal is 200-.
7. The method for producing pseudoboehmite according to any one of claims 1-6, characterized in that: in the step 5), mixing activated alumina and water according to a mass ratio of 1: 3-1: 15, mixing; the hydrothermal reaction temperature is 100-250 ℃, preferably 150-200 ℃, more preferably 180 ℃, and the hydrothermal reaction time is preferably 2-6 hours, more preferably 3-4 hours.
8. The method for preparing pseudoboehmite according to claim 1-7, characterized in that: and 6), performing solid-liquid separation on the pseudo-boehmite by adopting a filter pressing or centrifugal separation mode.
9. The method of preparing pseudoboehmite according to claim 8, characterized in that: and (3) carrying out solid-liquid separation on the pseudo-boehmite to obtain a solid, washing the solid for 2 times by using pure water, and drying a washed filter cake at the temperature of 80-120 ℃ to obtain the pseudo-boehmite product.
10. The method for producing pseudoboehmite according to any one of claims 1-9, characterized in that: the fly ash is high-alumina fly ash.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115504493A (en) * | 2022-11-07 | 2022-12-23 | 神华准能资源综合开发有限公司 | Method for preparing alumina aerogel from crystalline aluminum chloride |
| CN115771910A (en) * | 2022-12-19 | 2023-03-10 | 神华准能资源综合开发有限公司 | Method for preparing metallurgical-grade aluminum oxide by using fly ash acid method |
| CN115924949A (en) * | 2022-12-28 | 2023-04-07 | 神华准能资源综合开发有限公司 | Industrial modification method of fly ash acid-process alumina |
| CN115947358A (en) * | 2022-12-16 | 2023-04-11 | 神华准能资源综合开发有限公司 | Method for producing alumina |
| CN116282104A (en) * | 2022-12-28 | 2023-06-23 | 神华准能资源综合开发有限公司 | Method for producing boehmite |
| CN116375062A (en) * | 2022-12-26 | 2023-07-04 | 神华准能资源综合开发有限公司 | Method for preparing aluminum ammonium carbonate by using fly ash |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102145905A (en) * | 2010-04-27 | 2011-08-10 | 中国神华能源股份有限公司 | Method for preparing metallurgy-level aluminum oxide by using fluidized bed pulverized fuel ash |
| CN103964480A (en) * | 2014-05-26 | 2014-08-06 | 刘艳霞 | Process for producing aluminum oxide by using hydrochloric acid method |
| CN110902703A (en) * | 2019-12-27 | 2020-03-24 | 神华准能资源综合开发有限公司 | Method for producing alumina and recovering rare earth elements by using coal ash hydrochloric acid method |
-
2021
- 2021-09-30 CN CN202111164395.5A patent/CN113929125A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102145905A (en) * | 2010-04-27 | 2011-08-10 | 中国神华能源股份有限公司 | Method for preparing metallurgy-level aluminum oxide by using fluidized bed pulverized fuel ash |
| CN103964480A (en) * | 2014-05-26 | 2014-08-06 | 刘艳霞 | Process for producing aluminum oxide by using hydrochloric acid method |
| CN110902703A (en) * | 2019-12-27 | 2020-03-24 | 神华准能资源综合开发有限公司 | Method for producing alumina and recovering rare earth elements by using coal ash hydrochloric acid method |
Non-Patent Citations (4)
| Title |
|---|
| 李文清: "结晶氯化铝两步焙烧制备氧化铝的研究", 有色金属(冶炼部分), no. 1, pages 40 - 45 * |
| 李晓云: "活性氧化铝再水合制备拟薄水铝石的形态研究" * |
| 李晓云: "活性氧化铝再水合制备拟薄水铝石的形态研究", 电子显微学报, vol. 30, no. 6, pages 517 - 520 * |
| 王宏宾: "粉煤灰盐酸法提取氧化铝技术研究", 现代化工, vol. 40, no. 8, pages 194 - 197 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115504493A (en) * | 2022-11-07 | 2022-12-23 | 神华准能资源综合开发有限公司 | Method for preparing alumina aerogel from crystalline aluminum chloride |
| CN115504493B (en) * | 2022-11-07 | 2023-11-28 | 神华准能资源综合开发有限公司 | Method for preparing alumina aerogel from crystallized aluminum chloride |
| CN115947358A (en) * | 2022-12-16 | 2023-04-11 | 神华准能资源综合开发有限公司 | Method for producing alumina |
| CN115771910A (en) * | 2022-12-19 | 2023-03-10 | 神华准能资源综合开发有限公司 | Method for preparing metallurgical-grade aluminum oxide by using fly ash acid method |
| CN116375062A (en) * | 2022-12-26 | 2023-07-04 | 神华准能资源综合开发有限公司 | Method for preparing aluminum ammonium carbonate by using fly ash |
| CN115924949A (en) * | 2022-12-28 | 2023-04-07 | 神华准能资源综合开发有限公司 | Industrial modification method of fly ash acid-process alumina |
| CN116282104A (en) * | 2022-12-28 | 2023-06-23 | 神华准能资源综合开发有限公司 | Method for producing boehmite |
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